WorldWideScience

Sample records for non-abelian field theories

  1. Non-Abelian gauge field theory in scale relativity

    International Nuclear Information System (INIS)

    Nottale, Laurent; Celerier, Marie-Noeelle; Lehner, Thierry

    2006-01-01

    Gauge field theory is developed in the framework of scale relativity. In this theory, space-time is described as a nondifferentiable continuum, which implies it is fractal, i.e., explicitly dependent on internal scale variables. Owing to the principle of relativity that has been extended to scales, these scale variables can themselves become functions of the space-time coordinates. Therefore, a coupling is expected between displacements in the fractal space-time and the transformations of these scale variables. In previous works, an Abelian gauge theory (electromagnetism) has been derived as a consequence of this coupling for global dilations and/or contractions. We consider here more general transformations of the scale variables by taking into account separate dilations for each of them, which yield non-Abelian gauge theories. We identify these transformations with the usual gauge transformations. The gauge fields naturally appear as a new geometric contribution to the total variation of the action involving these scale variables, while the gauge charges emerge as the generators of the scale transformation group. A generalized action is identified with the scale-relativistic invariant. The gauge charges are the conservative quantities, conjugates of the scale variables through the action, which find their origin in the symmetries of the ''scale-space.'' We thus found in a geometric way and recover the expression for the covariant derivative of gauge theory. Adding the requirement that under the scale transformations the fermion multiplets and the boson fields transform such that the derived Lagrangian remains invariant, we obtain gauge theories as a consequence of scale symmetries issued from a geometric space-time description

  2. Classical field theory on electrodynamics, non-Abelian gauge theories and gravitation

    CERN Document Server

    Scheck, Florian

    2012-01-01

    The book describes Maxwell's equations first in their integral, directly testable form, then moves on to their local formulation. The first two chapters cover all essential properties of Maxwell's equations, including their symmetries and their covariance in a modern notation. Chapter 3 is devoted to Maxwell theory as a classical field theory and to solutions of the wave equation. Chapter 4 deals with important applications of Maxwell theory. It includes topical subjects such as metamaterials with negative refraction index and solutions of Helmholtz' equation in paraxial approximation relevant for the description of laser beams. Chapter 5 describes non-Abelian gauge theories from a classical, geometric point of view, in analogy to Maxwell theory as a prototype, and culminates in an application to the U(2) theory relevant for electroweak interactions. The last chapter 6 gives a concise summary of semi-Riemannian geometry as the framework for the classical field theory of gravitation. The chapter concludes wit...

  3. Classical field theory on electrodynamics, non-abelian gauge theories and gravitation

    CERN Document Server

    Scheck, Florian

    2018-01-01

    Scheck’s successful textbook presents a comprehensive treatment, ideally suited for a one-semester course. The textbook describes Maxwell's equations first in their integral, directly testable form, then moves on to their local formulation. The first two chapters cover all essential properties of Maxwell's equations, including their symmetries and their covariance in a modern notation. Chapter 3 is devoted to Maxwell's theory as a classical field theory and to solutions of the wave equation. Chapter 4 deals with important applications of Maxwell's theory. It includes topical subjects such as metamaterials with negative refraction index and solutions of Helmholtz' equation in paraxial approximation relevant for the description of laser beams. Chapter 5 describes non-Abelian gauge theories from a classical, geometric point of view, in analogy to Maxwell's theory as a prototype, and culminates in an application to the U(2) theory relevant for electroweak interactions. The last chapter 6 gives a concise summary...

  4. Non-Abelian solitons in two-dimensional lattice field theories

    Science.gov (United States)

    Müller, V. F.

    1993-12-01

    For a class of self-interacting multicomponent scalar field theories with a global discrete non-Abelian symmetry group, mixed order-disorder correlation functions are defined in terms of Euclidean functional integrals. These correlation functions satisfy Osterwalder-Schrader positivity. From a representation of the correlation functions in terms of the transfer matrix, the dual algebra at fixed time is derived. This algebra implies parafermion operators showing non-Abelian braid group statistics. In a pure phase of spontaneous symmetry breaking for a related class of order-disorder correlation functions a convergent polymer representation is developed, emerging from a combined low- and high-temperature-type expansion. The infinite volume correlation functions of this class show exponential clustering in the disorder fields.

  5. Non-Abelian gauge fields

    Science.gov (United States)

    Gerbier, Fabrice; Goldman, Nathan; Lewenstein, Maciej; Sengstock, Klaus

    2013-07-01

    -orbit coupling (Rashba and Dresselhaus couplings), familiar from AMO and condensed matter physics. They lead to yet another variety of fascinating phenomena such as the quantum spin Hall effect, three-dimensional topological insulators, topological superconductors and superfluids of various kinds. One also expects here the appearance of excitations in a form of topological edge states that can support robust transport, or entangled Majorana fermions in the case of topological superconductors or superfluids. Again, while many kinds of topological insulators have been realized in condensed matter systems, a controlled way of creating them in AMO systems and studying quantum phase transitions between various kinds of them is obviously very appealing and challenging. The various systems listed so far correspond to static gauge fields, which are externally imposed by the experimentalists. Even more fascinating is the possibility of generating synthetically dynamical gauge fields, i.e. gauge fields that evolve in time according to an interacting gauge theory, e.g., a full lattice gauge theory (LGT). These dynamical gauge fields can also couple to matter fields, allowing the quantum simulation of such complex systems (notoriously hard to simulate using 'traditional' computers), which are particularly relevant for modern high-energy physics. So far, most of the theoretical proposals concern the simulation of Abelian gauge theories, however, several groups have recently proposed extensions to the non-Abelian scenarios. The scope of the present focused issue of Journal of Physics B is to cover all of these developments, with particular emphasis on the non-Abelian gauge fields. The 14 papers in this issue include contributions from the leading theory groups working in this field; we believe that this collection will provide the reference set for quantum simulations of gauge fields. Although the special issue contains exclusively theoretical proposals and studies, it should be stressed that

  6. Quantum field theory I foundations and Abelian and non-Abelian gauge theories

    CERN Document Server

    Manoukian, Edouard B

    2016-01-01

    This textbook covers a broad spectrum of developments in QFT, emphasizing those aspects that are now well consolidated and for which satisfactory theoretical descriptions have been provided. The book is unique in that it offers a new approach to the subject and explores many topics merely touched upon, if covered at all, in standard reference works. A detailed and largely non-technical introductory chapter traces the development of QFT from its inception in 1926. The elegant functional differential approach put forward by Schwinger, referred to as the quantum dynamical (action) principle, and its underlying theory are used systematically in order to generate the so-called vacuum-to-vacuum transition amplitude of both abelian and non-abelian gauge theories, in addition to Feynman’s well-known functional integral approach, referred to as the path-integral approach. Given the wealth of information also to be found in the abelian case, equal importance is put on both abelian and non-abelian gauge theories. Pa...

  7. Spatial geometry of the electric field representation of non-abelian gauge theories

    CERN Document Server

    Bauer, M; Haagensen, P E; Michel Bauer; Daniel Z Freedman; Peter E Haagensen

    1994-01-01

    A unitary transformation \\Ps [E]=\\exp (i\\O [E]/g) F[E] is used to simplify the Gauss law constraint of non-abelian gauge theories in the electric field representation. This leads to an unexpected geometrization because \\o^a_i\\equiv -\\d\\O [E]/\\d E^{ai} transforms as a (composite) connection. The geometric information in \\o^a_i is transferred to a gauge invariant spatial connection \\G^i_{jk} and torsion by a suitable choice of basis vectors for the adjoint representation which are constructed from the electric field E^{ai}. A metric is also constructed from E^{ai}. For gauge group SU(2), the spatial geometry is the standard Riemannian geometry of a 3-manifold, and for SU(3) it is a metric preserving geometry with both conventional and unconventional torsion. The transformed Hamiltonian is local. For a broad class of physical states, it can be expressed entirely in terms of spatial geometric, gauge invariant variables.

  8. High-energy behavior of non-Abelian gauge theories

    International Nuclear Information System (INIS)

    Nieh, H.T.; Yao, Y.

    1976-01-01

    This paper is a detailed account of a study in perturbation theory of the high-energy behavior of non-Abelian gauge theories. The fermion-fermion scattering amplitude is calculated up to sixth order in the coupling constant in the high-energy limit s → infinity with fixed t, in the approximation of keeping only the leading logarithmic terms. Results indicate that the high-energy behavior of non-Abelian gauge theories are complicated, and quite different from the known behaviors of other field theories studied so far

  9. Energy-momentum tensor in theories with scalar fields and two coupling constants. I. Non-Abelian case

    International Nuclear Information System (INIS)

    Joglekar, S.D.; Misra, A.

    1989-01-01

    In this paper, we generalize our earlier discussion of renormalization of the energy-momentum tensor in scalar QED to that in non-Abelian gauge theories involving scalar fields. We show the need for adding an improvement term to the conventional energy-momentum tensor. We consider two possible forms for the improvement term: (i) one in which the improvement coefficient is a finite function of bare parameters of the theory (so that the energy-momentum tensor can be derived from an action that is a finite function of bare quantities); (ii) one in which the improvement coefficient is a finite quantity, i.e., a finite function of renormalized parameters. We establish a negative result; viz., neither form leads to a finite energy-momentum tensor to O(e 2 λ/sup n/)

  10. Problem of colour confinement in non-Abelian gauge theories

    International Nuclear Information System (INIS)

    Gribov, V.N.

    1978-01-01

    The problem of the colour confinement in the non-abelian gauge theories is studied. A more rigorous treatment of the Fadeev-Popov procedure for the quantization of the non-abelian gauge theories is presented. In the improved procedure one has to introduce additional bounds on the region of integration in the functional space of non-abelian fields. The integration is to be performed over the fields with positive-definite Faddeev-Popov determinant. This limitation has little influence on oscillations with high frequencies, but reduces drastically the amplitudes of low-frequency oscillations. This implies, that interaction of two colour charges does not go into infinity at finite distances, rather it is linearly rising with distance

  11. The chiral bosonization in non-Abelian gauge theories

    International Nuclear Information System (INIS)

    Andrianov, A.A.; Novozhilov, Y.

    1985-01-01

    The chiral bosonization in non-Abelian gauge theories is described starting directly from the QCD functional. For a given mass scale Λ, the QCD may be equivalently represented by colour chiral fields, gauge fields and high energy fermions. The effective action for colour chiral fields may admit the existence of a colour Skyrmion-boson with the baryon number 2/3. (author)

  12. Worldlines and worldsheets for non-abelian lattice field theories: Abelian color fluxes and Abelian color cycles

    Science.gov (United States)

    Gattringer, Christof; Göschl, Daniel; Marchis, Carlotta

    2018-03-01

    We discuss recent developments for exact reformulations of lattice field theories in terms of worldlines and worldsheets. In particular we focus on a strategy which is applicable also to non-abelian theories: traces and matrix/vector products are written as explicit sums over color indices and a dual variable is introduced for each individual term. These dual variables correspond to fluxes in both, space-time and color for matter fields (Abelian color fluxes), or to fluxes in color space around space-time plaquettes for gauge fields (Abelian color cycles). Subsequently all original degrees of freedom, i.e., matter fields and gauge links, can be integrated out. Integrating over complex phases of matter fields gives rise to constraints that enforce conservation of matter flux on all sites. Integrating out phases of gauge fields enforces vanishing combined flux of matter-and gauge degrees of freedom. The constraints give rise to a system of worldlines and worldsheets. Integrating over the factors that are not phases (e.g., radial degrees of freedom or contributions from the Haar measure) generates additional weight factors that together with the constraints implement the full symmetry of the conventional formulation, now in the language of worldlines and worldsheets. We discuss the Abelian color flux and Abelian color cycle strategies for three examples: the SU(2) principal chiral model with chemical potential coupled to two of the Noether charges, SU(2) lattice gauge theory coupled to staggered fermions, as well as full lattice QCD with staggered fermions. For the principal chiral model we present some simulation results that illustrate properties of the worldline dynamics at finite chemical potentials.

  13. Worldlines and worldsheets for non-abelian lattice field theories: Abelian color fluxes and Abelian color cycles

    Directory of Open Access Journals (Sweden)

    Gattringer Christof

    2018-01-01

    Full Text Available We discuss recent developments for exact reformulations of lattice field theories in terms of worldlines and worldsheets. In particular we focus on a strategy which is applicable also to non-abelian theories: traces and matrix/vector products are written as explicit sums over color indices and a dual variable is introduced for each individual term. These dual variables correspond to fluxes in both, space-time and color for matter fields (Abelian color fluxes, or to fluxes in color space around space-time plaquettes for gauge fields (Abelian color cycles. Subsequently all original degrees of freedom, i.e., matter fields and gauge links, can be integrated out. Integrating over complex phases of matter fields gives rise to constraints that enforce conservation of matter flux on all sites. Integrating out phases of gauge fields enforces vanishing combined flux of matter-and gauge degrees of freedom. The constraints give rise to a system of worldlines and worldsheets. Integrating over the factors that are not phases (e.g., radial degrees of freedom or contributions from the Haar measure generates additional weight factors that together with the constraints implement the full symmetry of the conventional formulation, now in the language of worldlines and worldsheets. We discuss the Abelian color flux and Abelian color cycle strategies for three examples: the SU(2 principal chiral model with chemical potential coupled to two of the Noether charges, SU(2 lattice gauge theory coupled to staggered fermions, as well as full lattice QCD with staggered fermions. For the principal chiral model we present some simulation results that illustrate properties of the worldline dynamics at finite chemical potentials.

  14. Non-Abelian formulation of a vector-tensor gauge theory with topological coupling

    Energy Technology Data Exchange (ETDEWEB)

    Barcelos-Neto, J. [International Centre for Theoretical Physics, Trieste (Italy); Cabo, A. [International Centre for Theoretical Physics, Trieste (Italy); Silva, M.B.D. [Univ. Federal do Rio de Janeiro (Brazil). Inst. de Fisica

    1996-10-01

    We obtain a non-Abelian version of a theory involving vector and tensor gauge fields interacting via a massive topological coupling, besides the nonminimun one. The new fact is that the non-Abelian theory is not reducible and Stuckelberg fields are introduced in order to make compatible gauge invariance, nontrivial physical degrees of freedom and the limit of the Abelian case. (orig.)

  15. Bosonization of three-dimensional non-abelian fermion field theories

    International Nuclear Information System (INIS)

    Bralic, N.; Manias, V.; Schaposnik, F.A.

    1995-01-01

    We discuss bosonization in three dimensions of an SU(N) massive Thirring model in the low-energy regime. We find that the bosonized theory is related (but not equal) to SU(N) Yang-Mills-Chern-Simons gauge theory. For free massive fermions bosonization leads, at low energies, to the pure SU(N) (level k=1) Chern-Simons theory. (orig.)

  16. Bosonization of three-dimensional non-abelian fermion field theories

    Energy Technology Data Exchange (ETDEWEB)

    Bralic, N. [Pontificia Universidad Catolica de Chile, Santiago (Chile). Facultad de Fisica; Fradkin, E. [Department of Physics, University of Illinois at Urbana-Champaign, 1110 W. Green St., Urbana, IL 61801-3080 (United States); Manias, V. [Departamento de Fisica, Universidad Nacional de La Plata, C.C. 67, (1900), La Plata (Argentina); Schaposnik, F.A. [Departamento de Fisica, Universidad Nacional de La Plata, C.C. 67, (1900), La Plata (Argentina)

    1995-07-17

    We discuss bosonization in three dimensions of an SU(N) massive Thirring model in the low-energy regime. We find that the bosonized theory is related (but not equal) to SU(N) Yang-Mills-Chern-Simons gauge theory. For free massive fermions bosonization leads, at low energies, to the pure SU(N) (level k=1) Chern-Simons theory. (orig.).

  17. On the relation between fields and potentials in non abelian Gauge Theories

    International Nuclear Information System (INIS)

    Bollini, C.G.; Giambiagi, J.J.

    1979-01-01

    Some examples have been given in the literature of ambiguous gauge fields, i.e. those not having a unique potential (up to a gauge transformation). An example given by Deser and Wilczek is examined and found the condition (for any gauge group) that the group element generating the potentials must satisfy in order for the potentials not to be related by any gauge transformation. In three dimensions (for Su 2 ) there are other families of ambiguous fields characterized by arbitrary unit vector fields n vector (n vector) (n 2 vector =1). The example given by Wu and Yang belongs to a particular family with n vector = n vector. r vector / r vector. The sources of these fields and some interesting relations between them are also found [pt

  18. Non-Abelian Gauge Theory in the Lorentz Violating Background

    Science.gov (United States)

    Ganai, Prince A.; Shah, Mushtaq B.; Syed, Masood; Ahmad, Owais

    2018-03-01

    In this paper, we will discuss a simple non-Abelian gauge theory in the broken Lorentz spacetime background. We will study the partial breaking of Lorentz symmetry down to its sub-group. We will use the formalism of very special relativity for analysing this non-Abelian gauge theory. Moreover, we will discuss the quantisation of this theory using the BRST symmetry. Also, we will analyse this theory in the maximal Abelian gauge.

  19. Higgs phase in non-Abelian gauge theories

    International Nuclear Information System (INIS)

    Kaymakcalan, O.S.

    1981-06-01

    A non-Abelian gauge theory involving scalar fields with non-tachyonic mass terms in the Lagrangian is considered, in order to construct a finite energy density trial vacuum for this theory. The usual scalar potential arguments suggest that the vacuum of such a theory would be in the perturbative phase. However, the obvious choices for a vacuum in this phase, the Axial gauge and the Coulomb gauge bare vacua, do not have finite energy densities even with an ultraviolet cutoff. Indeed, it is a non-trivial problem to construct finite energy density vacua for non-Abelian gauge theories and this is intimately connected with the gauge fixing degeneracies of these theories. Since the gauge fixing is achieved in the Unitary gauge, this suggests that the Unitary gauge bare vacuum might be a finite energy trial vacuum and, despite the form of the scalar potential, the vacuum of this theory might be in a Higgs phase rather than the perturbative phase

  20. Non-abelian gauge fields in the Poincare gauge

    International Nuclear Information System (INIS)

    Galvao, C.A.P.; Pimentel, B.M.

    1988-01-01

    The canonical structure of non-Abelian gauge fields is analysed in the (non-covariant) Poincare gauge. General aspects of the gauge conditions and quantization prescriptions are discussed. (author) [pt

  1. Classical and quantum mechanics of non-abelian gauge fields

    International Nuclear Information System (INIS)

    Savvidy, G.K.

    1984-01-01

    Classical and quantum mechanics of non-abelian gauge fields are investigated both with and without spontaneous symmetry breaking. The fundamental subsystem (FS) of Yang-Mills classical mechanics (YMCM) is considered. It is shown to be a Kolmogorov K-system, and hence to have strong statistical properties. Integrable systems are also found, to which in terms of KAM theory Yang-Mills-Higgs classical mechanics (YMHCM) is close. Quantum-mechanical properties of the YM system and their relation to the problem of confinement are discussed. (orig.)

  2. Hidden singularities in non-abelian gauge fields

    International Nuclear Information System (INIS)

    Bollini, C.G.; Giambiagi, J.J.; Tiomno, J.

    1978-01-01

    It is shown that the potential (and field) of a non-abelian gauge theory is not well determined when it has a singular point. When this is the cause, it is important to specify the regularization procedure used to give a precise definition of physical quantities at the singularity at any stage of the computation. The fact that a certain A sub(μ) (associated with the given regularization) represents the vacuum when F sub(μν) is a zero distribution not only on the global space but also in all its projections to arbitrary subspaces is discussed. The example used as a base for the discussion is A vetor = i (sigma vetor Λ r vetor / r 2 ). For this example it is shown that different regularizations give the same field in the global space but they give different distributions when projected to subspaces containing the singular point [pt

  3. $N=2^∗$ (non-)Abelian theory in the $\\Omega$ background from string theory

    CERN Document Server

    Samsonyan, Marine; Antoniadis, Ignatios

    2018-01-01

    We present a D-brane realisation of the Abelian and non-Abelian N = 2 ∗ theory both in five and four dimensions. We compute topological amplitudes in string theory for Ω deformed spacetime first with one and then with two parameters. In the field theory limit we recover the perturbative partition function of the deformed N = 2 ∗ theory in agreement with the existing literature.

  4. Scalar formalism for non-Abelian gauge theory

    International Nuclear Information System (INIS)

    Hostler, L.C.

    1986-01-01

    The gauge field theory of an N-dimensional multiplet of spin- 1/2 particles is investigated using the Klein--Gordon-type wave equation ]Pi x (1+isigma) x Pi+m 2 ]Phi = 0, Pi/sub μ/equivalentpartial/partialix/sub μ/-eA/sub μ/, investigated before by a number of authors, to describe the fermions. Here Phi is a 2 x 1 Pauli spinor, and sigma repesents a Lorentz spin tensor whose components sigma/sub μ//sub ν/ are ordinary 2 x 2 Pauli spin matrices. Feynman rules for the scalar formalism for non-Abelian gauge theory are derived starting from the conventional field theory of the multiplet and converting it to the new description. The equivalence of the new and the old formalism for arbitrary radiative processes is thereby established. The conversion to the scalar formalism is accomplished in a novel way by working in terms of the path integral representation of the generating functional of the vacuum tau-functions, tau(2,1, xxx 3 xxx)equivalent , where Psi/sub in/ is a Heisenberg operator belonging to a 4N x 1 Dirac wave function of the multiplet. The Feynman rules obtained generalize earlier results for the Abelian case of quantum electrodynamics

  5. Diagrammatic Monte Carlo for the weak-coupling expansion of non-Abelian lattice field theories: Large-N U (N ) ×U (N ) principal chiral model

    Science.gov (United States)

    Buividovich, P. V.; Davody, A.

    2017-12-01

    We develop numerical tools for diagrammatic Monte Carlo simulations of non-Abelian lattice field theories in the t'Hooft large-N limit based on the weak-coupling expansion. First, we note that the path integral measure of such theories contributes a bare mass term in the effective action which is proportional to the bare coupling constant. This mass term renders the perturbative expansion infrared-finite and allows us to study it directly in the large-N and infinite-volume limits using the diagrammatic Monte Carlo approach. On the exactly solvable example of a large-N O (N ) sigma model in D =2 dimensions we show that this infrared-finite weak-coupling expansion contains, in addition to powers of bare coupling, also powers of its logarithm, reminiscent of resummed perturbation theory in thermal field theory and resurgent trans-series without exponential terms. We numerically demonstrate the convergence of these double series to the manifestly nonperturbative dynamical mass gap. We then develop a diagrammatic Monte Carlo algorithm for sampling planar diagrams in the large-N matrix field theory, and apply it to study this infrared-finite weak-coupling expansion for large-N U (N ) ×U (N ) nonlinear sigma model (principal chiral model) in D =2 . We sample up to 12 leading orders of the weak-coupling expansion, which is the practical limit set by the increasingly strong sign problem at high orders. Comparing diagrammatic Monte Carlo with conventional Monte Carlo simulations extrapolated to infinite N , we find a good agreement for the energy density as well as for the critical temperature of the "deconfinement" transition. Finally, we comment on the applicability of our approach to planar QCD at zero and finite density.

  6. The non-Abelian gauge theory of matrix big bangs

    Science.gov (United States)

    O'Loughlin, Martin; Seri, Lorenzo

    2010-07-01

    We study at the classical and quantum mechanical level the time-dependent Yang-Mills theory that one obtains via the generalisation of discrete light-cone quantization to singular homogeneous plane waves. The non-Abelian nature of this theory is known to be important for physics near the singularity, at least as far as the number of degrees of freedom is concerned. We will show that the quartic interaction is always subleading as one approaches the singularity and that close enough to t = 0 the evolution is driven by the diverging tachyonic mass term. The evolution towards asymptotically flat space-time also reveals some surprising features.

  7. Plasma instabilities and turbulence in non-Abelian gauge theories

    Energy Technology Data Exchange (ETDEWEB)

    Scheffler, Sebastian Herwig Juergen

    2010-02-17

    Several aspects of the thermalisation process in non-Abelian gauge theories are investigated. Both numerical simulations in the classical statistical approximation and analytical computations in the framework of the two-particle-irreducible effective action are carried out and their results are compared to each other. The physical quantities of central importance are the correlation functions of the gauge field in Coulomb and temporal axial gauge as well as the gauge invariant energy-momentum tensor. Following a general introduction, the theoretical framework of the ensuing investigations is outlined. In doing so, the range of validity of the employed approximation schemes is discussed as well. The first main part of the thesis is concerned with the early stage of the thermalisation process where particular emphasis is on the role of plasma instabilities. These investigations are relevant to the phenomenological understanding of present heavy ion collision experiments. First, an ensemble of initial conditions motivated by the ''colour glass condensate'' is developed which captures characteristic properties of the plasma created in heavy ion collisions. Here, the strong anisotropy and the large occupation numbers of low-momentum degrees of freedom are to be highlighted. Numerical calculations demonstrate the occurrence of two kinds of instabilities. Primary instabilities result from the specific initial conditions. Secondary instabilities are caused by nonlinear fluctuation effects of the preceding primary instabilities. The time scale associated with the instabilities is of order 1 fm/c. It is shown that the plasma instabilities isotropize the initially strongly anisotropic ensemble in the domain of low momenta (

  8. Plasma instabilities and turbulence in non-Abelian gauge theories

    International Nuclear Information System (INIS)

    Scheffler, Sebastian Herwig Juergen

    2010-01-01

    Several aspects of the thermalisation process in non-Abelian gauge theories are investigated. Both numerical simulations in the classical statistical approximation and analytical computations in the framework of the two-particle-irreducible effective action are carried out and their results are compared to each other. The physical quantities of central importance are the correlation functions of the gauge field in Coulomb and temporal axial gauge as well as the gauge invariant energy-momentum tensor. Following a general introduction, the theoretical framework of the ensuing investigations is outlined. In doing so, the range of validity of the employed approximation schemes is discussed as well. The first main part of the thesis is concerned with the early stage of the thermalisation process where particular emphasis is on the role of plasma instabilities. These investigations are relevant to the phenomenological understanding of present heavy ion collision experiments. First, an ensemble of initial conditions motivated by the ''colour glass condensate'' is developed which captures characteristic properties of the plasma created in heavy ion collisions. Here, the strong anisotropy and the large occupation numbers of low-momentum degrees of freedom are to be highlighted. Numerical calculations demonstrate the occurrence of two kinds of instabilities. Primary instabilities result from the specific initial conditions. Secondary instabilities are caused by nonlinear fluctuation effects of the preceding primary instabilities. The time scale associated with the instabilities is of order 1 fm/c. It is shown that the plasma instabilities isotropize the initially strongly anisotropic ensemble in the domain of low momenta (< or similar 1 GeV). Essential results can be translated from the gauge group SU(2) to SU(3) by a simple rescaling procedure. Finally, the role of Nielsen-Olesen instabilities in an idealised setup is investigated. In the second part, the quasi

  9. Gluon propagator in non-Abelian Weizsaecker-Williams fields

    International Nuclear Information System (INIS)

    Ayala, A.; Jalilian-Marian, J.; McLerran, L.; Venugopalan, R.

    1995-01-01

    We carefully compute the gluon propagator in the background of a non-Abelian Weizsaecker-Williams field. This background field is generated by the valence quarks in very large nuclei. We find contact terms in the small fluctuation equations of motion which induce corrections to a previously incorrect result for the gluon propagator in such a background field. The well-known problem of the Hermiticity of certain operators in the light cone gauge is resolved for the Weizsaecker-Williams background field. This is achieved by working in a gauge where singular terms in the equations of motion are absent and then gauge transforming the small fluctuation fields to the light cone gauge

  10. Majorana anyons, non-Abelian statistics and quantum computation in Chern-Simons-Higgs theory

    Science.gov (United States)

    Marino, E. C.; Brozeguini, J. C.

    2014-09-01

    We naturally obtain the NOT and CNOT logic gates, which are key pieces of quantum computing algorithms, in the framework of the non-Abelian Chern-Simons-Higgs theory in two spatial dimensions. For that, we consider the anyonic quantum vortex topological excitations and show that Majorana anyons, namely, self-adjoint combinations of these vortices and anti-vortices, have in general non-Abelian statistics. The associated unitary monodromy braiding matrices become the required logic gates in the special case when the vortex spin is s = 1/4, which corresponds to the case of Ising non-Abelian anyons, found in different quantum computing systems. We explicitly construct the vortex field operators, show that they carry both magnetic flux and charge and obtain their Euclidean correlation functions by using the method of quantization of topological excitations, which is based on the order-disorder duality. These correlators are in general multivalued, the number of sheets being determined by the vortex spin. This, by its turn, is proportional to the vacuum expectation value of the Higgs field and therefore can be tuned by both the free parameters of the Higgs potential and the temperature.

  11. On multifield Born and Born-Infeld theories and their non-Abelian generalizations

    Energy Technology Data Exchange (ETDEWEB)

    Cerchiai, Bianca L. [Museo Storico della Fisica e Centro Studi e Ricerche Enrico Fermi,P.zza del Viminale 1, I-00184 Roma (Italy); DISAT, Politecnico di Torino,Corso Duca degli Abruzzi 24, I-10129 Torino (Italy); Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Torino,via P. Giuria, 1, 20125 Torino (Italy); Trigiante, Mario [DISAT, Politecnico di Torino,Corso Duca degli Abruzzi 24, I-10129 Torino (Italy); Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Torino,via P. Giuria, 1, 20125 Torino (Italy)

    2016-10-28

    Starting from a recently proposed linear formulation in terms of auxiliary fields, we study n-field generalizations of Born and Born-Infeld theories. In this description the Lagrangian is quadratic in the vector field strengths and the symmetry properties (including the characteristic self-duality) of the corresponding non-linear theory are manifest as on-shell duality symmetries and depend on the choice of the (homogeneous) manifold spanned by the auxiliary scalar fields and the symplectic frame. By suitably choosing these defining properties of the quadratic Lagrangian, we are able to reproduce some known multi-field Born-Infeld theories and to derive new non-linear models, such as the n-field Born theory. We also discuss non-Abelian generalizations of these theories obtained by choosing the vector fields in the adjoint representation of an off-shell compact global symmetry group K and replacing them by non-Abelian, K-covariant field strengths, thus promoting K to a gauge group.

  12. New topological invariants for non-abelian antisymmetric tensor fields from extended BRS algebra

    International Nuclear Information System (INIS)

    Boukraa, S.; Maillet, J.M.; Nijhoff, F.

    1988-09-01

    Extended non-linear BRS and Gauge transformations containing Lie algebra cocycles, and acting on non-abelian antisymmetric tensor fields are constructed in the context of free differential algebras. New topological invariants are given in this framework. 6 refs

  13. Some novel features in 2D non-Abelian theory: BRST approach

    Science.gov (United States)

    Srinivas, N.; Kumar, S.; Kureel, B. K.; Malik, R. P.

    2017-08-01

    Within the framework of Becchi-Rouet-Stora-Tyutin (BRST) formalism, we discuss some novel features of a two (1+1)-dimensional (2D) non-Abelian 1-form gauge theory (without any interaction with matter fields). Besides the usual off-shell nilpotent and absolutely anticommutating (anti-)BRST symmetry transformations, we discuss the off-shell nilpotent and absolutely anticommutating (anti-)co-BRST symmetry transformations. Particularly, we lay emphasis on the existence of the coupled (but equivalent) Lagrangian densities of the 2D non-Abelian theory in view of the presence of (anti-)co-BRST symmetry transformations where we pin-point some novel features associated with the Curci-Ferrari (CF-)type restrictions. We demonstrate that these CF-type restrictions can be incorporated into the (anti-)co-BRST invariant Lagrangian densities through the fermionic Lagrange multipliers which carry specific ghost numbers. The modified versions of the Lagrangian densities (where we get rid of the new CF-type restrictions) respect some precise symmetries as well as a couple of symmetries with CF-type constraints. These observations are completely novel as far as the BRST formalism, with proper (anti-)co-BRST symmetries, is concerned.

  14. Critical non-Abelian vortex in four dimensions and little string theory

    Science.gov (United States)

    Shifman, M.; Yung, A.

    2017-08-01

    As was shown recently, non-Abelian vortex strings supported in four-dimensional N =2 supersymmetric QCD with the U(2) gauge group and Nf=4 quark multiplets (flavors) become critical superstrings. In addition to the translational moduli, non-Abelian strings under consideration carry six orientational and size moduli. Together, they form a ten-dimensional target space required for a superstring to be critical. The target space of the string sigma model is a product of the flat four-dimensional space and a Calabi-Yau noncompact threefold, namely, the conifold. We study closed string states which emerge in four dimensions and identify them with hadrons of four-dimensional N =2 QCD. One massless state was found previously; it emerges as a massless hypermultiplet associated with the deformation of the complex structure of the conifold. In this paper, we find a number of massive states. To this end, we exploit the approach used in LST little string theory, namely, the equivalence between the critical string on the conifold and noncritical c =1 string with the Liouville field and a compact scalar at the self-dual radius. The states we find carry "baryonic" charge (its definition differs from standard). We interpret them as "monopole necklaces" formed (at strong coupling) by the closed string with confined monopoles attached.

  15. Non-Abelian localization for supersymmetric Yang-Mills-Chern-Simons theories on a Seifert manifold

    Science.gov (United States)

    Ohta, Kazutoshi; Yoshida, Yutaka

    2012-11-01

    We derive non-Abelian localization formulas for supersymmetric Yang-Mills-Chern-Simons theory with matters on a Seifert manifold M, which is the three-dimensional space of a circle bundle over a two-dimensional Riemann surface Σ, by using the cohomological approach introduced by Källén. We find that the partition function and the vacuum expectation value of the supersymmetric Wilson loop reduces to a finite dimensional integral and summation over classical flux configurations labeled by discrete integers. We also find that the partition function reduces further to just a discrete sum over integers in some cases, and evaluate the supersymmetric index (Witten index) exactly on S1×Σ. The index completely agrees with the previous prediction from field theory and branes. We discuss a vacuum structure of the Aharony-Bergman-Jafferis-Maldacena theory deduced from the localization.

  16. On the confinement of monopoles in non-Abelian gauge theories

    International Nuclear Information System (INIS)

    Tsou, S.T.; Chan, H.-M.

    1981-03-01

    Monopoles in gauge theories, whether Abelian or non-Abelian, are characterised by the homotopy classes of closed circuits in their gauge group. It is shown that when the symmetry is spontaneously broken, they fall into two categories with respect to their confinement properties. 'Reducible' monopoles corresponding to homotopy classes which contain circuits lying entirely in the subgroup of the residual symmetry can exist isolated and free; otherwise they must be attached to energetic vortex lines. In particular, it is shown that whereas in completely broken symmetries, such as the Nielsen-Olesen SO(3) theory broken by two triplets of Higgs fields, all monopoles are permanently confined, in some partially broken symmetries including the Georgi-Glashow and Weinberg-Salam electroweak theories, monopoles are not confined. In these latter cases, the monopole flux need not be concentrated along vortex lines but can leak out in all directions via the components of the gauge potential corresponding to the residual symmetry. (author)

  17. Anisotopic inflation with a non-abelian gauge field in Gauss-Bonnet gravity

    International Nuclear Information System (INIS)

    Lahiri, Sayantani

    2017-01-01

    In presence of Gauss-Bonnet corrections, we study anisotropic inflation aided by a massless SU(2) gauge field where both the gauge field and the Gauss-Bonnet term are non-minimally coupled to the inflaton. In this scenario, under slow-roll approximations, the anisotropic inflation is realized as an attractor solution with quadratic forms of inflaton potential and Gauss-Bonnet coupling function. We show that the degree of anisotropy is proportional to the additive combination of two slow-roll parameters of the theory. The anisotropy may become either positive or negative similar to the non-Gauss-Bonnet framework, a feature of the model for anisotropic inflation supported by a non-abelian gauge field but the effect of Gauss-Bonnet term further enhances or suppresses the generated anisotropy.

  18. Renormalization and scaling behavior of non-Abelian gauge fields in curved spacetime

    International Nuclear Information System (INIS)

    Leen, T.K.

    1983-01-01

    In this article we discuss the one loop renormalization and scaling behavior of non-Abelian gauge field theories in a general curved spacetime. A generating functional is constructed which forms the basis for both the perturbation expansion and the Ward identifies. Local momentum space representations for the vector and ghost particles are developed and used to extract the divergent parts of Feynman integrals. The one loop diagram for the ghost propagator and the vector-ghost vertex are shown to have no divergences not present in Minkowski space. The Ward identities insure that this is true for the vector propagator as well. It is shown that the above renormalizations render the three- and four-vector vertices finite. Finally, a renormalization group equation valid in curved spacetimes is derived. Its solution is given and the theory is shown to be asymptotically free as in Minkowski space

  19. Parity violating superfluidity in ultra-cold atoms with artificial non-Abelian gauge fields

    Science.gov (United States)

    Han, Li; Seo, Kangjun; Sá de Melo, Carlos

    2013-04-01

    We discuss the creation of parity violating Fermi superfluids in the presence of non-Abelian gauge fields realized by artificial spin-orbit coupling and crossed Zeeman fields. Unlike the case in particle physics where the parity violation is driven by weak interaction, the parity breaking is due to the effects of non-Abelian gauge fields on the kinetic energy in our system. We analyze the signatures of parity violation on the excitation spectrum of the system in normal and superfluid phases, as well as ground state properties such as the spin-resolved momentum distribution, and excitation properties such as the spin-dependent spectral function and density of states.

  20. Nilpotent symmetries and Curci-Ferrari-type restrictions in 2D non-Abelian gauge theory: Superfield approach

    Science.gov (United States)

    Srinivas, N.; Malik, R. P.

    2017-11-01

    We derive the off-shell nilpotent symmetries of the two (1 + 1)-dimensional (2D) non-Abelian 1-form gauge theory by using the theoretical techniques of the geometrical superfield approach to Becchi-Rouet-Stora-Tyutin (BRST) formalism. For this purpose, we exploit the augmented version of superfield approach (AVSA) and derive theoretically useful nilpotent (anti-)BRST, (anti-)co-BRST symmetries and Curci-Ferrari (CF)-type restrictions for the self-interacting 2D non-Abelian 1-form gauge theory (where there is no interaction with matter fields). The derivation of the (anti-)co-BRST symmetries and all possible CF-type restrictions are completely novel results within the framework of AVSA to BRST formalism where the ordinary 2D non-Abelian theory is generalized onto an appropriately chosen (2, 2)-dimensional supermanifold. The latter is parametrized by the superspace coordinates ZM = (xμ,𝜃,𝜃¯) where xμ (with μ = 0, 1) are the bosonic coordinates and a pair of Grassmannian variables (𝜃,𝜃¯) obey the relationships: 𝜃2 = 𝜃¯2 = 0, 𝜃𝜃¯ + 𝜃¯𝜃 = 0. The topological nature of our 2D theory allows the existence of a tower of CF-type restrictions.

  1. q q ¯ Pair production in non-Abelian gauge fields

    Indian Academy of Sciences (India)

    Non-Abelian interactions in the colour field are time-dependent and hence should oscillate with a characteristic frequency 0 , which depends on the amplitude of the field strength. Using the WKB approximation in complex time, we calculated the pair production probability. When the strength of the field is comparable to the ...

  2. Quantum walks and non-Abelian discrete gauge theory

    Science.gov (United States)

    Arnault, Pablo; Di Molfetta, Giuseppe; Brachet, Marc; Debbasch, Fabrice

    2016-07-01

    A family of discrete-time quantum walks (DTQWs) on the line with an exact discrete U(N ) gauge invariance is introduced. It is shown that the continuous limit of these DTQWs, when it exists, coincides with the dynamics of a Dirac fermion coupled to usual U(N ) gauge fields in two-dimensional spacetime. A discrete generalization of the usual U(N ) curvature is also constructed. An alternate interpretation of these results in terms of superimposed U(1 ) Maxwell fields and SU(N ) gauge fields is discussed in the Appendix. Numerical simulations are also presented, which explore the convergence of the DTQWs towards their continuous limit and which also compare the DTQWs with classical (i.e., nonquantum) motions in classical SU(2 ) fields. The results presented in this paper constitute a first step towards quantum simulations of generic Yang-Mills gauge theories through DTQWs.

  3. Concerning Gribov vacuum copies in non-abelian gauge theory

    International Nuclear Information System (INIS)

    Frampton, P.H.; Palmer, W.F.; Pinsky, S.S.

    1978-01-01

    Construction of gauge field configurations A/sub μ//sup a/(x) in an SU(2) Yang-Mills theory satisfying everywhere F/sub μν//sup a/(x) = 0 is discussed. Using the method of sections, a field related to the zero-size limit of an instanton is presented. The corresponding limit for a multi-instanton solution requires a generalization of the Landau gauge condition. Finally, an alternative method and explicit solution is given for the case of delta/sub μ/A/sub μ//sup a/ = 0

  4. Electric-magnetic duality in non-Abelian gauge theories

    International Nuclear Information System (INIS)

    Mizrachi, L.

    1982-03-01

    The duality transformation of the vacuum expectation value of the operator which creates magnetic vortices (the 't Hooft loop operator in the Higgs phase) is performed in the radial gauge (xsub(μ)Asub(μ)sup(a)(x)=0). It is found that in the weak coupling region (small g) of a pure Yang-Mills theory the dual operator creates electric vortices whose strength is 1/g. The theory is self dual in this region, and the effective coupling of the dual Lagrangian is 1/g. Thus the above duality transformation reduces to electric-magnetic duality where the electric field in the 't Hooft loop operator transforms into a magnetic field in the dual operator. In a spontaneously broken gauge theory these results are valid only within the region where the vortices (or the monopoles) are concentrated, or in directions of the algebra space of unbroken symmetry, as self duality holds only for this subset of fields. In the strong coupling region a strong coupling expansion in powers of 1/g is suggested. (author)

  5. Dual computations of non-Abelian Yang-Mills theories on the lattice

    International Nuclear Information System (INIS)

    Cherrington, J. Wade; Khavkine, Igor; Christensen, J. Daniel

    2007-01-01

    In the past several decades there have been a number of proposals for computing with dual forms of non-Abelian Yang-Mills theories on the lattice. Motivated by the gauge-invariant, geometric picture offered by dual models and successful applications of duality in the U(1) case, we revisit the question of whether it is practical to perform numerical computation using non-Abelian dual models. Specifically, we consider three-dimensional SU(2) pure Yang-Mills as an accessible yet nontrivial case in which the gauge group is non-Abelian. Using methods developed recently in the context of spin foam quantum gravity, we derive an algorithm for efficiently computing the dual amplitude and describe Metropolis moves for sampling the dual ensemble. We relate our algorithms to prior work in non-Abelian dual computations of Hari Dass and his collaborators, addressing several problems that have been left open. We report results of spin expectation value computations over a range of lattice sizes and couplings that are in agreement with our conventional lattice computations. We conclude with an outlook on further development of dual methods and their application to problems of current interest

  6. q¯q Pair production in non-Abelian gauge fields

    Indian Academy of Sciences (India)

    August 2007 physics pp. 181–190 q¯q Pair production in non-Abelian gauge fields. S M PUZHAKKAL and V M BANNUR. Department of Physics, University of Calicut, Malappuram 673 635, India. E-mail: udayanandan km@rediffmail.com. MS received 4 November 2006; revised 1 April 2007; accepted 7 May 2007. Abstract.

  7. The hidden spatial geometry of non-Abelian gauge theories

    CERN Document Server

    Freedman, Daniel Z; Johnson, K; Latorre, J I

    1993-01-01

    The Gauss law constraint in the Hamiltonian form of the $SU(2)$ gauge theory of gluons is satisfied by any functional of the gauge invariant tensor variable $\\phi^{ij} = B^{ia} B^{ja}$. Arguments are given that the tensor $G_{ij} = (\\phi^{-1})_{ij}\\,\\det B$ is a more appropriate variable. When the Hamiltonian is expressed in terms of $\\phi$ or $G$, the quantity $\\Gamma^i_{jk}$ appears. The gauge field Bianchi and Ricci identities yield a set of partial differential equations for $\\Gamma$ in terms of $G$. One can show that $\\Gamma$ is a metric-compatible connection for $G$ with torsion, and that the curvature tensor of $\\Gamma$ is that of an Einstein space. A curious 3-dimensional spatial geometry thus underlies the gauge-invariant configuration space of the theory, although the Hamiltonian is not invariant under spatial coordinate transformations. Spatial derivative terms in the energy density are singular when $\\det G=\\det B=0$. These singularities are the analogue of the centrifugal barrier of quantum mecha...

  8. Classical glueballs in non-Abelian Born-Infeld theory.

    Science.gov (United States)

    Gal'tsov, D; Kerner, R

    2000-06-26

    It is shown that the Born-Infeld-type modification of the quadratic Yang-Mills action gives rise to classical particlelike solutions prohibited in the standard Yang-Mills theory. This becomes possible due to breaking of the scale invariance by the Born-Infeld nonlinearity. New classical glueballs, which are of a sphaleronic nature, exhibit a striking similarity to the Bartnik-McKinnon solutions to the Yang-Mills theory coupled to gravity.

  9. Non-Abelian sine-Gordon solitons

    Directory of Open Access Journals (Sweden)

    Muneto Nitta

    2015-06-01

    Full Text Available We point out that non-Abelian sine-Gordon solitons stably exist in the U(N chiral Lagrangian. They also exist in a U(N gauge theory with two N by N complex scalar fields coupled to each other. One non-Abelian sine-Gordon soliton can terminate on one non-Abelian global vortex. They are relevant in chiral Lagrangian of QCD or in color-flavor locked phase of high density QCD, where the anomaly is suppressed at asymptotically high temperature or density, respectively.

  10. Monopoles in non-Abelian Dirac-Born-Infeld theory

    International Nuclear Information System (INIS)

    Grandi, N.; Moreno, E.F.; Schaposnik, F.A.

    1999-01-01

    We investigate monopole solutions for the Born-Infeld Higgs system. We analyze numerically these solutions and compare them with the standard close-quote t Hooft - Polyakov monopoles. We also discuss the existence of a critical value of β (the Born-Infeld 'absolute field parameter') below which no regular solution exists. copyright 1999 The American Physical Society

  11. The existence of self-dual vortices in a non-Abelian Φ2 Chern-Simons theory

    International Nuclear Information System (INIS)

    Chen Shouxin; Wang Ying

    2010-01-01

    Applying the dynamic shooting method, we proved the existence of nontopological radially symmetric n-vortex solutions to the self-dual equation in non-Abelian Chern-Simons gauge theory with a Φ 2 -type potential. Moreover, we obtained all possible radially symmetric nontopological bare (or 0-vortex) solutions in the non-Abelian Chern-Simons model. Meanwhile, we established the asymptotic behavior for the solutions as |x|→∞.

  12. The gluon propagator in non-Abelian Weizsaecker-Williams fields

    International Nuclear Information System (INIS)

    Ayala, A.; Jalilian-Marian, J.; McLerran, L.; Venugopalan, R.

    1995-01-01

    The authors carefully compute the gluon propagator in the background of a non-Abelian Weizsaecker-Williams field. This background field is generated by the valence quarks in very large nuclei. They find contact terms in the small fluctuation equations of motion which induce corrections to a previously incorrect result for the gluon propagator in such a background field. The well known problem of the Hermiticity of certain operators in Light Cone gauge is resolved for the Weizsaecker-Williams background field. This is achieved by working in a gauge where singular terms in the equations of motion are absent and then gauge transforming the small fluctuation fields to Light Cone gauge

  13. Non-Abelian bosonization as a nonholonomic transformation from a flat to a curved field space

    Energy Technology Data Exchange (ETDEWEB)

    Kleinert, H. [Institut fuer Theoretische Physik, Freie Universitaet Berlin, Arnimallee 14, D-14195 Berlin (Germany)

    1997-01-01

    There exists a simple rule by which path integrals for the motion of a point particle in a flat space can be transformed correctly into those in a curved space. This rule arose from well-established methods in the theory of plastic deformations, where crystals with defects are described mathematically by applying active nonholonomic coordinate transformations to ideal crystals. In the context of time-sliced path integrals, this has given rise to a {ital quantum equivalence principle} which determines the short-time action and functional integration measure of fluctuating orbits in spaces with curvature and torsion. The nonholonomic transformations have a nontrivial Jacobian which in curved spaces produces an additional energy proportional to the curvature scalar, thereby canceling an equal term found earlier by DeWitt in his formulation of Feynman{close_quote}s time-sliced path integral in curved space. The importance of this cancelation has been documented in various systems (H-atom, particle on the surface of a sphere, spinning top). Here we point out its relevance to the bosonization of a non-Abelian one-dimensional quantum field theory, whose fields live in a flat field space. The bosonized version is a quantum-mechanical path integral of a point particle moving in a space with constant curvature. The additional term introduced by the Jacobian is crucial for the identity between original and bosonized theory. A useful bosonization tool is the so-called Hubbard{endash}Stratonovich formula for which we find a nonabelian version. {copyright} 1997 Academic Press, Inc.

  14. Non-Abelian bosonization as a nonholonomic transformation from a flat to a curved field space

    International Nuclear Information System (INIS)

    Kleinert, H.

    1997-01-01

    There exists a simple rule by which path integrals for the motion of a point particle in a flat space can be transformed correctly into those in a curved space. This rule arose from well-established methods in the theory of plastic deformations, where crystals with defects are described mathematically by applying active nonholonomic coordinate transformations to ideal crystals. In the context of time-sliced path integrals, this has given rise to a quantum equivalence principle which determines the short-time action and functional integration measure of fluctuating orbits in spaces with curvature and torsion. The nonholonomic transformations have a nontrivial Jacobian which in curved spaces produces an additional energy proportional to the curvature scalar, thereby canceling an equal term found earlier by DeWitt in his formulation of Feynman close-quote s time-sliced path integral in curved space. The importance of this cancelation has been documented in various systems (H-atom, particle on the surface of a sphere, spinning top). Here we point out its relevance to the bosonization of a non-Abelian one-dimensional quantum field theory, whose fields live in a flat field space. The bosonized version is a quantum-mechanical path integral of a point particle moving in a space with constant curvature. The additional term introduced by the Jacobian is crucial for the identity between original and bosonized theory. A useful bosonization tool is the so-called Hubbard endash Stratonovich formula for which we find a nonabelian version. copyright 1997 Academic Press, Inc

  15. On the loop-loop scattering amplitudes in Abelian and non-Abelian gauge theories

    Energy Technology Data Exchange (ETDEWEB)

    Meggiolaro, Enrico [Dipartimento di Fisica, Universita di Pisa, Largo Pontecorvo 3, I-56127 Pisa (Italy)]. E-mail: enrico.meggiolaro@df.unipi.it

    2005-02-14

    The high-energy elastic scattering amplitude of two colour-singlet qq-bar pairs is governed by the correlation function of two Wilson loops, which follow the classical straight lines for quark (antiquark) trajectories. This quantity is expected to be free of IR divergences, differently from what happens for the parton-parton elastic scattering amplitude, described, in the high-energy limit, by the expectation value of two Wilson lines. We shall explicitly test this IR finiteness by a direct non-perturbative computation of the loop-loop scattering amplitudes in the (pedagogic, but surely physically interesting) case of quenched QED. The results obtained for the Abelian case will be generalized to the case of a non-Abelian gauge theory with Nc colours, but stopping to the order O(g4) in perturbation theory. In connection with the above-mentioned IR finiteness, we shall also discuss some analytic properties of the loop-loop scattering amplitudes in both Abelian and non-Abelian gauge theories, when going from Minkowskian to Euclidean theory, which can be relevant to the still unsolved problem of the s-dependence of hadron-hadron total cross-sections.

  16. The valley method and its application to the instanton-induced phenomena in non-abelian gauge theories

    International Nuclear Information System (INIS)

    Khoze, V.V.

    1991-06-01

    The semiclassical evaluation of the functional integral on non-Abelian gauge theories is generalized by means of the so-called valley method. The physically very important example of the valley, the instanton-anti-instanton field configuration, is discussed in details and its contributions to the physical quantities for zero-temperature and for thermal field theories are investigated. The high-energy behaviour of the total cross-section σ Δ F for electroweak fermion number violating two particles collisions is studied using the optical theorem approach. The calculation is done at energies below the sphaleron mass (E<10TeV) where it leads to the most complete result for σ Δ F known to date. Some estimations and a qualitative physical picture are discussed for energies above the sphaleron mass for the confinement and Higgs phases of the gauge theory. The effects of instanton-anti-instanton interactions are also studied in thermal QCD. (au)

  17. Fixed points in perturbative non-Abelian four-Fermi theory in (3+1)D

    Energy Technology Data Exchange (ETDEWEB)

    Alves, Van Sérgio, E-mail: vansergi@ufpa.br [Faculdade de Física, Universidade Federal do Pará, 66075-110, Belém, PA (Brazil); Nascimento, Leonardo, E-mail: lnascimento@ufpa.br [Faculdade de Física, Universidade Federal do Pará, 66075-110, Belém, PA (Brazil); Peña, Francisco, E-mail: francisco.pena@ufrontera.cl [Departamento de Ciencias Físicas, Facultad de Ingeniería, Ciencias y Administración, Universidad de La Frontera, Avda. Francisco Salazar 01145, Casilla 54-D, Temuco (Chile)

    2013-12-09

    We analyze the structure of fixed points for the non-Abelian four-fermion interactions model in (3+1) dimensions, which has SU(N{sub c})⊗SU(N{sub f}){sub L}⊗SU(N{sub f}){sub R} symmetry from the perturbative calculation of the beta function of the reduced system. We treat the model as an effective theory valid in a scale of energy on which p≪M, where p are the external momenta and M is a massive parameter that characterizes the coupling constants. Using the Zimmermann reduction mechanism, we show up to 1-loop order, that beyond the infrared fixed point at the origin there is a line of non-trivial ultraviolet fixed points that depend on N{sub c} and N{sub f}.

  18. Theoretical physics 3. Classical field theory. On electrodynamics, non-Abelian gauge theories, and gravitation. 4. ed.; Theoretische Physik 3. Klassische Feldtheorie. Von Elektrodynamik, nicht-Abelschen Eichtheorien und Gravitation

    Energy Technology Data Exchange (ETDEWEB)

    Scheck, Florian [Mainz Univ. (Germany). Inst. fuer Physik

    2017-09-01

    The following topics are dealt with: Maxwell's equations together with their symmetry and covariance, the Maxwell theory as classical field theory, simple applications of Maxwell's theory, local gauge theories, classical field theory of gravitation. (HSI)

  19. Zk string fluxes and monopole confinement in non-Abelian theories

    International Nuclear Information System (INIS)

    Kneipp, Marco A.C.; Centro Brasileiro de Pesquisas Fisicas

    2002-11-01

    Recently we considered N = 2 Super Yang-Mills with a mass breaking term and showed the existence of BPS Z k -string solutions for arbitrary simple gauge groups which are spontaneously broken to non-Abelian residual gauge groups. We also calculated their string tensions exactly. In doing so, we have considered in particular the hyper multiplet in the representation of a diquark condensate. In the present work we shall analyze some of the different phases of the theory and find that the magnetic fluxes of the monopoles and Z k strings of the theory are proportional to one another, allowing for monopole confinement in one of the phase transitions of the theory. Then we will calculate the threshold length for a string to break in a new pair of monopole-anti monopole. We will further show that some of the resulting confining theories can obtained by adding a deformation term to N 2 or N = 4 superconformal theories and, as such, may satisfy a gauge/string correspondence. (author)

  20. Non-Abelian phenomena on D-branes

    CERN Document Server

    Myers, R

    2003-01-01

    A remarkable feature of D-branes is the appearance of a non-Abelian gauge theory in the description of several (nearly) coincident branes. This non-Abelian structure plays an important role in realizing various geometric effects with D-branes. In particular, the branes' transverse displacements are described by matrix-valued scalar fields and so noncommutative geometry naturally appears in this framework. I review the action governing this non-Abelian theory, as well as various related physical phenomena such as the dielectric effect, giant gravitons and fuzzy funnels.

  1. Type II string theory on Calabi-Yau manifolds with torsion and non-Abelian discrete gauge symmetries

    Science.gov (United States)

    Braun, Volker; Cvetič, Mirjam; Donagi, Ron; Poretschkin, Maximilian

    2017-07-01

    We provide the first explicit example of Type IIB string theory compactification on a globally defined Calabi-Yau threefold with torsion which results in a four-dimensional effective theory with a non-Abelian discrete gauge symmetry. Our example is based on a particular Calabi-Yau manifold, the quotient of a product of three elliptic curves by a fixed point free action of Z_2× Z_2 . Its cohomology contains torsion classes in various degrees. The main technical novelty is in determining the multiplicative structure of the (torsion part of) the cohomology ring, and in particular showing that the cup product of second cohomology torsion elements goes non-trivially to the fourth cohomology. This specifies a non-Abelian, Heisenberg-type discrete symmetry group of the cfour-dimensional theory.

  2. Quark confinement: Dual superconductor picture based on a non-Abelian Stokes theorem and reformulations of Yang-Mills theory

    Science.gov (United States)

    Kondo, Kei-Ichi; Kato, Seikou; Shibata, Akihiro; Shinohara, Toru

    2015-05-01

    The purpose of this paper is to review the recent progress in understanding quark confinement. The emphasis of this review is placed on how to obtain a manifestly gauge-independent picture for quark confinement supporting the dual superconductivity in the Yang-Mills theory, which should be compared with the Abelian projection proposed by 't Hooft. The basic tools are novel reformulations of the Yang-Mills theory based on change of variables extending the decomposition of the SU(N) Yang-Mills field due to Cho, Duan-Ge and Faddeev-Niemi, together with the combined use of extended versions of the Diakonov-Petrov version of the non-Abelian Stokes theorem for the SU(N) Wilson loop operator. Moreover, we give the lattice gauge theoretical versions of the reformulation of the Yang-Mills theory which enables us to perform the numerical simulations on the lattice. In fact, we present some numerical evidences for supporting the dual superconductivity for quark confinement. The numerical simulations include the derivation of the linear potential for static interquark potential, i.e., non-vanishing string tension, in which the "Abelian" dominance and magnetic monopole dominance are established, confirmation of the dual Meissner effect by measuring the chromoelectric flux tube between quark-antiquark pair, the induced magnetic-monopole current, and the type of dual superconductivity, etc. In addition, we give a direct connection between the topological configuration of the Yang-Mills field such as instantons/merons and the magnetic monopole. We show especially that magnetic monopoles in the Yang-Mills theory can be constructed in a manifestly gauge-invariant way starting from the gauge-invariant Wilson loop operator and thereby the contribution from the magnetic monopoles can be extracted from the Wilson loop in a gauge-invariant way through the non-Abelian Stokes theorem for the Wilson loop operator, which is a prerequisite for exhibiting magnetic monopole dominance for quark

  3. Cavity Optomechanics with Ultra Cold Atoms in Synthetic Abelian and Non-Abelian Gauge Field

    Directory of Open Access Journals (Sweden)

    Bikash Padhi

    2015-12-01

    Full Text Available In this article we present a pedagogical discussion of some of the optomechanical properties of a high finesse cavity loaded with ultracold atoms in laser induced synthetic gauge fields of different types. Essentially, the subject matter of this article is an amalgam of two sub-fields of atomic molecular and optical (AMO physics namely, the cavity optomechanics with ultracold atoms and ultracold atoms in synthetic gauge field. After providing a brief introduction to either of these fields we shall show how and what properties of these trapped ultracold atoms can be studied by looking at the cavity (optomechanical or transmission spectrum. In presence of abelian synthetic gauge field we discuss the cold-atom analogue of Shubnikov de Haas oscillation and its detection through cavity spectrum. Then, in the presence of a non-abelian synthetic gauge field (spin-orbit coupling, we see when the electromagnetic field inside the cavity is quantized, it provides a quantum optical lattice for the atoms, leading to the formation of different quantum magnetic phases. We also discuss how these phases can be explored by studying the cavity transmission spectrum.

  4. A note on the fate of the Landau–Yang theorem in non-Abelian gauge theories

    CERN Document Server

    Cacciari, Matteo; Espinosa, José R.; Polosa, Antonio D.; Testa, Massimo

    2016-01-01

    Using elementary considerations of Lorentz invariance, Bose symmetry and BRST invariance, we argue why the decay of a massive color-octet vector state into a pair of on-shell massless gluons is possible in a non-Abelian SU(N) Yang-Mills theory, we constrain the form of the amplitude of the process and offer a simple understanding of these results in terms of effective-action operators.

  5. A note on the fate of the Landau–Yang theorem in non-Abelian gauge theories

    Directory of Open Access Journals (Sweden)

    Matteo Cacciari

    2016-02-01

    Full Text Available Using elementary considerations of Lorentz invariance, Bose symmetry and BRST invariance, we argue why the decay of a massive color-octet vector state into a pair of on-shell massless gluons is possible in a non-Abelian SU(N Yang–Mills theory, we constrain the form of the amplitude of the process and offer a simple understanding of these results in terms of effective-action operators.

  6. A solenoidal synthetic field and the non-Abelian Aharonov-Bohm effects in neutral atoms

    Science.gov (United States)

    Huo, Ming-Xia; Nie, Wei; Hutchinson, David A. W.; Kwek, Leong Chuan

    2014-08-01

    Cold neutral atoms provide a versatile and controllable platform for emulating various quantum systems. Despite efforts to develop artificial gauge fields in these systems, realizing a unique ideal-solenoid-shaped magnetic field within the quantum domain in any real-world physical system remains elusive. Here we propose a scheme to generate a ``hairline'' solenoid with an extremely small size around 1 micrometer which is smaller than the typical coherence length in cold atoms. Correspondingly, interference effects will play a role in transport. Despite the small size, the magnetic flux imposed on the atoms is very large thanks to the very strong field generated inside the solenoid. By arranging different sets of Laguerre-Gauss (LG) lasers, the generation of Abelian and non-Abelian SU(2) lattice gauge fields is proposed for neutral atoms in ring- and square-shaped optical lattices. As an application, interference patterns of the magnetic type-I Aharonov-Bohm (AB) effect are obtained by evolving atoms along a circle over several tens of lattice cells. During the evolution, the quantum coherence is maintained and the atoms are exposed to a large magnetic flux. The scheme requires only standard optical access, and is robust to weak particle interactions.

  7. A solenoidal synthetic field and the non-Abelian Aharonov-Bohm effects in neutral atoms.

    Science.gov (United States)

    Huo, Ming-Xia; Nie, Wei; Hutchinson, David A W; Kwek, Leong Chuan

    2014-08-08

    Cold neutral atoms provide a versatile and controllable platform for emulating various quantum systems. Despite efforts to develop artificial gauge fields in these systems, realizing a unique ideal-solenoid-shaped magnetic field within the quantum domain in any real-world physical system remains elusive. Here we propose a scheme to generate a "hairline" solenoid with an extremely small size around 1 micrometer which is smaller than the typical coherence length in cold atoms. Correspondingly, interference effects will play a role in transport. Despite the small size, the magnetic flux imposed on the atoms is very large thanks to the very strong field generated inside the solenoid. By arranging different sets of Laguerre-Gauss (LG) lasers, the generation of Abelian and non-Abelian SU(2) lattice gauge fields is proposed for neutral atoms in ring- and square-shaped optical lattices. As an application, interference patterns of the magnetic type-I Aharonov-Bohm (AB) effect are obtained by evolving atoms along a circle over several tens of lattice cells. During the evolution, the quantum coherence is maintained and the atoms are exposed to a large magnetic flux. The scheme requires only standard optical access, and is robust to weak particle interactions.

  8. Non-Abelian T-duality for nonrelativistic holographic duals

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Thiago R.; Nastase, Horatiu [Instituto de Física Teórica, UNESP-Universidade Estadual Paulista,R. Dr. Bento T. Ferraz 271, Bl. II, Sao Paulo 01140-070, SP (Brazil)

    2015-11-30

    We find new type II backgrounds with non-relativistic symmetries via non-Abelian T-duality. First we consider geometries with Galilean symmetries in type IIA, which have been identified as non-relativistic generalizations of the ABJM background and massive IIA supergravities. We then consider the non-Abelian T-duality transformation on the backgrounds with Lifshitz symmetry constructed by Donos and Gauntlett. Using gauge/gravity duality we study aspects of the field theory dual to these backgrounds.

  9. Dependence of the Gauss-law constraints on the regularization scheme in non-Abelian chiral gauge theory

    International Nuclear Information System (INIS)

    Zhou, J.; Li, S.; Liu, Y.

    1993-01-01

    Mitra's regularization of the masslike term, which was originally discussed in an Abelian model, is used to calculate the anomaly in the commutator of the Gauss-law operators for anomalous d=2 non-Abelian chiral theory. The Schwinger term in the commutator of the different Gauss-law operator is shifted, because of regularization ambiguities, to the commutator of the Gauss-law operators with themselves. The Poisson brackets of the Gauss-law constraints correspond to the Kac-Moody algebra, and the Gauss-law constraints are similar to the chiral constraints. In a sense, this kind of Gauss-law constraint structure differs from what Faddeev suggested

  10. Relativistic longitudinal non-Abelian oscillations in quark–antiquark ...

    Indian Academy of Sciences (India)

    such attempt was done by Bhat et al [1] using non-relativistic fluid equations and SU(2) gauge theory. They found a new non-Abelian oscillation, in addition to the normal Abelian oscillations for the weak non-Abelian coupling. These two modes repeat alternatively with time as the system evolve. For the strong non-Abelian ...

  11. Finite temperature formalism for non-Abelian gauge theories in the physical phase space

    Science.gov (United States)

    Nachbagauer, Herbert

    1995-09-01

    We establish a new framework of finite temperature field theory for Yang-Mills theories in the physical phase space eliminating all unphysical degrees of freedom. Relating our method to the imaginary time formalism of James and Landshoff in the temporal axial gauge, we calculate the two-loop pressure and provide a systematic and unique method to construct the additional vertices encountered in their approach.

  12. Finite temperature formalism for non-Abelian gauge theories in the physical phase space

    Energy Technology Data Exchange (ETDEWEB)

    Nachbagauer, H. [Laboratoire de Physique Theorique ENSLAPP, Chemin de Bellevue, BP 110, F-74941 Annecy-le-Vieux Cedex (France)

    1995-09-15

    We establish a new framework of finite temperature field theory for Yang-Mills theories in the physical phase space eliminating all unphysical degrees of freedom. Relating our method to the imaginary time formalism of James and Landshoff in the temporal axial gauge, we calculate the two-loop pressure and provide a systematic and unique method to construct the additional vertices encountered in their approach.

  13. Topological insulators in cold-atom gases with non-Abelian gauge fields: the role of interactions

    Energy Technology Data Exchange (ETDEWEB)

    Orth, Peter Philipp [Institut fuer Theorie der Kondensierten Materie, Karlsruher Institut fuer Technologie, 76128 Karlsruhe (Germany); Cocks, Daniel; Buchhold, Michael; Hofstetter, Walter [Institut fuer Theoretische Physik, Goethe Universitaet, 60438 Frankfurt am Main (Germany); Rachel, Stephan [Department of Physics, Yale University, New Haven, Connecticut 06520 (United States); Le Hur, Karyn [Department of Physics, Yale University, New Haven, Connecticut 06520 (United States); Center for Theoretical Physics, Ecole Polytechnique, 91128 Palaiseau Cedex (France)

    2012-07-01

    With the recent technological advance of creating (non)-Abelian gauge fields for ultracold atoms in optical lattices, it becomes possible to study the interplay of topological phases and interactions in these systems. Specifically, we consider a spinful and time-reversal invariant version of the Hofstadter problem. In addition, we allow for a hopping term which does not preserve S{sub z} spin symmetry and a staggered sublattice potential. Without interactions, the parameters can be tuned such that the system is a topological insulator. Using a combination of analytical techniques and the powerful real-space dynamical mean-field (R-DMFT) method, we discuss the effect of interactions and determine the interacting phase diagram.

  14. Approach to solve Slavnov-Taylor identities in nonsupersymmetric non-Abelian gauge theories

    International Nuclear Information System (INIS)

    Kondrashuk, Igor; Cvetic, Gorazd; Schmidt, Ivan

    2003-01-01

    We present a way to solve Slavnov-Taylor identities in a general nonsupersymmetric theory. The solution can be parametrized by a limited number of functions of spacetime coordinates, so that all the effective fields are dressed by these functions via integral convolution. The solution restricts the ghost part of the effective action and gives predictions for the physical part of the effective action

  15. Mesons from (non) Abelian T-dual backgrounds

    Energy Technology Data Exchange (ETDEWEB)

    Itsios, Georgios [Instituto de Física Teórica, UNESP-Universidade Estadual Paulista, R. Dr. Bento T. Ferraz 271, Bl. II, Sao Paulo 01140-070, SP (Brazil); Department of Physics, University of Oviedo,Avda. Calvo Sotelo 18, 33007 Oviedo (Spain); Núñez, Carlos [Department of Physics, Swansea University,Swansea SA2 8PP (United Kingdom); Zoakos, Dimitrios [Centro de Física do Porto, Universidade do Porto,Rua do Campo Alegre 687, 4169-007 Porto (Portugal)

    2017-01-03

    In this work we study mesonic excitations in a Quantum Field Theory dual to the non Abelian T-dual of AdS{sub 5}×S{sup 5}, using a D6 brane probe on the Sfetsos-Thompson background. Before and after the duality, we observe interesting differences between the spectra and interpret them. The spectrum of masses and the interactions between mesonic excitations teach valuable lessons about the character of non-Abelian T-duality and its implications for Holography. The case of Abelian T-duality is also studied.

  16. Classifying bions in Grassmann sigma models and non-Abelian gauge theories by D-branes

    Science.gov (United States)

    Misumi, Tatsuhiro; Nitta, Muneto; Sakai, Norisuke

    2015-03-01

    We classify bions in the Grassmann Gr_{N_F,N_C} sigma model (including the {C}P^{N_F-1} model) on {R}1× S1 with twisted boundary conditions. We formulate these models as U(N_C) gauge theories with N_F flavors in the fundamental representations. These theories can be promoted to supersymmetric gauge theories and, further, can be embedded into D-brane configurations in type-II superstring theories. We focus on specific configurations composed of multiple fractional instantons, termed neutral bions and charged bions, which are identified as perturbative infrared renormalons by Ünsal and his collaborators [G. V. Dunne and M. Ünsal, J. High Energy Phys. 1211, 170 (2012); G. V. Dunne and M. Ünsal, Phys. Rev. D 87, 025015 (2013)]. We show that D-brane configurations, as well as the moduli matrix, offer a very useful tool to classify all possible bion configurations in these models. In contrast to the {C}P^{N_F-1} model, there exist Bogomol'nyi-Prasad-Sommerfield (BPS) fractional instantons with topological charges greater than unity (of order N_C) that cannot be reduced to a composite of an instanton and fractional instantons. As a consequence, we find that the Grassmann sigma model admits neutral bions made of BPS and anti-BPS fractional instantons, each of which has a topological charge greater (less) than one (minus one), that are not decomposable into an instanton-anti-instanton pair and the rest. The {C}P^{N_F-1} model is found to have no charged bions. In contrast, we find that the Grassmann sigma model admits charged bions, for which we construct exact non-BPS solutions of the field equations.

  17. On the elimination of infinitesimal Gribov ambiguities in non-Abelian gauge theories

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Antonio D.; Sobreiro, Rodrigo F. [UFF - Universidade Federal Fluminense, Instituto de Fisica, Campus da Praia Vermelha, Niteroi, RJ (Brazil)

    2013-10-15

    An alternative method to account for the Gribov ambiguities in gauge theories is presented. It is shown that, to eliminate Gribov ambiguities, at infinitesimal level, it is required to break the BRST symmetry in a soft manner. This can be done by introducing a suitable extra constraint that eliminates the infinitesimal Gribov copies. It is shown that the present approach is consistent with the well established known cases in the literature, i.e., the Landau and maximal Abelian gauges. The method is valid for gauges depending exclusively on the gauge field and is restricted to classical level. However, occasionally, we deal with quantum aspects of the technique, which are used to improve the results. (orig.)

  18. Consistent quantization of a two-dimensional non-abelian chiral theory

    Energy Technology Data Exchange (ETDEWEB)

    Manias, V.M.; Schaposnik, F.A.; Trobo, M.

    1987-09-03

    A two-dimensional SU(N) gauge model coupled to Weyl fermions is studied following recent suggestions for the quantization of potentially anomalous chiral theories. The Weyl fermion determinant is evaluated and the fermionic current is shown to be conserved due to the gauge invariance of the resulting quantum theory. As in the abelian case, the vector meson acquires a mass and the model is consistent provided a regularization parameter is conveniently chosen.

  19. Atomic Quantum Simulations of Abelian and non-Abelian Gauge Theories

    CERN Multimedia

    CERN. Geneva

    2014-01-01

    Using a Fermi-Bose mixture of ultra-cold atoms in an optical lattice, in a collaboration of atomic and particle physicists, we have constructed a quantum simulator for a U(1) gauge theory coupled to fermionic matter. The construction is based on quantum link models which realize continuous gauge symmetry with discrete quantum variables. At low energies, quantum link models with staggered fermions emerge from a Hubbard-type model which can be quantum simulated. This allows investigations of string breaking as well as the real-time evolution after a quench in gauge theories, which are inaccessible to classical simulation methods. Similarly, using ultracold alkaline-earth atoms in optical lattices, we have constructed a quantum simulator for U(N) and SU(N) lattice gauge theories with fermionic matter based on quantum link models. These systems share qualitative features with QCD, including chiral symmetry breaking and restoration at non-zero temperature or baryon density. Unlike classical simulations, a quantum ...

  20. Stable Non-Abelian Semi-Superfluid Vortices in Dense QCD

    Science.gov (United States)

    Chatterjee, Chandrasekhar; Nitta, Muneto

    Color superconductivity is expected to be formed in high density quark matter where color symmetry is spontaneously broken in the presence of di-quark condensate. Stable non-Abelian vortices or color magnetic flux tubes exist in the color-flavor locked phase at asymptotically high density. CP2 Nambu-Goldstone (NG) bosons and Majorana fermions belonging to the triplet representation are localized around a non-Abelian vortex. We discuss the zero mode analysis and the low-energy effective world sheet theory of a non-Abelian vortex. We determine the interactions of these bosonic and fermionic modes by using the nonlinear realization method. We also discuss the Aharanov-Bohm (AB) phases of charged particles, such as, electrons, muons, and color-flavor locked mesons made of tetra-quarks encircling around a non-Abelian vortex in the presence of electro-magnetic fields. This is a review based on our recent works [1-3].

  1. Colored, spinning classical particle in an external non-Abelian gauge field

    International Nuclear Information System (INIS)

    Arodz, H.

    1982-04-01

    Classical non-relativistic equations of motion are derived for a colored, spinning point-like particle in an external SU(2) gauge field from Dirac equation. It is found that in addition to the classical spin and color spin vectors, S, I, it is necessary to introduce a new classical dynamical variable [Jsup(ab)], a,b = 1,2,3, describing a mixing of the spin and color. The constraint relations between [Jsup(ab)], S, I are also found. (Auth.)

  2. Topological insulating phases of non-Abelian anyonic chains

    Energy Technology Data Exchange (ETDEWEB)

    DeGottardi, Wade

    2014-08-01

    Boundary conformal field theory is brought to bear on the study of topological insulating phases of non- Abelian anyonic chains. These phases display protected anyonic end modes. We consider spin-1/2 su(2)t chains at any level k, focusing on the most prominent examples: the case k = 2 describes Ising anyons (equivalent to Majorana fermions) and k = 3 corresponds to Fibonacci anyons. The method we develop is quite general and rests on a deep connection between boundary conformal field theory and topological symmetry. This method tightly constrains the nature of the topological insulating phases of these chains for general k. Emergent anyons which arise at domain walls are shown to have the same braiding properties as the physical quasiparticles. This suggests a "solid-stat.e" topological quantum computation scheme in which emergent anyons are braided by tuning the couplings of non-Abelian quasiparticles in a fixed network.

  3. Non Abelian T-duality in Gauged Linear Sigma Models

    Science.gov (United States)

    Bizet, Nana Cabo; Martínez-Merino, Aldo; Zayas, Leopoldo A. Pando; Santos-Silva, Roberto

    2018-04-01

    Abelian T-duality in Gauged Linear Sigma Models (GLSM) forms the basis of the physical understanding of Mirror Symmetry as presented by Hori and Vafa. We consider an alternative formulation of Abelian T-duality on GLSM's as a gauging of a global U(1) symmetry with the addition of appropriate Lagrange multipliers. For GLSMs with Abelian gauge groups and without superpotential we reproduce the dual models introduced by Hori and Vafa. We extend the construction to formulate non-Abelian T-duality on GLSMs with global non-Abelian symmetries. The equations of motion that lead to the dual model are obtained for a general group, they depend in general on semi-chiral superfields; for cases such as SU(2) they depend on twisted chiral superfields. We solve the equations of motion for an SU(2) gauged group with a choice of a particular Lie algebra direction of the vector superfield. This direction covers a non-Abelian sector that can be described by a family of Abelian dualities. The dual model Lagrangian depends on twisted chiral superfields and a twisted superpotential is generated. We explore some non-perturbative aspects by making an Ansatz for the instanton corrections in the dual theories. We verify that the effective potential for the U(1) field strength in a fixed configuration on the original theory matches the one of the dual theory. Imposing restrictions on the vector superfield, more general non-Abelian dual models are obtained. We analyze the dual models via the geometry of their susy vacua.

  4. Non-Abelian anyons: when Ising meets Fibonacci

    NARCIS (Netherlands)

    Grosfeld, E.; Schoutens, K.

    2009-01-01

    We consider an interface between two non-Abelian quantum Hall states: the Moore-Read state, supporting Ising anyons, and the k=2 non-Abelian spin-singlet state, supporting Fibonacci anyons. It is shown that the interface supports neutral excitations described by a (1+1)-dimensional conformal field

  5. Topological Quantum Phase Transition in Synthetic Non-Abelian Gauge Potential: Gauge Invariance and Experimental Detections

    Science.gov (United States)

    Sun, Fadi; Yu, Xiao-Lu; Ye, Jinwu; Fan, Heng; Liu, Wu-Ming

    2013-01-01

    The method of synthetic gauge potentials opens up a new avenue for our understanding and discovering novel quantum states of matter. We investigate the topological quantum phase transition of Fermi gases trapped in a honeycomb lattice in the presence of a synthetic non-Abelian gauge potential. We develop a systematic fermionic effective field theory to describe a topological quantum phase transition tuned by the non-Abelian gauge potential and explore its various important experimental consequences. Numerical calculations on lattice scales are performed to compare with the results achieved by the fermionic effective field theory. Several possible experimental detection methods of topological quantum phase transition are proposed. In contrast to condensed matter experiments where only gauge invariant quantities can be measured, both gauge invariant and non-gauge invariant quantities can be measured by experimentally generating various non-Abelian gauges corresponding to the same set of Wilson loops. PMID:23846153

  6. Non-abelian action for multiple five-branes with self-dual tensors

    Science.gov (United States)

    Chu, Chong-Sun; Ko, Sheng-Lan

    2012-05-01

    We construct an action for non-abelian 2-form in 6-dimensions. Our action consists of a non-abelian generalization of the abelian action of Perry and Schwarz for a single five-brane. It admits a self-duality equation on the field strength as the equation of motion. It has a modified 6d Lorentz symmetry. On dimensional reduction on a circle, our action gives the standard 5d Yang-Mills action plus higher order corrections. Based on these properties, we propose that our theory describes the gauge sector of multiple M5-branes in flat space.

  7. A non-Abelian black ring

    Directory of Open Access Journals (Sweden)

    Tomás Ortín

    2016-09-01

    Full Text Available We construct a supersymmetric black ring solution of SU(2 N=1, d=5 Super-Einstein–Yang–Mills (SEYM theory by adding a distorted BPST instanton to an Abelian black ring solution of the same theory. The change cannot be observed from spatial infinity: neither the mass, nor the angular momenta or the values of the scalars at infinity differ from those of the Abelian ring. The entropy is, however, sensitive to the presence of the non-Abelian instanton, and it is smaller than that of the Abelian ring, in analogy to what happens in the supersymmetric colored black holes recently constructed in the same theory and in N=2, d=4 SEYM. By taking the limit in which the two angular momenta become equal we derive a non-Abelian generalization of the BMPV rotating black-hole solution.

  8. Field theory

    CERN Multimedia

    1999-11-08

    In these lectures I will build up the concept of field theory using the language of Feynman diagrams. As a starting point, field theory in zero spacetime dimensions is used as a vehicle to develop all the necessary techniques: path integral, Feynman diagrams, Schwinger-Dyson equations, asymptotic series, effective action, renormalization etc. The theory is then extended to more dimensions, with emphasis on the combinatorial aspects of the diagrams rather than their particular mathematical structure. The concept of unitarity is used to, finally, arrive at the various Feynman rules in an actual, four-dimensional theory. The concept of gauge-invariance is developed, and the structure of a non-abelian gauge theory is discussed, again on the level of Feynman diagrams and Feynman rules.

  9. Semiclassical strings and non-Abelian T-duality

    Directory of Open Access Journals (Sweden)

    S. Zacarías

    2014-10-01

    Full Text Available We study semiclassical strings in the Klebanov–Witten and in the non-Abelian T-dual Klebanov–Witten backgrounds. We show that both backgrounds share a subsector of equivalent states up to conditions on the T-dual coordinates. We also analyse string configurations where the strings are stretched along the T-dual coordinates. This semiclassical analysis predicts the existence of (almost chiral primary operators for the dual superconformal field theory whose (anomalous bare dimensions depend on the T-dual coordinates. We briefly discuss the Penrose limit of the dualised background.

  10. Supersymmetric non-Abelian gauge models; the exact β-function from one loop of perturbation theory

    International Nuclear Information System (INIS)

    Vainshtein, A.I.; Zakharov, V.I.; Shifman, M.A.

    1986-01-01

    A method for calculating the exact β-function (in all orders in the coupling constant), proposed earlier in supersymmetric electrodynamics, is generalized. The starting point is the observation that the low-energy effective action is exhausted by one loop, provided that the theory is supersymmetrically regularized both in the ultraviolet and in the infrared region in four dimensions. For the ultraviolet regularization the Pauli-Villars method is used, while for the infrared regularization two variants are considered. The first: quantization in a box of finite volume L 3 : is universally applicable to any gauge theory. The second variant is based on an effective Higgs mechanism for generation of mass, and requires the presence of certain matter superfields in the Lagrangian. For the second method a necessary condition is the existence of flat directions: so-called valleys along which the energy of the vacuum vanishes. We quantize the field near a nonzero value of the scalar field from the bottom of the valley. After calculation of the one-loop effective action both variants give for the β-function the same exact expression which, in addition, coincides with our previous result extracted from instanton calculus. A few remarks on the problem of anomalies in supersymmetric gauge theories are presented

  11. A new approach to non-Abelian hydrodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Fernández-Melgarejo, Jose J. [Center for the Fundamental Laws of Nature, Harvard University,Cambridge, MA 02138 (United States); Rey, Soo-Jong [School of Physics & Astronomy and Center for Theoretical Physics, Seoul National University,Seoul, 08826 (Korea, Republic of); Department of Fundamental Sciences, University of Science and Technology,Daejeon, 34113 (Korea, Republic of); Center for Gauge, Gravity & Strings, Institute for Basic Sciences,Daejeon, 34047 (Korea, Republic of); Surówka, Piotr [Center for the Fundamental Laws of Nature, Harvard University,Cambridge, MA 02138 (United States); Max-Planck-Institut für Physik (Werner-Heisenberg-Institut),Föhringer Ring 6, D-80805 Munich (Germany)

    2017-02-23

    We present a new approach to describe hydrodynamics carrying non-Abelian macroscopic degrees of freedom. Based on the Kaluza-Klein compactification of a higher-dimensional neutral dissipative fluid on a manifold of non-Abelian isometry, we obtain a four-dimensional colored dissipative fluid coupled to Yang-Mills gauge field. We derive transport coefficients of resulting colored fluid, which feature non-Abelian character of color charges. In particular, we obtain color-specific terms in the gradient expansions and response quantities such as the conductivity matrix and the chemical potentials. We argue that our Kaluza-Klein approach provides a robust description of non-Abelian hydrodynamics, and discuss some links between this system and quark-gluon plasma and fluid/gravity duality.

  12. Actions for non-abelian twisted self-duality

    Science.gov (United States)

    Samtleben, Henning

    2011-10-01

    The dynamics of abelian vector and antisymmetric tensor gauge fields can be described in terms of twisted self-duality equations. These first-order equations relate the p-form fields to their dual forms by demanding that their respective field strengths are dual to each other. It is well known that such equations can be integrated to a local action that carries on equal footing the p-forms together with their duals and is manifestly duality invariant. Space-time covariance is no longer manifest but still present with a non-standard realization of space-time diffeomorphisms on the gauge fields. In this paper, we give a non-abelian generalization of this first-order action by gauging part of its global symmetries. The resulting field equations are non-abelian versions of the twisted self-duality equations. A key element in the construction is the introduction of proper couplings to higher-rank tensor fields. We discuss possible applications (to Yang-Mills and supergravity theories) and comment on the relation to previous no-go theorems.

  13. Charged isotropic non-Abelian dyonic black branes

    Directory of Open Access Journals (Sweden)

    Yves Brihaye

    2015-05-01

    Full Text Available We construct black holes with a Ricci-flat horizon in Einstein–Yang–Mills theory with a negative cosmological constant, which approach asymptotically an AdSd spacetime background (with d≥4. These solutions are isotropic, i.e. all space directions in a hypersurface of constant radial and time coordinates are equivalent, and possess both electric and magnetic fields. We find that the basic properties of the non-Abelian solutions are similar to those of the dyonic isotropic branes in Einstein–Maxwell theory (which, however, exist in even spacetime dimensions only. These black branes possess a nonzero magnetic field strength on the flat boundary metric, which leads to a divergent mass of these solutions, as defined in the usual way. However, a different picture is found for odd spacetime dimensions, where a non-Abelian Chern–Simons term can be incorporated in the action. This allows for black brane solutions with a magnetic field which vanishes asymptotically.

  14. Asymptotic form factor of non-Abelian gauge theories, planar diagrammatics and complex poles as resonances in the analytic s-matrix

    International Nuclear Information System (INIS)

    Knight, D.W.

    1976-01-01

    Reasons are given for studying the form factor and a method for constructing all believed-to-be leading form factor diagrams in a certain class of non-Abelian gauge theories (NAGT's) in typical kinematic limits. The possibility that the form factor ''exponentiates'' in NAGT's (as it does in QED) is discussed. A method is given for constructing all 1CI planar diagrams (this is, all 1PI diagrams except those which separate upon cutting at a vertex) directly from one's heat--that is, without the need to refer to tables, et cetera. It is noted that the material is believed to be essentially completely original, that is, the technique for constructing all 1CI planar diagrams in an iterative fashion is completely new. Of course, one can construct them in an essentially random fashion, but this technique is slow and extremely error prone compared with the iterative technique given. The idea of associating an elastic resonance with a complex pole in the analytic scattering amplitude, T(E), is discussed. Calculations of the pole position and the residue of the Δ 33 resonance are given, along with an analysis of experimentally induced error in the pole position

  15. A Unified Field Theory of Gravity, Electromagnetism, and the Yang-Mills Gauge Field

    Directory of Open Access Journals (Sweden)

    Suhendro I.

    2008-01-01

    Full Text Available In this work, we attempt at constructing a comprehensive four-dimensional unified field theory of gravity, electromagnetism, and the non-Abelian Yang-Mills gauge field in which the gravitational, electromagnetic, and material spin fields are unified as intrinsic geometric objects of the space-time manifold S4 via the connection, with the general- ized non-Abelian Yang-Mills gauge field appearing in particular as a sub-field of the geometrized electromagnetic interaction.

  16. A Unified Field Theory of Gravity, Electromagnetism, and theA Unified Field Theory of Gravity, Electromagnetism, and the Yang-Mills Gauge Field

    Directory of Open Access Journals (Sweden)

    Suhendro I.

    2008-01-01

    Full Text Available In this work, we attempt at constructing a comprehensive four-dimensional unified field theory of gravity, electromagnetism, and the non-Abelian Yang-Mills gauge field in which the gravitational, electromagnetic, and material spin fields are unified as intrinsic geometric objects of the space-time manifold $S_4$ via the connection, with the generalized non-Abelian Yang-Mills gauge field appearing in particular as a sub-field of the geometrized electromagnetic interaction.

  17. Non-Abelian BIonic brane intersections

    International Nuclear Information System (INIS)

    Cook, Paul L.H.; Mello Koch, Robert de; Murugan, Jeff

    2003-01-01

    We study 'fuzzy funnel' solutions to the non-Abelian equations of motion of the D string. Our funnel describes n 6 /360 coincident D-strings ending on n 3 /6 D7-branes, in terms of a fuzzy six-sphere which expands along the string. We also provide a dual description of this configuration in terms of the world volume theory of the D7-branes. Our work makes use of an interesting nonlinear higher dimensional generalization of the instanton equations

  18. Heterotic non-Abelian orbifolds

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, Maximilian [Technische Univ. Muenchen, Garching (Germany). Physik-Department; Ramos-Sanchez, Saul [UNAM, Mexico (Mexico). Dept. of Theoretical Physics; Vaudrevange, Patrick K.S. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2013-04-15

    We perform the first systematic analysis of particle spectra obtained from heterotic string compactifications on non-Abelian toroidal orbifolds. After developing a new technique to compute the particle spectrum in the case of standard embedding based on higher dimensional supersymmetry, we compute the Hodge numbers for all recently classified 331 non-Abelian orbifold geometries which yield N=1 supersymmetry for heterotic compactifications. Surprisingly, most Hodge numbers follow the empiric pattern h{sup (1,1)}-h{sup (2,1)}=0 mod 6, which might be related to the number of three standard model generations. Furthermore, we study the fundamental groups in order to identify the possibilities for non-local gauge symmetry breaking. Three examples are discussed in detail: the simplest non-Abelian orbifold S{sub 3} and two more elaborated examples, T{sub 7} and {Delta}(27), which have only one untwisted Kaehler and no untwisted complex structure modulus. Such models might be especially interesting in the context of no-scale supergravity. Finally, we briefly discuss the case of orbifolds with vanishing Euler numbers in the context of enhanced (spontaneously broken) supersymmetry.

  19. Towards a non-abelian electric-magnetic symmetry: the skeleton group

    NARCIS (Netherlands)

    Kampmeijer, L.; Bais, F.A.; Schroers, B.J.; Slingerland, J.K.

    2010-01-01

    We propose an electric-magnetic symmetry group in non-abelian gauge theory, which we call the skeleton group. We work in the context of non-abelian unbroken gauge symmetry, and provide evidence for our proposal by relating the representation theory of the skeleton group to the labelling and fusion

  20. Studies in quantum field theory

    International Nuclear Information System (INIS)

    Bender, C.M.; Mandula, J.E.; Shrauner, J.E.

    1982-01-01

    Washington University is currently conducting research in many areas of high energy theoretical and mathematical physics. These areas include: strong-coupling approximation; classical solutions of non-Abelian gauge theories; mean-field approximation in quantum field theory; path integral and coherent state representations in quantum field theory; lattice gauge calculations; the nature of perturbation theory in large orders; quark condensation in QCD; chiral symmetry breaking; the l/N expansion in quantum field theory; effective potential and action in quantum field theories, including QCD

  1. Non-abelian charged vortices as cosmic strings

    Energy Technology Data Exchange (ETDEWEB)

    Manias, M.V.; Naon, C.M.; Schaposnik, F.A.; Trobo, M.

    1986-04-24

    We study vortex solutions in non-abelian gauge theories with spontaneous symmetry breaking. We construct string configurations with electric charge showing that they necessarily have infinite energy per unit length. Although this prevents its application in problems like catalysis of proton decay, we show, by analyzing the cosmological evolution of the strings, that they can produce density fluctuations leading to galaxy formation.

  2. On the supersymmetric non-abelian Born-Infeld action

    NARCIS (Netherlands)

    Bergshoeff, E.A.; Roo, M. de; Sevrin, A.

    2001-01-01

    We review an iterative construction of the supersymmetric non-abelian Born-Infeld action. We obtain the action through second order in the field strength. Kappa-invariance fixes the ordenings which turn out to deviate from the symmetrized trace proposal.

  3. An introduction to non-Abelian discrete symmetries for particle physicists

    CERN Document Server

    Ishimori, Hajime; Ohki, Hiroshi; Okada, Hiroshi; Shimizu, Yusuke; Tanimoto, Morimitsu

    2012-01-01

    These lecture notes provide a tutorial review of non-Abelian discrete groups and show some applications to issues in physics where discrete symmetries constitute an important principle for model building in particle physics. While Abelian discrete symmetries are often imposed in order to control couplings for particle physics - in particular model building beyond the standard model - non-Abelian discrete symmetries have been applied to understand the three-generation flavor structure in particular. Indeed, non-Abelian discrete symmetries are considered to be the most attractive choice for the flavor sector: model builders have tried to derive experimental values of quark and lepton masses, and mixing angles by assuming non-Abelian discrete flavor symmetries of quarks and leptons, yet, lepton mixing has already been intensively discussed in this context, as well. The possible origins of the non-Abelian discrete symmetry for flavors is another topic of interest, as they can arise from an underlying theory -...

  4. Group Approach to the Quantization of Non-Abelian Stueckelberg Models

    Energy Technology Data Exchange (ETDEWEB)

    Aldaya, V; Lopez-Ruiz, F F [Instituto de Astrofisica de AndalucIa (IAA-CSIC), Apartado Postal 3004, 18080 Granada (Spain); Calixto, M, E-mail: valdaya@iaa.es, E-mail: Manuel.Calixto@upct.es, E-mail: flopez@iaa.es [Departamento de Matematica Aplicada y Estadistica, Universidad Politecnica de Cartagena, Paseo Alfonso XIII 56, 30203 Cartagena (Spain)

    2011-03-01

    The quantum field theory of Non-Linear Sigma Models on coadjoint orbits of a semi-simple group G are formulated in the framework of a Group Approach to Quantization. In this scheme, partial-trace Lagrangians are recovered from two-cocycles defined on the infinite-dimensional group of sections of the jet-gauge group J{sup 1} (G). This construction is extended to the entire physical system coupled to Yang-Mills fields, thus constituting an algebraic formulation of the Non-Abelian Stueckelgerg formalism devoid of the unitarity/renormalizability obstruction that this theory finds in the standard Lagrangian formalism under canonical quantization.

  5. Algebraic quantum field theory

    International Nuclear Information System (INIS)

    Foroutan, A.

    1996-12-01

    The basic assumption that the complete information relevant for a relativistic, local quantum theory is contained in the net structure of the local observables of this theory results first of all in a concise formulation of the algebraic structure of the superselection theory and an intrinsic formulation of charge composition, charge conjugation and the statistics of an algebraic quantum field theory. In a next step, the locality of massive particles together with their spectral properties are wed for the formulation of a selection criterion which opens the access to the massive, non-abelian quantum gauge theories. The role of the electric charge as a superselection rule results in the introduction of charge classes which in term lead to a set of quantum states with optimum localization properties. Finally, the asymptotic observables of quantum electrodynamics are investigated within the framework of algebraic quantum field theory. (author)

  6. Lectures on quantum field theory

    CERN Document Server

    Das, Ashok

    2008-01-01

    This book consists of the lectures for a two-semester course on quantum field theory, and as such is presented in a quite informal and personal manner. The course starts with relativistic one-particle systems, and develops the basics of quantum field theory with an analysis of the representations of the Poincaré group. Canonical quantization is carried out for scalar, fermion, Abelian and non-Abelian gauge theories. Covariant quantization of gauge theories is also carried out with a detailed description of the BRST symmetry. The Higgs phenomenon and the standard model of electroweak interactio

  7. Gauging the nonlinear sigma-model through a non-Abelian algebra

    Energy Technology Data Exchange (ETDEWEB)

    Barcelos Neto, J. [Universidade Federal, Rio de Janeiro, RJ (Brazil); Oliveira, W. [Juiz de Fora Univ., MG (Brazil)

    1997-12-31

    We have used an extension of the BFFT formalism presented by Banerjee et al. in order to gauge the nonlinear sigma model by means of a non-Abelian algebra. we have considered the supersymmetric and the usual cases. We have shown that the supersymmetric case is only consistently transformed in a first-class theory by means of a non-Abelian algebra. The usual BFFT treatment leads to a nonlocal theory. (author) 6 refs.

  8. Non-abelian bosonization and higher spin symmetries

    International Nuclear Information System (INIS)

    Zaikov, R.P.

    1995-03-01

    The higher spin properties of the non-abelian bosonization in the classical theory are investigated. Both the symmetry transformation algebra and the classical current algebra for the non-abelian free fermionic model are linear Gel'fand-Dickey type algebras. However, for the corresponding WZNW model these algebras are different. There exist symmetry transformations which algebra remains the linear Gel'fand-Dickey algebra while in the corresponding current algebra nonlinear terms arised. Moreover, this algebra is closed (in Casimir form) only in an extended current space in which nonlinear currents are included. In the affine sector, it is necessary to include higher isotopic spin current too. As result we have have a triple extended algebra. (author). 30 refs

  9. Marginal and non-commutative deformations via non-abelian T-duality

    Energy Technology Data Exchange (ETDEWEB)

    Hoare, Ben [Institut für Theoretische Physik, ETH Zürich,Wolfgang-Pauli-Strasse 27, 8093 Zürich (Switzerland); Thompson, Daniel C. [Theoretische Natuurkunde, Vrije Universiteit Brussel & The International Solvay Institutes, Pleinlaan 2, B-1050 Brussels (Belgium)

    2017-02-10

    In this short article we develop recent proposals to relate Yang-Baxter sigma-models and non-abelian T-duality. We demonstrate explicitly that the holographic space-times associated to both (multi-parameter)-β-deformations and non-commutative deformations of N=4 super Yang-Mills gauge theory including the RR fluxes can be obtained via the machinery of non-abelian T-duality in Type II supergravity.

  10. Non-Abelian Braiding of Light

    Science.gov (United States)

    Iadecola, Thomas; Schuster, Thomas; Chamon, Claudio

    2016-08-01

    Many topological phenomena first proposed and observed in the context of electrons in solids have recently found counterparts in photonic and acoustic systems. In this work, we demonstrate that non-Abelian Berry phases can arise when coherent states of light are injected into "topological guided modes" in specially fabricated photonic waveguide arrays. These modes are photonic analogues of topological zero modes in electronic systems. Light traveling inside spatially well-separated topological guided modes can be braided, leading to the accumulation of non-Abelian phases, which depend on the order in which the guided beams are wound around one another. Notably, these effects survive the limit of large photon occupation, and can thus also be understood as wave phenomena arising directly from Maxwell's equations, without resorting to the quantization of light. We propose an optical interference experiment as a direct probe of this non-Abelian braiding of light.

  11. Particles, fields and quantum theory

    International Nuclear Information System (INIS)

    Bongaarts, P.J.M.

    1982-01-01

    The author gives an introduction to the development of gauge theories of the fundamental interactions. Starting from classical mechanics and quantum mechanics the development of quantum electrodynamics and non-abelian gauge theories is described. (HSI)

  12. A non-perturbative argument for the non-abelian Higgs mechanism

    International Nuclear Information System (INIS)

    De Palma, G.; Strocchi, F.

    2013-01-01

    The evasion of massless Goldstone bosons by the non-abelian Higgs mechanism is proved by a non-perturbative argument in the local BRST gauge. -- Highlights: •The perturbative explanation of the Higgs mechanism (HM) is not under mathematical control. •We offer a non-perturbative proof of the absence of Goldstone bosons from the non-abelian HM. •Our non-perturbative proof in the BRST gauge avoids a mean field ansatz and expansion

  13. A non-perturbative argument for the non-abelian Higgs mechanism

    Energy Technology Data Exchange (ETDEWEB)

    De Palma, G. [Scuola Normale Superiore, Pisa (Italy); INFN, Sezione di Pisa, Pisa (Italy); Strocchi, F., E-mail: franco.strocchi@sns.it [INFN, Sezione di Pisa, Pisa (Italy)

    2013-09-15

    The evasion of massless Goldstone bosons by the non-abelian Higgs mechanism is proved by a non-perturbative argument in the local BRST gauge. -- Highlights: •The perturbative explanation of the Higgs mechanism (HM) is not under mathematical control. •We offer a non-perturbative proof of the absence of Goldstone bosons from the non-abelian HM. •Our non-perturbative proof in the BRST gauge avoids a mean field ansatz and expansion.

  14. Nonperturbative quantization ‘a la Heisenberg for non-Abelian gauge theories: two-equation approximation. Applications: a flux tube solution and a scalar model of glueball

    Directory of Open Access Journals (Sweden)

    Dzhunushaliev Vladimir

    2017-01-01

    Full Text Available The nonperturbative quantization technique à la Heisenberg is applied for the SU(3 gauge theory. The operator Yang-Mills equation and corresponding infinite set of equations for all Green’s functions are considered. Gauge degrees of freedom are splitted into two groups: (1 Aμa ∈ SU (2 × U(1 ⊂ SU(3; (2 coset degrees of freedom SU(3/SU(2 × U(1. Using some assumptions about 2- and 4-point Green’s functions, the infinite set of equations is truncated to two equations. The first equation is the SU(2 × U(1 Yang-Mills equation, and the second equation describes a gluon condensate formed by coset fields. A flux tube solution describing longitudinal color electric fields stretched between quark and antiquark located at the ± infinities is obtained. It is shown that the dual Meissner effect appears in this solution: the electric field is pushed out from the gluon condensate.

  15. Large $N$ QCD and $q$-Deformed Quantum Field Theories

    OpenAIRE

    Aref'eva, I. Ya.

    1996-01-01

    A construction of master field describing multicolour QCD is presented. The master fields for large N matrix theories satisfy to standard equations of relativistic field theory but fields are quantized according $q$-deformed commutation relations with $q=0$. These commutation relations are realized in the Boltzmannian Fock space. The master field for gauge theory does not take values in a finite-dimensional Lie algebra, however, there is a non-Abelian gauge symmetry and BRST-invariance.

  16. Exotic Non-Abelian Topological Defects in Lattice Fractional Quantum Hall States

    Science.gov (United States)

    Liu, Zhao; Möller, Gunnar; Bergholtz, Emil J.

    2017-09-01

    We investigate extrinsic wormholelike twist defects that effectively increase the genus of space in lattice versions of multicomponent fractional quantum Hall systems. Although the original band structure is distorted by these defects, leading to localized midgap states, we find that a new lowest flat band representing a higher genus system can be engineered by tuning local single-particle potentials. Remarkably, once local many-body interactions in this new band are switched on, we identify various Abelian and non-Abelian fractional quantum Hall states, whose ground-state degeneracy increases with the number of defects, i.e, with the genus of space. This sensitivity of topological degeneracy to defects provides a "proof of concept" demonstration that genons, predicted by topological field theory as exotic non-Abelian defects tied to a varying topology of space, do exist in realistic microscopic models. Specifically, our results indicate that genons could be created in the laboratory by combining the physics of artificial gauge fields in cold atom systems with already existing holographic beam shaping methods for creating twist defects.

  17. Non-abelian bosonization in two and three dimensions

    International Nuclear Information System (INIS)

    Le Guillou, J.C.; Moreno, E.; Nunez, C.; Schaposnik, F.A.

    1997-01-01

    We discuss non-abelian bosonization of two- and three-dimensional fermions using a path-integral framework in which the bosonic action follows from the evaluation of the fermion determinant for the Dirac operator in the presence of a vector field. This naturally leads to the Wess-Zumino-Witten action for massless two-dimensional fermions and to a Chern-Simons action for very massive three-dimensional fermions. One advantage of our approach is that it allows one to derive the exact bosonization recipe for fermion currents in a systematic way. (orig.)

  18. Non-abelian Z-theory: Berends-Giele recursion for the α{sup ′}-expansion of disk integrals

    Energy Technology Data Exchange (ETDEWEB)

    Mafra, Carlos R. [STAG Research Centre and Mathematical Sciences, University of Southampton,Southampton (United Kingdom); Institute for Advanced Study, School of Natural Sciences,Einstein Drive, Princeton, NJ 08540 (United States); Schlotterer, Oliver [Max-Planck-Institut für Gravitationsphysik, Albert-Einstein-Institut,Am Mühlenberg 1, 14476 Potsdam (Germany)

    2017-01-09

    We present a recursive method to calculate the α{sup ′}-expansion of disk integrals arising in tree-level scattering of open strings which resembles the approach of Berends and Giele to gluon amplitudes. Following an earlier interpretation of disk integrals as doubly partial amplitudes of an effective theory of scalars dubbed as Z-theory, we pinpoint the equation of motion of Z-theory from the Berends-Giele recursion for its tree amplitudes. A computer implementation of this method including explicit results for the recursion up to order α{sup ′7} is made available on the website repo.or.cz/BGap.git.

  19. Gauging the nonlinear {sigma} model through a non-Abelian algebra

    Energy Technology Data Exchange (ETDEWEB)

    Barcelos-Neto, J.; Oliveira, W. [Instituto de Fisica, Universidade Federal do Rio de Janeiro, RJ 21945-970, Caixa Postal 68528 (Brazil)

    1997-08-01

    We use an extension of the method due to Batalin, Fradkin, Fradkina, and Tyutin (BFFT) for transforming the nonlinear {sigma} model in a non-Abelian gauge theory. We deal with both supersymmetric and nonsupersymmetric cases. The bosonic case was already considered in the literature but just gauged with an Abelian algebra. We show that the supersymmetric version is only compatible with a non-Abelian gauge theory. The usual BFFT method for this case leads to a nonlocal algebra. {copyright} {ital 1997} {ital The American Physical Society}

  20. Quantisation of monopoles with non-abelian magnetic charge

    Energy Technology Data Exchange (ETDEWEB)

    Bais, F.A.; Schroers, B.J. [Amsterdam Univ. (Netherlands). Inst. voor Theoretische Fysica

    1998-02-16

    Magnetic monopoles in Yang-Mills-Higgs theory with a non-abelian unbroken gauge group are classified by holomorphic charges in addition to the topological charges familiar from the abelian case. As a result the moduli spaces of monopoles of given topological charge are stratified according to the holomorphic charges. Here the physical consequences of the stratification are explored in the case where the gauge group SU(3) is broken to U(2). The description due to Dancer of the moduli space of charge-two monopoles is reviewed and interpreted physically in terms of non-abelian magnetic dipole moments. Semi-classical quantisation leads to dyonic states which are labelled by a magnetic charge and a representation of the subgroup of U(2) which leaves the magnetic charge invariant (centraliser subgroup). A key result of this paper is that these states fall into representations of the semi-direct product U(2) x R{sup 4}. The combination rules (Clebsch-Gordan coefficients) of dyonic states can thus be deduced. Electric-magnetic duality properties of the theory are discussed in the light of our results, and supersymmetric dyonic BPS states which fill the SL(2,Z) orbit of the basic massive W-bosons are found. (orig.). 48 refs.

  1. Matrix product states and the non-Abelian rotor model

    Science.gov (United States)

    Milsted, Ashley

    2016-04-01

    We use uniform matrix product states to study the (1 +1 )D O (2 ) and O (4 ) rotor models, which are equivalent to the Kogut-Susskind formulation of matter-free non-Abelian lattice gauge theory on a "Hawaiian earring" graph for U (1 ) and S U (2 ), respectively. Applying tangent space methods to obtain ground states and determine the mass gap and the β function, we find excellent agreement with known results, locating the Berezinskii-Kosterlitz-Thouless transition for O (2 ) and successfully entering the asymptotic weak-coupling regime for O (4 ). To obtain a finite local Hilbert space, we truncate in the space of generalized Fourier modes of the gauge group, comparing the effects of different cutoff values. We find that higher modes become important in the crossover and weak-coupling regimes of the non-Abelian theory, where entanglement also suddenly increases. This could have important consequences for tensor network state studies of Yang-Mills on higher-dimensional graphs.

  2. Self-dual non-Abelian N=1 tensor multiplet in D=2+2 dimensions

    Science.gov (United States)

    Nishino, Hitoshi; Rajpoot, Subhash

    2012-10-01

    We present a self-dual non-Abelian N=1 supersymmetric tensor multiplet in D=2+2 space-time dimensions. Our system has three on-shell multiplets: (i) The usual non-Abelian Yang-Mills multiplet (AμI,λI), (ii) a non-Abelian tensor multiplet (BμνI,χI,φI), and (iii) an extra compensator vector multiplet (CμI,ρI). Here the index I is for the adjoint representation of a non-Abelian gauge group. The duality symmetry relations are GμνρI=-ɛμνρσ∇σφI, FμνI=+(1/2)ɛμνρσFρσI, and HμνI=+(1/2)ɛμνρσHρσI, where G and H are respectively the field strengths of B and C. The usual problem with the coupling of the non-Abelian tensor is avoided by non-trivial Chern-Simons terms in the field strengths GμνρI and HμνI. For an independent confirmation, we re-formulate the component results in superspace. As applications of embedding integrable systems, we show how the N=2, r=3 and N=3, r=4 flows of generalized Korteweg-de Vries equations are embedded into our system.

  3. Critical string from non-Abelian vortex in four dimensions

    Directory of Open Access Journals (Sweden)

    M. Shifman

    2015-11-01

    Full Text Available In a class of non-Abelian solitonic vortex strings supported in certain N=2 super-Yang–Mills theories we search for the vortex which can behave as a critical fundamental string. We use the Polchinski–Strominger criterion of the ultraviolet completeness. We identify an appropriate four-dimensional bulk theory: it has the U(2 gauge group, the Fayet–Iliopoulos term and four flavor hypermultiplets. It supports semilocal vortices with the world-sheet theory for orientational (size moduli described by the weighted CP(2,2 model. The latter is superconformal. Its target space is six-dimensional. The overall Virasoro central charge is critical. We show that the world-sheet theory on the vortex supported in this bulk model is the bona fide critical string.

  4. On Non-Abelian Symplectic Cutting

    DEFF Research Database (Denmark)

    Martens, Johan; Thaddeus, Michael

    2012-01-01

    We discuss symplectic cutting for Hamiltonian actions of non-Abelian compact groups. By using a degeneration based on the Vinberg monoid we give, in good cases, a global quotient description of a surgery construction introduced by Woodward and Meinrenken, and show it can be interpreted in algebro......-geometric terms. A key ingredient is the `universal cut' of the cotangent bundle of the group itself, which is identified with a moduli space of framed bundles on chains of projective lines recently introduced by the authors....

  5. Reissner–Nordström black holes with non-Abelian hair

    Directory of Open Access Journals (Sweden)

    Carlos Herdeiro

    2017-09-01

    Full Text Available We consider d⩾4 Einstein–(extended-Yang–Mills theory, where the gauge sector is augmented by higher order terms. Linearising the (extended Yang–Mills equations on the background of the electric Reissner–Nordström (RN black hole, we show the existence of normalisable zero modes, dubbed non-Abelian magnetic stationary clouds. The non-linear realisation of these clouds bifurcates the RN family into a branch of static, spherically symmetric, electrically charged and asymptotically flat black holes with non-Abelian hair. Generically, the hairy black holes are thermodynamically preferred over the RN solution, which, in this model, becomes unstable against the formation of non-Abelian hair, for sufficiently large values of the electric charge.

  6. Reissner-Nordström black holes with non-Abelian hair

    Science.gov (United States)

    Herdeiro, Carlos; Paturyan, Vanush; Radu, Eugen; Tchrakian, D. H.

    2017-09-01

    We consider d ⩾ 4 Einstein-(extended-)Yang-Mills theory, where the gauge sector is augmented by higher order terms. Linearising the (extended) Yang-Mills equations on the background of the electric Reissner-Nordström (RN) black hole, we show the existence of normalisable zero modes, dubbed non-Abelian magnetic stationary clouds. The non-linear realisation of these clouds bifurcates the RN family into a branch of static, spherically symmetric, electrically charged and asymptotically flat black holes with non-Abelian hair. Generically, the hairy black holes are thermodynamically preferred over the RN solution, which, in this model, becomes unstable against the formation of non-Abelian hair, for sufficiently large values of the electric charge.

  7. Study of the 'non-Abelian' current algebra of a non-linear σ-model

    International Nuclear Information System (INIS)

    Ghosh, Subir

    2006-01-01

    A particular form of non-linear σ-model, having a global gauge invariance, is studied. The detailed discussion on current algebra structures reveals the non-Abelian nature of the invariance, with field dependent structure functions. Reduction of the field theory to a point particle framework yields a non-linear harmonic oscillator, which is a special case of similar models studied before in [J.F. Carinena et al., Nonlinearity 17 (2004) 1941, math-ph/0406002; J.F. Carinena et al., in: Proceedings of 10th International Conference in Modern Group Analysis, Larnaca, Cyprus, 2004, p. 39, math-ph/0505028; J.F. Carinena et al., Rep. Math. Phys. 54 (2004) 285, hep-th/0501106]. The connection with non-commutative geometry is also established

  8. Non-perturbative decay of non-Abelian hair

    Science.gov (United States)

    Cano, Pablo A.; Ortín, Tomás

    2017-12-01

    We construct a solution of Heterotic supergravity which interpolates between two different AdS3 × S3 × T4 geometries corresponding to the near-horizon limits of two 5-dimensional black holes, only one of which has non-Abelian hair. This solution can be used to estimate the amplitude of probability of the non-perturbative decay of the gauge 5-brane responsible for the non-Abelian hair into eight solitonic 5-branes by evaluating its Euclidean action. The Wick rotation of this solution poses several problems which we argue can be overcome by using a non-extremal off-shell (NEOS) deformation of the solution. This NEOS field configuration can be Wick rotated straight away and its Euclidean action can be computed for any value of the deformation parameter. The Euclidean result can then be anti-Wick-rotated and its extremal limit gives the Euclidean action of the original solution, which turns out to be one half of the difference between the entropies of the 5-dimensional black holes.

  9. Metal-Insulator Transition Revisited for Cold Atoms in Non-Abelian Gauge Potentials

    International Nuclear Information System (INIS)

    Satija, Indubala I.; Dakin, Daniel C.; Clark, Charles W.

    2006-01-01

    We discuss the possibility of realizing metal-insulator transitions with ultracold atoms in two-dimensional optical lattices in the presence of artificial gauge potentials. For Abelian gauges, such transitions occur when the magnetic flux penetrating the lattice plaquette is an irrational multiple of the magnetic flux quantum. Here we present the first study of these transitions for non-Abelian U(2) gauge fields. In contrast to the Abelian case, the spectrum and localization transition in the non-Abelian case is strongly influenced by atomic momenta. In addition to determining the localization boundary, the momentum fragments the spectrum. Other key characteristics of the non-Abelian case include the absence of localization for certain states and satellite fringes around the Bragg peaks in the momentum distribution and an interesting possibility that the transition can be tuned by the atomic momenta

  10. Projected Entangled Pair States with non-Abelian gauge symmetries: An SU(2) study

    Energy Technology Data Exchange (ETDEWEB)

    Zohar, Erez, E-mail: erez.zohar@mpq.mpg.de [Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Straße 1, 85748 Garching (Germany); Wahl, Thorsten B. [Rudolf Peierls Centre for Theoretical Physics, Oxford, 1 Keble Road, OX1 3NP (United Kingdom); Burrello, Michele, E-mail: michele.burrello@mpq.mpg.de [Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Straße 1, 85748 Garching (Germany); Cirac, J. Ignacio [Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Straße 1, 85748 Garching (Germany)

    2016-11-15

    Over the last years, Projected Entangled Pair States have demonstrated great power for the study of many body systems, as they naturally describe ground states of gapped many body Hamiltonians, and suggest a constructive way to encode and classify their symmetries. The PEPS study is not only limited to global symmetries, but has also been extended and applied for local symmetries, allowing to use them for the description of states in lattice gauge theories. In this paper we discuss PEPS with a local, SU(2) gauge symmetry, and demonstrate the use of PEPS features and techniques for the study of a simple family of many body states with a non-Abelian gauge symmetry. We present, in particular, the construction of fermionic PEPS able to describe both two-color fermionic matter and the degrees of freedom of an SU(2) gauge field with a suitable truncation.

  11. Non-Abelian, supersymmetric black holes and strings in 5 dimensions

    International Nuclear Information System (INIS)

    Meessen, Patrick; Ortín, Tomás; Ramírez, Pedro F.

    2016-01-01

    We construct and study the first supersymmetric black-hole and black-string solutions of non-Abelian-gauged N=1,d=5 supergravity (N=1,d=5 Super-Einstein-Yang-Mills theory) with non-trivial SU(2) gauge fields: BPST instantons for black holes and BPS monopoles of different kinds (’t Hooft-Polyakov, Wu-Yang and Protogenov) for black strings and also for certain black holes that are well defined solutions only for very specific values of all the moduli. Instantons, as well as colored monopoles do not contribute to the masses and tensions but do contribute to the entropies. The construction is based on the characterization of the supersymmetric solutions of gauged N=1,d=5 supergravity coupled to vector multiplets achieved in ref. http://dx.doi.org/10.1088/1126-6708/2007/08/096 which we elaborate upon by finding the rules to construct supersymmetric solutions with one additional isometry, both for the timelike and null classes. These rules automatically connect the timelike and null non-Abelian supersymmetric solutions of N=1,d=5 SEYM theory with the timelike ones of N=2,d=4 SEYM theory http://dx.doi.org/10.1103/PhysRevD.78.065031; http://dx.doi.org/10.1088/1126-6708/2008/09/099 by dimensional reduction and oxidation. In the timelike-to-timelike case the singular Kronheimer reduction recently studied in ref. http://dx.doi.org/10.1016/j.physletb.2015.04.065 plays a crucial role.

  12. Topological superfluids on a square optical lattice with non-Abelian gauge fields: Effects of next-nearest-neighbor hopping in the BCS-BEC evolution

    Science.gov (United States)

    Iskin, M.

    2016-01-01

    We consider a two-component Fermi gas with attractive interactions on a square optical lattice, and study the interplay of Zeeman field, spin-orbit coupling, and next-nearest-neighbor hopping on the ground-state phase diagrams in the entire BCS-BEC evolution. In particular, we first classify and distinguish all possible superfluid phases by the momentum-space topology of their zero-energy quasiparticle-quasihole excitations, and then numerically establish a plethora of quantum phase transitions in between. These transitions are further signaled and evidenced by the changes in the corresponding topological invariant of the system, i.e., its Chern number. Lastly, we find that the superfluid phase exhibits a reentrant structure, separated by a fingering normal phase, the origin of which is traced back to the changes in the single-particle density of states.

  13. Condensation of an ideal gas obeying non-Abelian statistics.

    Science.gov (United States)

    Mirza, Behrouz; Mohammadzadeh, Hosein

    2011-09-01

    We consider the thermodynamic geometry of an ideal non-Abelian gas. We show that, for a certain value of the fractional parameter and at the relevant maximum value of fugacity, the thermodynamic curvature has a singular point. This indicates a condensation such as Bose-Einstein condensation for non-Abelian statistics and we work out the phase transition temperature in various dimensions.

  14. Quillen bundle and geometric prequantization of non-abelian ...

    Indian Academy of Sciences (India)

    Toepliz operators out of projections to holomorphic sections of the prequatum line bundle. (when the latter makes sense) and Berezin–Toeplitz deformation quantization has been carried out by Andersen in [1, 2]. The non-abelian vortices were first introduced in the literature perhaps by Bradlow [8]. The non-abelian vortex ...

  15. New scheme for color confinement and violation of the non-Abelian Bianchi identities

    Science.gov (United States)

    Suzuki, Tsuneo; Ishiguro, Katsuya; Bornyakov, Vitaly

    2018-02-01

    A new scheme for color confinement in QCD due to violation of the non-Abelian Bianchi identities is proposed. The violation of the non-Abelian Bianchi identities (VNABI) Jμ is equal to Abelian-like monopole currents kμ defined by the violation of the Abelian-like Bianchi identities. Although VNABI is an adjoint operator satisfying the covariant conservation law DμJμ=0 , it satisfies, at the same time, the Abelian-like conservation law ∂μJμ=0 . The Abelian-like conservation law ∂μJμ=0 is also gauge-covariant. There are N2-1 conserved magnetic charges in the case of color S U (N ). The charge of each component of VNABI is quantized à la Dirac. The color-invariant eigenvalues λμ of VNABI also satisfy the Abelian conservation law ∂μλμ=0 and the magnetic charges of the eigenvalues are also quantized à la Dirac. If the color invariant eigenvalues condense in the QCD vacuum, each color component of the non-Abelian electric field Ea is squeezed by the corresponding color component of the solenoidal current Jμa. Then only the color singlets alone can survive as a physical state and non-Abelian color confinement is realized. This confinement picture is completely new in comparison with the previously studied monopole confinement scenario based on an Abelian projection after some partial gauge-fixing, where Abelian neutral states can survive as physical. To check if the scenario is realized in nature, numerical studies are done in the framework of lattice field theory by adopting pure S U (2 ) gauge theory for simplicity. Considering Jμ(x )=kμ(x ) in the continuum formulation, we adopt an Abelian-like definition of a monopole following DeGrand-Toussaint as a lattice version of VNABI, since the Dirac quantization condition of the magnetic charge is satisfied on lattice partially. To reduce severe lattice artifacts, we introduce various techniques of smoothing the thermalized vacuum. Smooth gauge fixings such as the maximal center gauge (MCG), block

  16. Multiflavor QCD* on R_3 * S_1: Studying Transition From Abelian to Non-Abelian Confinement

    Energy Technology Data Exchange (ETDEWEB)

    Shifman, M.; /Minnesota U., Theor. Phys. Inst.; Unsal, M.; /SLAC /Stanford U., Phys. Dept.

    2009-03-31

    The center-stabilized multiflavor QCD* theories formulated on R{sub 3} x S{sub 1} exhibit both Abelian and non-Abelian confinement as a function of the S{sub 1} radius, similar to the Seiberg-Witten theory as a function of the mass deformation parameter. For sufficiently small number of flavors and small r(S{sub 1}), we show occurrence of a mass gap in gauge fluctuations, and linear confinement. This is a regime of confinement without continuous chiral symmetry breaking ({chi}SB). Unlike one-flavor theories where there is no phase transition in r(S{sub 1}), the multiflavor theories possess a single phase transition associated with breaking of the continuous {chi}S. We conjecture that the scale of the {chi}SB is parametrically tied up with the scale of Abelian to non-Abelian confinement transition.

  17. Affine field theories

    International Nuclear Information System (INIS)

    Cadavid, A.C.

    1989-01-01

    The author constructs a non-Abelian field theory by gauging a Kac-Moody algebra, obtaining an infinite tower of interacting vector fields and associated ghosts, that obey slightly modified Feynman rules. She discusses the spontaneous symmetry breaking of such theory via the Higgs mechanism. If the Higgs particle lies in the Cartan subalgebra of the Kac-Moody algebra, the previously massless vectors acquire a mass spectrum that is linear in the Kac-Moody index and has additional fine structure depending on the associated Lie algebra. She proceeds to show that there is no obstacle in implementing the affine extension of supersymmetric Yang-Mills theories. The result is valid in four, six and ten space-time dimensions. Then the affine extension of supergravity is investigated. She discusses only the loop algebra since the affine extension of the super-Poincare algebra appears inconsistent. The construction of the affine supergravity theory is carried out by the group manifold method and leads to an action describing infinite towers of spin 2 and spin 3/2 fields that interact subject to the symmetries of the loop algebra. The equations of motion satisfy the usual consistency check. Finally, she postulates a theory in which both the vector and scalar fields lie in the loop algebra of SO(3). This theory has an expanded soliton sector, and corresponding to the original 't Hooft-Polyakov solitonic solutions she now finds an infinite family of exact, special solutions of the new equations. She also proposes a perturbation method for obtaining an arbitrary solution of those equations for each level of the affine index

  18. Verifying non-Abelian statistics by numerical braiding Majorana fermions

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Qiu-Bo [Department of Physics, Beijing Normal University, Beijing, 100875 (China); He, Jing [Department of Physics, Hebei Normal University, Hebei, 050024 (China); Kou, Su-Peng, E-mail: spkou@bnu.edu.cn [Department of Physics, Beijing Normal University, Beijing, 100875 (China)

    2016-02-15

    Recently, Majorana fermions have attracted intensive attention because of their possible non-Abelian statistics and potential applications in topological quantum computation. This paper describes an approach to verify the non-Abelian statistics of Majorana fermions in topological superconductors. From the relationship between the braiding operator of Majorana fermions and that of Bogoliubov–de Gennes states, we determine that Majorana fermions in one-dimensional and two-dimensional topological superconductors both obey non-Abelian statistics. - Highlights: • The braiding of Majorana fermions is an adiabatic evolution. • The approach to calculate Berry phase in the braiding is proposed. • Verifying non-Abelian statistics of Majorara Fermions induced in different systems.

  19. Gauge-invariant fields and flow equations for Yang-Mills theories

    OpenAIRE

    Wetterich, C.

    2017-01-01

    We discuss the concept of gauge-invariant fields for non-abelian gauge theories. Infinitesimal fluctuations around a given gauge field can be split into physical and gauge fluctuations. Starting from some reference field the gauge-invariant fields are constructed by consecutively adding physical fluctuations. An effective action that depends on gauge-invariant fields becomes a gauge-invariant functional of arbitrary gauge fields by associating to every gauge field the corresponding gauge-inva...

  20. Bosonization methods in string theory

    International Nuclear Information System (INIS)

    Abdalla, E.

    1988-02-01

    The use of bosonization/fermionization techniques to convert non-linear operators of the dual, is discussed. Non abelian bosonization to the case where the central charge of the Kac-Moody algebra is not unity, is generalized. In particular, using this generalization of non-abelian bosonization, the bosonic string vertex of the compactified theory; turns out to be fundamental field of thre fermionic theory, or bound states of it thus permiting explicit computations easily. (author) [pt

  1. Scattering of charged tensor bosons in gauge and superstring theories

    CERN Document Server

    Antoniadis, Ignatios

    2010-01-01

    We calculate the leading-order scattering amplitude of one vector and two tensor gauge bosons in a recently proposed non-Abelian tensor gauge field theory and open superstring theory. The linear in momenta part of the superstring amplitude has identical Lorentz structure with the gauge theory, while its cubic in momenta part can be identified with an effective Lagrangian which is constructed using generalized non-Abelian field strength tensors.

  2. [Studies in quantum field theory

    International Nuclear Information System (INIS)

    1990-01-01

    During the period 4/1/89--3/31/90 the theoretical physics group supported by Department of Energy Contract No. AC02-78ER04915.A015 and consisting of Professors Bender and Shrauner, Associate Professor Papanicolaou, Assistant Professor Ogilvie, and Senior Research Associate Visser has made progress in many areas of theoretical and mathematical physics. Professors Bender and Shrauner, Associate Professor Papanicolaou, Assistant Professor Ogilvie, and Research Associate Visser are currently conducting research in many areas of high energy theoretical and mathematical physics. These areas include: strong-coupling approximation; classical solutions of non-Abelian gauge theories; mean-field approximation in quantum field theory; path integral and coherent state representations in quantum field theory; lattice gauge calculations; the nature of perturbation theory in large order; quark condensation in QCD; chiral symmetry breaking; the 1/N expansion in quantum field theory; effective potential and action in quantum field theories, including OCD; studies of the early universe and inflation, and quantum gravity

  3. Dual projection of chiral p-forms in D = 2: The non-Abelian, PST and supersymmetric formulations of Hull's notons

    International Nuclear Information System (INIS)

    Abreu, E.M.C.

    2002-08-01

    Chiral p-forms are, in fact, present in many supersymmetric and supergravity models in two, six and ten dimensions. In this work, the dual projection procedure, which is essentially equivalent to a canonical transformation, is used to diagonalize some theories in D = 2 (0-forms). The dual projection performed here provides an alternative way of gauging the chiral components without the necessity of constraints. It is shown, through the dual projection, that the nonmover field (the noton) initially introduced by Hull to cancel out the Siegel anomaly, has non-Abelian, PST and supersymmetric formulations. (author)

  4. Residual non-Abelian dark matter and dark radiation

    Directory of Open Access Journals (Sweden)

    P. Ko

    2017-05-01

    Full Text Available We propose a novel particle physics model in which vector dark matter (VDM and dark radiation (DR originate from the same non-Abelian dark sector. We show an illustrating example where dark SU(3 is spontaneously broken into SU(2 subgroup by the nonzero vacuum expectation value (VEV of a complex scalar in fundamental representation of SU(3. The massless gauge bosons associated with the residual unbroken SU(2 constitute DR and help to relieve the tension in Hubble constant measurements between Planck and Hubble Space Telescope. In the meantime, massive dark gauge bosons associated with the broken generators are VDM candidates. Intrinsically, this non-Abelian VDM can interact with non-Abelian DR in the cosmic background, which results in a suppressed matter power spectrum and leads to a smaller σ8 for structure formation.

  5. Four loop wave function renormalization in the non-abelian Thirring model

    International Nuclear Information System (INIS)

    Ali, D.B.; Gracey, J.A.

    2001-01-01

    We compute the anomalous dimension of the fermion field with N f flavours in the fundamental representation of a general Lie colour group in the non-abelian Thirring model at four loops. The implications on the renormalization of the two point Green's function through the loss of multiplicative renormalizability of the model in dimensional regularization due to the appearance of evanescent four fermi operators are considered at length. We observe the appearance of one new colour group Casimir, d F abcd d F abcd , in the final four loop result and discuss its consequences for the relation of the Knizhnik-Zamolodchikov critical exponents in the Wess-Zumino-Witten-Novikov model to the non-abelian Thirring model. Renormalization scheme changes are also considered to ensure that the underlying Fierz symmetry broken by dimensional regularization is restored

  6. Abelian and non-abelian geometric phase in quantum interferometry

    International Nuclear Information System (INIS)

    Bartlett, S.D.; Sanders, B.C.; De Guise, H.

    2000-01-01

    Full text: We present the first scheme for producing and measuring an Abelian geometric phase shift in a three level system where states are invariant under a non Abelian group. In contrast to existing experiments and proposals for experiments, based on U(1 )-invariant states, our scheme geodesically evolves U(2)-invariant states in a four-dimensional SU(3)/U(2) space and is physically realised via a three-channel optical interferometer. We also propose an optical experiment to measure a non-Abelian geometric phase in a system that includes polarisation

  7. Effective field theory for magnetic compactifications

    Science.gov (United States)

    Buchmuller, Wilfried; Dierigl, Markus; Dudas, Emilian; Schweizer, Julian

    2017-04-01

    Magnetic flux plays an important role in compactifications of field and string theories in two ways, it generates a multiplicity of chiral fermion zero modes and it can break supersymmetry. We derive the complete four-dimensional effective action for N = 1 supersymmetric Abelian and non-Abelian gauge theories in six dimensions compactified on a torus with flux. The effective action contains the tower of charged states and it accounts for the mass spectrum of bosonic and fermionic fields as well as their level-dependent interactions. This allows us to compute quantum corrections to the mass and couplings of Wilson lines. We find that the one-loop corrections vanish, contrary to the case without flux. This can be traced back to the spontaneous breaking of symmetries of the six-dimensional theory by the background gauge field, with the Wilson lines as Goldstone bosons.

  8. Effective field theory for magnetic compactifications

    Energy Technology Data Exchange (ETDEWEB)

    Buchmuller, Wilfried; Dierigl, Markus; Schweizer Julian [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Dudas, Emilian [Univ. Paris-Saclay, Palaiseau (France). Ecole Polytechnique

    2016-12-15

    Magnetic flux plays an important role in compactifications of field and string theories in two ways, it generates a multiplicity of chiral fermion zero modes and it can break supersymmetry. We derive the complete four-dimensional effective action for N=1 supersymmetric Abelian and non-Abelian gauge theories in six dimensions compactified on a torus with flux. The effective action contains the tower of charged states and it accounts for the mass spectrum of bosonic and fermionic fields as well as their level-dependent interactions. This allows us to compute quantum corrections to the mass and couplings of Wilson lines. We find that the one-loop corrections vanish, contrary to the case without flux. This can be traced back to the spontaneous breaking of symmetries of the six-dimensional theory by the background gauge field, with the Wilson lines as Goldstone bosons.

  9. Effective field theory for magnetic compactifications

    Energy Technology Data Exchange (ETDEWEB)

    Buchmuller, Wilfried; Dierigl, Markus [Deutsches Elektronen-Synchrotron DESY,22607 Hamburg (Germany); Dudas, Emilian [Centre de Physique Théorique, École Polytechnique, CNRS, Université Paris-Saclay,F-91128 Palaiseau (France); Schweizer, Julian [Deutsches Elektronen-Synchrotron DESY,22607 Hamburg (Germany)

    2017-04-10

    Magnetic flux plays an important role in compactifications of field and string theories in two ways, it generates a multiplicity of chiral fermion zero modes and it can break supersymmetry. We derive the complete four-dimensional effective action for N=1 supersymmetric Abelian and non-Abelian gauge theories in six dimensions compactified on a torus with flux. The effective action contains the tower of charged states and it accounts for the mass spectrum of bosonic and fermionic fields as well as their level-dependent interactions. This allows us to compute quantum corrections to the mass and couplings of Wilson lines. We find that the one-loop corrections vanish, contrary to the case without flux. This can be traced back to the spontaneous breaking of symmetries of the six-dimensional theory by the background gauge field, with the Wilson lines as Goldstone bosons.

  10. Compactification of gauge theories and the gauge invariance of massive modes

    Energy Technology Data Exchange (ETDEWEB)

    Amorim, R.; Barcelos-Neto, J. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Inst. de Fisica

    2002-03-01

    We study the gauge invariance of the massive modes in the compactification of gauge theories from D = 5 to D = 4. We deal with Abelian gauge theories of rank one and two, and with non-Abelian ones of rank one. We show that Stueckelberg fields naturally appear in the compactification mechanism, contrarily to what usually occurs in literature where they are introduced by hand, as a trick, to render gauge invariance for massive theories. We also show that in the non-Abelian case they appear in a very different way when compared with their usual implementation in the non-Abelian Proca model. (author)

  11. Non-Abelian black holes in D=5 maximal gauged supergravity

    International Nuclear Information System (INIS)

    Cvetic, M.; Lue, H.; Pope, C. N.

    2010-01-01

    We investigate static non-Abelian black hole solutions of anti-de Sitter (AdS) Einstein-Yang-Mills-dilaton gravity, which is obtained as a consistent truncation of five-dimensional maximal gauged supergravity. If the dilaton is (consistently) set to zero, the remaining equations of motion, with a spherically-symmetric ansatz, may be derived from a superpotential. The associated first-order equations admit an explicit solution supported by a non-Abelian SU(2) gauge potential, which has a logarithmically growing mass term. In an extremal limit the horizon geometry becomes AdS 2 xS 3 . If the dilaton is also excited, the equations of motion cannot easily be solved explicitly, but we obtain the asymptotic form of the more general non-Abelian black holes in this case. An alternative consistent truncation, in which the Yang-Mills fields are set to zero, also admits a description in terms of a superpotential. This allows us to construct explicit wormhole solutions (neutral spherically-symmetric domain walls). These solutions may be generalized to dimensions other than five.

  12. Lessons from non-Abelian plasma instabilities in two spatial dimensions

    International Nuclear Information System (INIS)

    Arnold, Peter; Leang, P.-S.

    2007-01-01

    Plasma instabilities can play a fundamental role in quark-gluon plasma equilibration in the high energy (weak coupling) limit. Early simulations of the evolution of plasma instabilities in non-Abelian gauge theory, performed in one spatial dimension, found behavior qualitatively similar to traditional QED plasmas. Later simulations of the fully three-dimensional theory found different behavior, unlike traditional QED plasmas. To shed light on the origin of this difference, we study the intermediate case of two spatial dimensions. Depending on how the 'two-dimensional' theory is formulated, we can obtain either behavior

  13. Gauge theories of Yang-Mills vector fields coupled to antisymmetric tensor fields

    International Nuclear Information System (INIS)

    Anco, Stephen C.

    2003-01-01

    A non-Abelian class of massless/massive nonlinear gauge theories of Yang-Mills vector potentials coupled to Freedman-Townsend antisymmetric tensor potentials is constructed in four space-time dimensions. These theories involve an extended Freedman-Townsend-type coupling between the vector and tensor fields, and a Chern-Simons mass term with the addition of a Higgs-type coupling of the tensor fields to the vector fields in the massive case. Geometrical, field theoretic, and algebraic aspects of the theories are discussed in detail. In particular, the geometrical structure mixes and unifies features of Yang-Mills theory and Freedman-Townsend theory formulated in terms of Lie algebra valued curvatures and connections associated to the fields and nonlinear field strengths. The theories arise from a general determination of all possible geometrical nonlinear deformations of linear Abelian gauge theory for one-form fields and two-form fields with an Abelian Chern-Simons mass term in four dimensions. For this type of deformation (with typical assumptions on the allowed form considered for terms in the gauge symmetries and field equations), an explicit classification of deformation terms at first-order is obtained, and uniqueness of deformation terms at all higher orders is proven. This leads to a uniqueness result for the non-Abelian class of theories constructed here

  14. Quillen bundle and geometric prequantization of non-abelian ...

    Indian Academy of Sciences (India)

    In this paper we prequantize the moduli space of non-abelian vortices. We explicitly calculate the symplectic form arising from 2 metric and we construct a prequantum line bundle whose curvature is proportional to this symplectic form. The prequantum line bundle turns out to be Quillen's determinant line bundle with a ...

  15. Extended hubbard model with ring exchange: a route to a non-Abelian topological phase.

    Science.gov (United States)

    Freedman, Michael; Nayak, Chetan; Shtengel, Kirill

    2005-02-18

    We propose an extended Hubbard model on a 2D kagome lattice with an additional ring exchange term. The particles can be either bosons or spinless fermions. We analyze the model at the special filling fraction 1/6, where it is closely related to the quantum dimer model. We show how to arrive at an exactly soluble point whose ground state is the "d-isotopy" transition point into a stable phase with a certain type of non-Abelian topological order. Near the "special" values, d=2cos(pi/(k+2), this topological phase has anyonic excitations closely related to SU(2) Chern-Simons theory at level k.

  16. Understanding the physics of a possible non-Abelian fractional quantum hall effect state.

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Wei; Crawford, Matthew; Tallakulam, Madhu; Ross, Anthony Joseph, III

    2010-10-01

    We wish to present in this report experimental results from a one-year Senior Council Tier-1 LDRD project that focused on understanding the physics of a possible non-Abelian fractional quantum Hall effect state. We first give a general introduction to the quantum Hall effect, and then present the experimental results on the edge-state transport in a special fractional quantum Hall effect state at Landau level filling {nu} = 5/2 - a possible non-Abelian quantum Hall state. This state has been at the center of current basic research due to its potential applications in fault-resistant topological quantum computation. We will also describe the semiconductor 'Hall-bar' devices we used in this project. Electron physics in low dimensional systems has been one of the most exciting fields in condensed matter physics for many years. This is especially true of quantum Hall effect (QHE) physics, which has seen its intellectual wealth applied in and has influenced many seemingly unrelated fields, such as the black hole physics, where a fractional QHE-like phase has been identified. Two Nobel prizes have been awarded for discoveries of quantum Hall effects: in 1985 to von Klitzing for the discovery of integer QHE, and in 1998 to Tsui, Stormer, and Laughlin for the discovery of fractional QHE. Today, QH physics remains one of the most vibrant research fields, and many unexpected novel quantum states continue to be discovered and to surprise us, such as utilizing an exotic, non-Abelian FQHE state at {nu} = 5/2 for fault resistant topological computation. Below we give a briefly introduction of the quantum Hall physics.

  17. A hidden non-Abelian monopole in a 16-dimensional isotropic harmonic oscillator

    International Nuclear Information System (INIS)

    Le, Van-Hoang; Nguyen, Thanh-Son; Phan, Ngoc-Hung

    2009-01-01

    We suggest one variant of generalization of the Hurwitz transformation by adding seven extra variables that allow an inverse transformation to be obtained. Using this generalized transformation we establish the connection between the Schroedinger equation of a 16-dimensional isotropic harmonic oscillator and that of a nine-dimensional hydrogen-like atom in the field of a monopole described by a septet of potential vectors in a non-Abelian model of 28 operators. The explicit form of the potential vectors and all the commutation relations of the algebra are given./

  18. A hidden non-Abelian monopole in a 16-dimensional isotropic harmonic oscillator

    Energy Technology Data Exchange (ETDEWEB)

    Le, Van-Hoang; Nguyen, Thanh-Son; Phan, Ngoc-Hung [Department of Physics, HCMC University of Pedagogy, 280 An Duong Vuong, Ward 10, Dist. 5, Ho Chi Minh City (Viet Nam)

    2009-05-01

    We suggest one variant of generalization of the Hurwitz transformation by adding seven extra variables that allow an inverse transformation to be obtained. Using this generalized transformation we establish the connection between the Schroedinger equation of a 16-dimensional isotropic harmonic oscillator and that of a nine-dimensional hydrogen-like atom in the field of a monopole described by a septet of potential vectors in a non-Abelian model of 28 operators. The explicit form of the potential vectors and all the commutation relations of the algebra are given./.

  19. N = (2,0) self-dual non-Abelian tensor multiplet in D = 3 + 3 generates N = (1,1) self-dual systems in D = 2 + 2

    Science.gov (United States)

    Nishino, Hitoshi; Rajpoot, Subhash

    2018-03-01

    We formulate an N = (2 , 0) system in D = 3 + 3 dimensions consisting of a Yang-Mills (YM)-multiplet (ˆ μ ˆ IA, λˆI), a self-dual non-Abelian tensor multiplet (ˆ μ ˆ ν ˆ IB, χˆI ,φˆI), and an extra vector multiplet (C ˆ μ ˆ IC, ρˆI). We next perform the dimensional reductions of this system into D = 2 + 2, and obtain N = (1 , 1) systems with a self-dual YM-multiplet (AIμ ,λI), a self-dual tensor multiplet (BIμν , χI , φI), and an extra vector multiplet (CIμ , ρI). In D = 2 + 2, we reach two distinct theories: 'Theory-I' and 'Theory-II'. The former has the self-dual field-strength Hμν(+)I of CIμ already presented in our recent paper, while the latter has anti-self-dual field strength Hμν(-)I. As an application, we show that Theory-II actually generates supersymmetric-KdV equations in D = 1 + 1. Our result leads to a new conclusion that the D = 3 + 3 theory with non-Abelian tensor multiplet can be a 'Grand Master Theory' for self-dual multiplet and self-dual YM-multiplet in D = 2 + 2, that in turn has been conjectured to be the 'Master Theory' for all supersymmetric integrable theories in D ≤ 3.

  20. Clifford algebra in finite quantum field theories

    International Nuclear Information System (INIS)

    Moser, M.

    1997-12-01

    We consider the most general power counting renormalizable and gauge invariant Lagrangean density L invariant with respect to some non-Abelian, compact, and semisimple gauge group G. The particle content of this quantum field theory consists of gauge vector bosons, real scalar bosons, fermions, and ghost fields. We assume that the ultimate grand unified theory needs no cutoff. This yields so-called finiteness conditions, resulting from the demand for finite physical quantities calculated by the bare Lagrangean. In lower loop order, necessary conditions for finiteness are thus vanishing beta functions for dimensionless couplings. The complexity of the finiteness conditions for a general quantum field theory makes the discussion of non-supersymmetric theories rather cumbersome. Recently, the F = 1 class of finite quantum field theories has been proposed embracing all supersymmetric theories. A special type of F = 1 theories proposed turns out to have Yukawa couplings which are equivalent to generators of a Clifford algebra representation. These algebraic structures are remarkable all the more than in the context of a well-known conjecture which states that finiteness is maybe related to global symmetries (such as supersymmetry) of the Lagrangean density. We can prove that supersymmetric theories can never be of this Clifford-type. It turns out that these Clifford algebra representations found recently are a consequence of certain invariances of the finiteness conditions resulting from a vanishing of the renormalization group β-function for the Yukawa couplings. We are able to exclude almost all such Clifford-like theories. (author)

  1. Non-Abelian clouds around Reissner-Nordström black holes: The existence line

    Science.gov (United States)

    Radu, Eugen; Tchrakian, D. H.; Yang, Yisong

    2016-06-01

    A known feature of electrically charged Reissner-Nordström-anti-de Sitter planar black holes is that they can become unstable when considered as solutions of Einstein-Yang-Mills theory. The mechanism for this is that the linearized Yang-Mills equations in the background of the Reissner-Nordström (RN) black holes possess a normalizable zero mode, resulting in non-Abelian (nA) magnetic clouds near the horizon. In this work we show that the same pattern may occur also for asymptotically flat RN black holes. Different from the anti-de Sitter case, in the Minkowskian background the prerequisites for the existence of the nA clouds are (i) a large enough gauge group, and (ii) the presence of some extra interaction terms in the matter Lagrangian. To illustrate this mechanism we present two specific examples, one in four- and the other in five-dimensional asymptotically flat spacetime. In the first case, we augment the usual S U (3 ) Yang-Mills Lagrangian with a higher-order (quartic) curvature term, while for the second one we add the Chern-Simons density to the S O (6 ) Yang-Mills system. In both cases, an Abelian gauge symmetry is spontaneously broken near a RN black hole horizon with the appearance of a condensate of nA gauge fields. In addition to these two examples, we review the corresponding picture for anti-de Sitter black holes. All these solutions are studied both analytically and numerically, existence proofs being provided for nA clouds in the background of RN black holes. The proofs use shooting techniques which are suggested by and in turn offer insights for our numerical methods. They indicate that, for a black hole of given mass, appropriate electric charge values are required to ensure the existence of solutions interpolating desired boundary behavior at the horizons and spatial infinity.

  2. Anomaly cancelation in field theory and F-theory on a circle

    Science.gov (United States)

    Grimm, Thomas W.; Kapfer, Andreas

    2016-05-01

    We study the manifestation of local gauge anomalies of four- and six-dimensional field theories in the lower-dimensional Kaluza-Klein theory obtained after circle compactification. We identify a convenient set of transformations acting on the whole tower of massless and massive states and investigate their action on the low-energy effective theories in the Coulomb branch. The maps employ higher-dimensional large gauge transformations and precisely yield the anomaly cancelation conditions when acting on the one-loop induced Chern-Simons terms in the three- and five-dimensional effective theory. The arising symmetries are argued to play a key role in the study of the M-theory to F-theory limit on Calabi-Yau manifolds. For example, using the fact that all fully resolved F-theory geometries inducing multiple Abelian gauge groups or non-Abelian groups admit a certain set of symmetries, we are able to generally show the cancelation of pure Abelian or pure non-Abelian anomalies in these models.

  3. Anomaly cancelation in field theory and F-theory on a circle

    Energy Technology Data Exchange (ETDEWEB)

    Grimm, Thomas W.; Kapfer, Andreas [Max-Planck-Institut für Physik,Föhringer Ring 6, 80805 Munich (Germany)

    2016-05-17

    We study the manifestation of local gauge anomalies of four- and six-dimensional field theories in the lower-dimensional Kaluza-Klein theory obtained after circle compactification. We identify a convenient set of transformations acting on the whole tower of massless and massive states and investigate their action on the low-energy effective theories in the Coulomb branch. The maps employ higher-dimensional large gauge transformations and precisely yield the anomaly cancelation conditions when acting on the one-loop induced Chern-Simons terms in the three- and five-dimensional effective theory. The arising symmetries are argued to play a key role in the study of the M-theory to F-theory limit on Calabi-Yau manifolds. For example, using the fact that all fully resolved F-theory geometries inducing multiple Abelian gauge groups or non-Abelian groups admit a certain set of symmetries, we are able to generally show the cancelation of pure Abelian or pure non-Abelian anomalies in these models.

  4. Index theorem for non-supersymmetric fermions coupled to a non-Abelian string and electric charge quantization

    Science.gov (United States)

    Shifman, M.; Yung, A.

    2018-03-01

    Non-Abelian strings are considered in non-supersymmetric theories with fermions in various appropriate representations of the gauge group U(N). We derive the electric charge quantization conditions and the index theorems counting fermion zero modes in the string background both for the left-handed and right-handed fermions. In both cases we observe a non-trivial N dependence.

  5. Field theories with multiple fermionic excitations

    International Nuclear Information System (INIS)

    Crawford, J.P.

    1978-01-01

    The reason for the existence of the muon has been an enigma since its discovery. Since that time there has been a continuing proliferation of elementary particles. It is proposed that this proliferation of leptons and quarks is comprehensible if there are only four fundamental particles, the leptons ν/sub e/ and e - , and the quarks u and d. All other leptons and quarks are imagined to be excited states of these four fundamental entities. Attention is restricted to the charged leptons and the electromagnetic interactions only. A detailed study of a field theory in which there is only one fundamental charged fermionic field having two (or more) excitations is made. When the electromagnetic interactions are introduced and the theory is second quantized, under certain conditions this theory reproduces the S matrix obtained from usual OED. In this case no electromagnetic transitions are allowed. A leptonic charge operator is defined and a superselection rule for this leptonic charge is found. Unfortunately, the mass spectrum cannot be obtained. This theory has many renormalizable generalizations including non-abelian gauge theories, Yukawa-type theories, and Fermi-type theories. Under certain circumstances the Yukawa- and Fermi-type theories are finite in perturbation theory. It is concluded that there are no fundamental objections to having fermionic fields with more than one excitation

  6. arXiv Global $SU(2)_L \\otimes$BRST symmetry and its LSS theorem: Ward-Takahashi identities governing Green's functions, on-shell T-Matrix elements, and $V_{eff}$, in the scalar-sector of certain spontaneously broken non-Abelian gauge theories

    CERN Document Server

    Güngör, Özenç; Starkman, Glenn D.; Stora, Raymond

    This work is dedicated to the memory of Raymond Stora (1930-2015). $SU(2)_L$ is the simplest spontaneous symmetry breaking (SSB) non-Abelian gauge theory: a complex scalar doublet $\\phi =\\frac{1}{\\sqrt{2}}\\begin{bmatrix}H+i\\pi_3 -\\pi_2 + i\\pi_1\\end{bmatrix}\\equiv \\frac{1}{\\sqrt{2}}\\tilde{H}e^{2i\\tilde{t}\\cdot\\tilde{\\vec{\\pi}}/}\\begin{bmatrix}1 0\\end{bmatrix}$ and a vector $\\vec{W}^\\mu$. In Landau gauge, $\\vec{W}^\\mu$ is transverse, $\\vec{\\tilde{\\pi}}$ are massless derivatively coupled Nambu-Goldstone bosons (NGB). A global shift symmetry enforces $m^{2}_{\\tilde{\\pi}}=0$. We observe that on-shell T-matrix elements of physical states ${\\vec W}^\\mu$,$\\phi$ are independent of global $SU(2)_{L}$ transformations, and that the associated global current is exactly conserved for amplitudes of physical states. We identify two towers of "1-soft-pion" global Ward-Takahashi Identities (WTI), which govern the $\\phi$-sector, and represent a new global symmetry which we call $SU(2)_L\\otimes$BRST, a symmetry not of the Lagran...

  7. arXiv Global $SU(2)_L \\otimes$BRST symmetry and its LSS theorem: Ward-Takahashi identities governing Green's functions, on-shell T-Matrix elements, and $V_{eff}$, in the scalar-sector of certain spontaneously broken non-Abelian gauge theories

    CERN Document Server

    Güngör, Özenç; Starkman, Glenn D.; Stora, Raymond

    This work is dedicated to the memory of Raymond Stora (1930-2015). $SU(2)_L$ is the simplest spontaneous symmetry breaking (SSB) non-Abelian gauge theory: a complex scalar doublet $\\phi=\\frac{1}{\\sqrt{2}}\\begin{bmatrix}H+i\\pi_3-\\pi_2 +i\\pi_1\\end{bmatrix}\\equiv\\frac{1}{\\sqrt{2}}\\tilde{H}e^{2i\\tilde{t}\\cdot\\tilde{\\vec{\\pi}}/}\\begin{bmatrix}10\\end{bmatrix}$ and a vector $\\vec{W}^\\mu$. In Landau gauge, $\\vec{W}^\\mu$ is transverse, $\\vec{\\tilde{\\pi}}$ are massless derivatively coupled Nambu-Goldstone bosons (NGB). A global shift symmetry enforces $m^{2}_{\\tilde{\\pi}}=0$. We observe that on-shell T-matrix elements of physical states $\\vec{W}^\\mu$,$\\phi$ are independent of global $SU(2)_{L}$ transformations, and the associated global current is exactly conserved for amplitudes of physical states. We identify two towers of "1-soft-pion" global Ward-Takahashi Identities (WTI), which govern the $\\phi$-sector, and represent a new global symmetry, $SU(2)_L\\otimes$BRST, a symmetry not of the Lagrangian but of the physical...

  8. Pure spinors as auxiliary fields in the ten-dimensional supersymmetric Yang-Mills theory

    International Nuclear Information System (INIS)

    Nilsson, B.E.W.

    1986-01-01

    A new way of introducing auxiliary fields into the ten-dimensional supersymmetric Yang-Mills theory is proposed. The auxiliary fields are commuting 'pure spinors' and constitute a non-linear realisation of the Lorentz group. This invalidates previous no-go theorems concerning the possibility of going off-shell in this theory. There seems to be a close relation between pure spinors and the concepts usually used in twistor theory. The non-Abelian theory can be constructed for all groups having pseudo-real representations. (author)

  9. Non-Abelian electric-magnetic duality with supersymmetry in 4D and 10D

    Science.gov (United States)

    Nishino, Hitoshi; Rajpoot, Subhash

    2015-10-01

    We present electric-magnetic (Hodge) duality formulation for non-Abelian gauge groups with N =1 supersymmetry in 3 +1 (4D) dimensions. Our system consists of three multiplets: (i) A super-Yang-Mills vector multiplet (YMVM) (Aμ I,λI) , (ii) a dual vector multiplet (DVM) (Bμ I,χI) , and (iii) an unphysical tensor multiplet (TM) (Cμν I,ρI,φI) , with the index I for adjoint representation. The multiplets YMVM and DVM are dual to each other like: Gμν I=(1 /2 )ɛμν ρ σFρσ I . The TM is unphysical, but still plays an important role for establishing the total consistency of the system, based on recently developed tensor-hierarchy formulation. We also apply this technique to non-Abelian electric-magnetic duality in 9 +1 (10D) dimensions. The extra bosonic auxiliary field Kμ1⋯μ6 in 10D is shown to play an important role for the closure of supersymmetry on fields.

  10. Non-abelian bosonization without Wess-Zumino terms. Pt. 1

    International Nuclear Information System (INIS)

    Rajeev, S.G.

    1989-01-01

    It is conjectured that the non-linear sigma-model without Wess-Zumino terms is equivalent as a quantum theory to the non-abelian massless Thirring model. However, the standard (Sugawara) current algebra of the non-linear model is not isomorphic to that of the fermionic theory. A new current algebra formalism is proposed, which depends on a parameter k. As k → ∞ it reduces to the Sugawara formalism. The new current algebra is isomorphic to the fermionic one, being the direct sum of two Kac-Moody algebras with opposite central terms. In the quantum theory, k (which is the level number) has to be an integer. The new formalism is shown to preserve Poincare and conformal invariance classically. The new current algebra is derived canonically and a new action principle for the non-linear model is proposed. (orig.)

  11. Top quark asymmetry from a non-Abelian horizontal symmetry

    CERN Document Server

    Jung, Sunghoon; Wells, James D

    2011-01-01

    Motivated by the persistence of a large measured top quark forward-backward asymmetry at the Tevatron, we examine a model of non-Abelian flavor gauge symmetry. The exchange of the gauge bosons in the $t$-channel can give a large $\\Afb$ due to the forward Rutherford scattering peak. We address generic constraints on non-Abelian $t$-channel physics models including flavor diagonal resonances and potentially dangerous contributions to inclusive top pair cross sections. We caution on the general difficulty of comparing theoretical predictions for top quark signals to the existing experimental results due to potentially important acceptance effects. The first signature at the Large Hadron Collider can be a large inclusive top pair cross section, or like-sign dilepton events, although the latter signal is much smaller than in Abelian models. Deviations of the invariant mass distributions at the LHC will also be promising signatures. A more direct consistency check of the Tevatron asymmetry through the LHC asymmetry...

  12. Universally leptophilic dark matter from non-Abelian discrete symmetry

    Energy Technology Data Exchange (ETDEWEB)

    Haba, Naoyuki [Department of Physics, Osaka University, Toyonaka 560-0801 (Japan); Kajiyama, Yuji [National Institute of Chemical Physics and Biophysics, Ravala 10, Tallinn 10143 (Estonia); Matsumoto, Shigeki [Department of Physics, University of Toyama, Toyama 930-8555 (Japan); IPMU, University of Tokyo, Kashiwa 277-8583 (Japan); Okada, Hiroshi, E-mail: HOkada@Bue.edu.e [Centre for Theoretical Physics, British University in Egypt, El Sherouk City, Postal No. 11837, P.O. Box 43 (Egypt); Yoshioka, Koichi [Department of Physics, Kyoto University, Kyoto 606-8502 (Japan)

    2011-01-17

    The positron anomaly recently reported by the cosmic-ray measurements can be explained by the decaying dark matter scenario, where it decays mainly into leptons with the lifetime of O(10{sup 26}) s. When the dark matter is a fermionic particle, the lifetime of this order is known to be obtained by a dimension 6 operator suppressed by the unification scale ({approx}10{sup 16} GeV), while such decay operators do not necessarily involve only leptons. In addition, the scenario would be spoiled if there exist lower-dimensional operators inducing the dark matter decay. We show in this Letter that a single non-Abelian discrete symmetry such as A{sub 4} is possible to prohibit all such harmful (non-leptonically coupled and lower-dimensional) operators. Moreover, the dark matter decays into charged leptons in a flavor-blind fashion due to the non-Abelian flavor symmetry, which results in perfect agreements not only with the PAMELA data but also with the latest Fermi-LAT data reported very recently. We also discuss some relevance between the discrete symmetry and neutrino physics.

  13. Error Correction for Non-Abelian Topological Quantum Computation

    Directory of Open Access Journals (Sweden)

    James R. Wootton

    2014-03-01

    Full Text Available The possibility of quantum computation using non-Abelian anyons has been considered for over a decade. However, the question of how to obtain and process information about what errors have occurred in order to negate their effects has not yet been considered. This is in stark contrast with quantum computation proposals for Abelian anyons, for which decoding algorithms have been tailor-made for many topological error-correcting codes and error models. Here, we address this issue by considering the properties of non-Abelian error correction, in general. We also choose a specific anyon model and error model to probe the problem in more detail. The anyon model is the charge submodel of D(S_{3}. This shares many properties with important models such as the Fibonacci anyons, making our method more generally applicable. The error model is a straightforward generalization of those used in the case of Abelian anyons for initial benchmarking of error correction methods. It is found that error correction is possible under a threshold value of 7% for the total probability of an error on each physical spin. This is remarkably comparable with the thresholds for Abelian models.

  14. Stable monopole and dyon solutions in the einstein-yang-mills theory in asymptotically anti-de sitter space

    Science.gov (United States)

    Bjoraker; Hosotani

    2000-02-28

    A continuum of new monopole and dyon solutions in the Einstein-Yang-Mills theory in asymptotically anti-de Sitter space are found. They are regular everywhere and specified by their mass and their non-Abelian electric and magnetic charges. A class of monopole solutions which have no node in non-Abelian magnetic fields is shown to be stable against spherically symmetric linear perturbations.

  15. Deformation of the cubic open string field theory

    International Nuclear Information System (INIS)

    Lee, Taejin

    2017-01-01

    We study a consistent deformation of the cubic open bosonic string theory in such a way that the non-planar world sheet diagrams of the perturbative string theory are mapped onto their equivalent planar diagrams of the light-cone string field theory with some length parameters fixed. An explicit evaluation of the cubic string vertex in the zero-slope limit yields the correct relationship between the string coupling constant and the Yang–Mills coupling constant. The deformed cubic open string field theory is shown to produce the non-Abelian Yang–Mills action in the zero-slope limit if it is defined on multiple D-branes. Applying the consistent deformation systematically to multi-string world sheet diagrams, we may be able to calculate scattering amplitudes with an arbitrary number of external open strings.

  16. Deformation of the cubic open string field theory

    Science.gov (United States)

    Lee, Taejin

    2017-05-01

    We study a consistent deformation of the cubic open bosonic string theory in such a way that the non-planar world sheet diagrams of the perturbative string theory are mapped onto their equivalent planar diagrams of the light-cone string field theory with some length parameters fixed. An explicit evaluation of the cubic string vertex in the zero-slope limit yields the correct relationship between the string coupling constant and the Yang-Mills coupling constant. The deformed cubic open string field theory is shown to produce the non-Abelian Yang-Mills action in the zero-slope limit if it is defined on multiple D-branes. Applying the consistent deformation systematically to multi-string world sheet diagrams, we may be able to calculate scattering amplitudes with an arbitrary number of external open strings.

  17. Deformation of the cubic open string field theory

    Directory of Open Access Journals (Sweden)

    Taejin Lee

    2017-05-01

    Full Text Available We study a consistent deformation of the cubic open bosonic string theory in such a way that the non-planar world sheet diagrams of the perturbative string theory are mapped onto their equivalent planar diagrams of the light-cone string field theory with some length parameters fixed. An explicit evaluation of the cubic string vertex in the zero-slope limit yields the correct relationship between the string coupling constant and the Yang–Mills coupling constant. The deformed cubic open string field theory is shown to produce the non-Abelian Yang–Mills action in the zero-slope limit if it is defined on multiple D-branes. Applying the consistent deformation systematically to multi-string world sheet diagrams, we may be able to calculate scattering amplitudes with an arbitrary number of external open strings.

  18. Deformation of the cubic open string field theory

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Taejin, E-mail: taejin@kangwon.ac.kr

    2017-05-10

    We study a consistent deformation of the cubic open bosonic string theory in such a way that the non-planar world sheet diagrams of the perturbative string theory are mapped onto their equivalent planar diagrams of the light-cone string field theory with some length parameters fixed. An explicit evaluation of the cubic string vertex in the zero-slope limit yields the correct relationship between the string coupling constant and the Yang–Mills coupling constant. The deformed cubic open string field theory is shown to produce the non-Abelian Yang–Mills action in the zero-slope limit if it is defined on multiple D-branes. Applying the consistent deformation systematically to multi-string world sheet diagrams, we may be able to calculate scattering amplitudes with an arbitrary number of external open strings.

  19. Twisted conformal field theories and Morita equivalence

    Energy Technology Data Exchange (ETDEWEB)

    Marotta, Vincenzo [Dipartimento di Scienze Fisiche, Universita di Napoli ' Federico II' and INFN, Sezione di Napoli, Compl. universitario M. Sant' Angelo, Via Cinthia, 80126 Napoli (Italy); Naddeo, Adele [CNISM, Unita di Ricerca di Salerno and Dipartimento di Fisica ' E.R. Caianiello' , Universita degli Studi di Salerno, Via Salvador Allende, 84081 Baronissi (Italy); Dipartimento di Scienze Fisiche, Universita di Napoli ' Federico II' , Compl. universitario M. Sant' Angelo, Via Cinthia, 80126 Napoli (Italy)], E-mail: adelenaddeo@yahoo.it

    2009-04-01

    The Morita equivalence for field theories on noncommutative two-tori is analysed in detail for rational values of the noncommutativity parameter {theta} (in appropriate units): an isomorphism is established between an Abelian noncommutative field theory (NCFT) and a non-Abelian theory of twisted fields on ordinary space. We focus on a particular conformal field theory (CFT), the one obtained by means of the m-reduction procedure [V. Marotta, J. Phys. A 26 (1993) 3481; V. Marotta, Mod. Phys. Lett. A 13 (1998) 853; V. Marotta, Nucl. Phys. B 527 (1998) 717; V. Marotta, A. Sciarrino, Mod. Phys. Lett. A 13 (1998) 2863], and show that it is the Morita equivalent of a NCFT. Finally, the whole m-reduction procedure is shown to be the image in the ordinary space of the Morita duality. An application to the physics of a quantum Hall fluid at Jain fillings {nu}=m/(2pm+1) is explicitly discussed in order to further elucidate such a correspondence and to clarify its role in the physics of strongly correlated systems. A new picture emerges, which is very different from the existing relationships between noncommutativity and many body systems [A.P. Polychronakos, arXiv: 0706.1095].

  20. Dressed scalar propagator in a non-Abelian background from the worldline formalism

    Science.gov (United States)

    Ahmadiniaz, Naser; Bastianelli, Fiorenzo; Corradini, Olindo

    2016-01-01

    We study the propagator of a colored scalar particle in the background of a non-Abelian gauge field using the worldline formalism. It is obtained by considering the open worldline of a scalar particle with extra degrees of freedom needed to take into account the color charge of the particle, which we choose to be in the fundamental representation of the gauge group. Specializing the external gauge field to be given by a sum of plane waves, i.e. a sum of external gluons, we produce a master formula for the scalar propagator with an arbitrary number of gluons directly attached to the scalar line, akin to similar formulas derived in the literature for the case of the scalar particle performing a loop. Our worldline description produces at the same time the situation in which the particle has a color charge given by an arbitrarily chosen symmetric or antisymmetric tensor product of the fundamental.

  1. Non-perturbative methodologies for low-dimensional strongly-correlated systems: From non-Abelian bosonization to truncated spectrum methods

    Science.gov (United States)

    James, Andrew J. A.; Konik, Robert M.; Lecheminant, Philippe; Robinson, Neil J.; Tsvelik, Alexei M.

    2018-04-01

    We review two important non-perturbative approaches for extracting the physics of low-dimensional strongly correlated quantum systems. Firstly, we start by providing a comprehensive review of non-Abelian bosonization. This includes an introduction to the basic elements of conformal field theory as applied to systems with a current algebra, and we orient the reader by presenting a number of applications of non-Abelian bosonization to models with large symmetries. We then tie this technique into recent advances in the ability of cold atomic systems to realize complex symmetries. Secondly, we discuss truncated spectrum methods for the numerical study of systems in one and two dimensions. For one-dimensional systems we provide the reader with considerable insight into the methodology by reviewing canonical applications of the technique to the Ising model (and its variants) and the sine-Gordon model. Following this we review recent work on the development of renormalization groups, both numerical and analytical, that alleviate the effects of truncating the spectrum. Using these technologies, we consider a number of applications to one-dimensional systems: properties of carbon nanotubes, quenches in the Lieb–Liniger model, 1  +  1D quantum chromodynamics, as well as Landau–Ginzburg theories. In the final part we move our attention to consider truncated spectrum methods applied to two-dimensional systems. This involves combining truncated spectrum methods with matrix product state algorithms. We describe applications of this method to two-dimensional systems of free fermions and the quantum Ising model, including their non-equilibrium dynamics.

  2. [Studies in quantum field theory: Progress report, April 1, 1991--March 31, 1992

    International Nuclear Information System (INIS)

    Bender, C.M.

    1992-01-01

    Professors Bender, Bernard, and Shrauner, Assistant Professors Ogilvie and Goltermann, Research Assistant Professors Visser and Petcher, and Research Associate Rivas are currently conducting research in many areas of high energy theoretical and mathematical physics. These areas include: lattice gauge calculations of masses and weak matrix elements; strong-coupling approximation; low-energy effective field theories; classical solutions of non-Abelian gauge theories; mean-field approximation in quantum field theory; path integral and coherent state representations in quantum field theory; the nature of perturbation theory in large order; quark condensation in QCD; chiral fermion theories on the lattice; the 1/N expansion in quantum field theory; effective potential and action in quantum field theories, including QCD; studies of the early universe and inflation; quantum gravity. This work is described in detail in the body of this proposal

  3. (Studies in quantum field theory: Progress report, April 1, 1991--March 31, 1992)

    Energy Technology Data Exchange (ETDEWEB)

    Bender, C M

    1992-01-01

    Professors Bender, Bernard, and Shrauner, Assistant Professors Ogilvie and Goltermann, Research Assistant Professors Visser and Petcher, and Research Associate Rivas are currently conducting research in many areas of high energy theoretical and mathematical physics. These areas include: lattice gauge calculations of masses and weak matrix elements; strong-coupling approximation; low-energy effective field theories; classical solutions of non-Abelian gauge theories; mean-field approximation in quantum field theory; path integral and coherent state representations in quantum field theory; the nature of perturbation theory in large order; quark condensation in QCD; chiral fermion theories on the lattice; the 1/N expansion in quantum field theory; effective potential and action in quantum field theories, including QCD; studies of the early universe and inflation; quantum gravity. This work is described in detail in the body of this proposal.

  4. Non-abelian geometrical quantum gate operation in an ultracold strontium gas

    Science.gov (United States)

    Leroux, Frederic

    The work developed in this PhD thesis is about geometric operation on a single qubit. If the external control parameters vary slowly, the quantum system evolves adiabatically in a sub-space composed of two degenerate eigenstates. After a closed loop in the space of the external parameters, the qubit acquires a geometrical rotation, which can be described by a unitary matrix in the Hilbert space of the two-level system. To the geometric rotation corresponds a non-Abelian gauge field. In this work, the qubit and the adiabatic geometrical quantum gates are implemented on a cold gas of atomic Strontium 87, trapped and cooled at the vicinity of the recoil temperature. The internal Hilbert space of the cold atoms has for basis the dressed states issued from the atom-light interaction of three lasers within a tripod configuration.

  5. Numerical studies of gauge field theories

    International Nuclear Information System (INIS)

    Creutz, M.

    1981-06-01

    Monte Carlo simulation of statistical systems is a well established technique of the condensed matter physicist. In the last few years, particle theorists have rediscovered this method and are having a marvelous time applying it to quantized gauge field theories. The main result has been strong numerical evidence that the standard SU(3) non-Abelian gauge theory of the strong interaction is capable of simultaneously confining quarks into the physical hadrons and exhibiting asymptotic freedom, the phenomenon of quark interactions being small at short distances. In four dimensions, confinement is a non-perturbative phenomenon. Essentially all models of confinement tie widely separated quarks together with strings of gauge field flux. This gives rise to a linear potential at long distances. A Monte Carlo program generates a sequence of field configuration by a series of random changes of the fields. The algorithm is so constructed that ultimately the probability density for finding any given configuration is proportional to the Boltzmann weighting. We bring our lattices into thermal equilibrium with a heat bath at a temperature specified by the coupling constant. Thus we do computer experiments with four-dimensional crystals stored in a computer memory. As the entire field configuration is stored, we have access to any correlation function desired. These lectures describe the kinds of experiments being done and the implications of these results for strong interaction physics

  6. Approaching conformality in non-Abelian gauge theories

    NARCIS (Netherlands)

    Nunes da Silva, Tiago Jose

    2016-01-01

    The Standard Model has been experimentally tested to a remarkable precision. Some questions, however, have still found no solution within its framework, and physicists look for possible solutions in extensions of it, a research area usually referred to as {it Beyond the Standard Model Physics}. This

  7. Supergravity and M-Theory

    NARCIS (Netherlands)

    de Wit, B.Q.P.J.; van Zalk, M.

    2009-01-01

    Supergravity provides the effective field theories for string compactifications. The deformation of the maximal supergravities by non-abelian gauge interactions is only possible for a restricted class of charges. Generically these ‘gaugings’ involve a hierarchy of p-form fields which belong to

  8. Non-Abelian strategies in quantum penny flip game

    Science.gov (United States)

    Mishima, Hiroaki

    2018-01-01

    In this paper, we formulate and analyze generalizations of the quantum penny flip game. In the penny flip game, one coin has two states, heads or tails, and two players apply alternating operations on the coin. In the original Meyer game, the first player is allowed to use quantum (i.e., non-commutative) operations, but the second player is still only allowed to use classical (i.e., commutative) operations. In our generalized games, both players are allowed to use non-commutative operations, with the second player being partially restricted in what operators they use. We show that even if the second player is allowed to use "phase-variable" operations, which are non-Abelian in general, the first player still has winning strategies. Furthermore, we show that even when the second player is allowed to choose one from two or more elements of the group U(2), the second player has winning strategies under certain conditions. These results suggest that there is often a method for restoring the quantum state disturbed by another agent.

  9. String-nets, single- and double-stranded quantum loop gases for non-Abelian anyons

    Energy Technology Data Exchange (ETDEWEB)

    Velenich, Andrea; Chamon, Claudio [Physics Department, Boston University, 590 Commonwealth Avenue, Boston, MA 02215 (United States); Wen Xiaogang, E-mail: velenich@bu.ed [Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02215 (United States)

    2010-04-30

    String-nets and quantum loop gases are two prominent microscopic lattice models to describe topological phases. String-net condensation can give rise to both Abelian and non-Abelian anyons, whereas loop condensation usually produces Abelian anyons. It has been proposed, however, that generalized quantum loop gases with non-orthogonal inner products could support non-Abelian anyons. We detail an exact mapping between the string-net and these generalized loop models and explain how the non-orthogonal products arise. We also introduce an equivalent loop model of double-stranded nets where quantum loops with an orthogonal inner product and local interactions supports non-Abelian Fibonacci anyons. Finally, we emphasize the origin of the sign problem in systems with non-Abelian excitations and its consequences on the complexity of their ground state wavefunctions. (fast track communication)

  10. Branes for Higgs phases and exact conformal field theories

    CERN Document Server

    Sfetsos, K

    1999-01-01

    We consider multicenter supergravity solutions corresponding to Higgs phases of supersymmetric Yang-Mills theories with Z_N symmetric vacuua. In certain energy regimes, we find a description in terms of a generalized wormhole solution that corresponds to the SL(2,R)/U(1) \\times SU(2)/U(1) exact conformal field theory. We show that U-dualities map these backgrounds to purely gravitational ones and comment on the relation to the black holes arising from intersecting D1 and D5 branes. We also discuss supersymmetric properties of the various solutions and the relation to 2-dim solitons, on flat space, of the reduced axion-dilaton-gravity equations. Finally, we address the problem of understanding other supergravity solutions from the multicenter ones. As prototype examples we use rotating D3 branes and NS5 and D5 branes associated to non-Abelian duals of 4-dim hyper-Kahler metrics with SO(3) isometry.

  11. Anisotropic shear viscosity of a strongly coupled non-Abelian plasma from magnetic branes

    Science.gov (United States)

    Critelli, R.; Finazzo, S. I.; Zaniboni, M.; Noronha, J.

    2014-09-01

    Recent estimates for the electromagnetic fields produced in the early stages of noncentral ultrarelativistic heavy ion collisions indicate the presence of magnetic fields B ˜O(0.1-15mπ2), where mπ is the pion mass. It is then of special interest to study the effects of strong (Abelian) magnetic fields on the transport coefficients of strongly coupled non-Abelian plasmas, such as the quark-gluon plasma formed in heavy ion collisions. In this paper we study the anisotropy in the shear viscosity induced by an external magnetic field in a strongly coupled N =4 super Yang-Mills (SYM) plasma. Due to the spatial anisotropy created by the magnetic field, the most general viscosity tensor of a magnetized plasma has five shear viscosity coefficients and two bulk viscosities. We use the holographic correspondence to evaluate two of the shear viscosities, η⊥≡ηxyxy (perpendicular to the magnetic field) and η∥≡ηxzxz=ηyzyz (parallel to the field). When B ≠0 the shear viscosity perpendicular to the field saturates the viscosity bound η⊥/s=1/(4π), while in the direction parallel to the field the bound is violated since η∥/s<1/(4π). However, the violation of the bound in the case of strongly coupled SYM is minimal even for the largest value of B that can be reached in heavy ion collisions.

  12. Covariant open bosonic string field theory on multiple D-branes in the proper-time gauge

    Science.gov (United States)

    Lee, Taejin

    2017-12-01

    We construct a covariant open bosonic string field theory on multiple D-branes, which reduces to a non-Abelian group Yang-Mills gauge theory in the zero-slope limit. Making use of the first quantized open bosonic string in the proper time gauge, we convert the string amplitudes given by the Polyakov path integrals on string world sheets into those of the second quantized theory. The world sheet diagrams generated by the constructed open string field theory are planar in contrast to those of the Witten's cubic string field theory. However, the constructed string field theory is yet equivalent to the Witten's cubic string field theory. Having obtained planar diagrams, we may adopt the light-cone string field theory technique to calculate the multi-string scattering amplitudes with an arbitrary number of external strings. We examine in detail the three-string vertex diagram and the effective four-string vertex diagrams generated perturbatively by the three-string vertex at tree level. In the zero-slope limit, the string scattering amplitudes are identified precisely as those of non-Abelian Yang-Mills gauge theory if the external states are chosen to be massless vector particles.

  13. L{sub ∞} algebras and field theory

    Energy Technology Data Exchange (ETDEWEB)

    Hohm, Olaf [Simons Center for Geometry and Physics, Stony Brook University, Stony Brook, NY (United States); Zwiebach, Barton [Center for Theoretical Physics, Massachusetts Institute of Technology, Cambridge, MA (United States)

    2017-03-15

    We review and develop the general properties of L{sub ∞} algebras focusing on the gauge structure of the associated field theories. Motivated by the L{sub ∞} homotopy Lie algebra of closed string field theory and the work of Roytenberg and Weinstein describing the Courant bracket in this language we investigate the L{sub ∞} structure of general gauge invariant perturbative field theories. We sketch such formulations for non-abelian gauge theories, Einstein gravity, and for double field theory. We find that there is an L{sub ∞} algebra for the gauge structure and a larger one for the full interacting field theory. Theories where the gauge structure is a strict Lie algebra often require the full L{sub ∞} algebra for the interacting theory. The analysis suggests that L{sub ∞} algebras provide a classification of perturbative gauge invariant classical field theories. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  14. A non-Abelian SO(8) monopole as generalization of Dirac-Yang monopoles for a 9-dimensional space

    International Nuclear Information System (INIS)

    Le, Van-Hoang; Nguyen, Thanh-Son

    2011-01-01

    We establish an explicit form of a non-Abelian SO(8) monopole in a 9-dimensional space and show that it is indeed a direct generalization of Dirac and Yang monopoles. Using the generalized Hurwitz transformation, we have found a connection between a 16-dimensional harmonic oscillator and a 9-dimensional hydrogenlike atom in the field of the SO(8) monopole (MICZ-Kepler problem). Using the built connection the group of dynamical symmetry of the 9-dimensional MICZ-Kepler problem is found as SO(10, 2).

  15. Some Global Aspects of Duality is String Theory

    CERN Document Server

    Alvarez, Enrique; Barbón, José L F; Lozano, Y

    1994-01-01

    We explore some of the global aspects of duality transformations in String Theory and Field Theory. We analyze in some detail the equivalence of dual models corresponding to different topologies at the level of the partition function and in terms of the operator correspondence for abelian duality. We analyze the behavior of the cosmological constant under these transformations. We also explore several examples of non-abelian duality where the classical background interpretation can be maintained for the original and the dual theories. In particular we construct a non-abelian dual of $SL(2,R)$ which turns out to be a three-dimensional black hole

  16. N=(2,0 self-dual non-Abelian tensor multiplet in D=3+3 generates N=(1,1 self-dual systems in D=2+2

    Directory of Open Access Journals (Sweden)

    Hitoshi Nishino

    2018-03-01

    Full Text Available We formulate an N=(2,0 system in D=3+3 dimensions consisting of a Yang–Mills (YM-multiplet (AˆμˆI,λˆI, a self-dual non-Abelian tensor multiplet (BˆμˆνˆI,χˆI,φˆI, and an extra vector multiplet (CˆμˆI,ρˆI. We next perform the dimensional reductions of this system into D=2+2, and obtain N=(1,1 systems with a self-dual YM-multiplet (AμI,λI, a self-dual tensor multiplet (BμνI,χI,φI, and an extra vector multiplet (CμI,ρI. In D=2+2, we reach two distinct theories: ‘Theory-I’ and ‘Theory-II’. The former has the self-dual field-strength Hμν(+I of CμI already presented in our recent paper, while the latter has anti-self-dual field strength Hμν(−I. As an application, we show that Theory-II actually generates supersymmetric-KdV equations in D=1+1. Our result leads to a new conclusion that the D=3+3 theory with non-Abelian tensor multiplet can be a ‘Grand Master Theory’ for self-dual multiplet and self-dual YM-multiplet in D=2+2, that in turn has been conjectured to be the ‘Master Theory’ for all supersymmetric integrable theories in D≤3.

  17. Theory and phenomenology of strong and weak interaction high energy physics. Technical progress report, May 1, 1985-April 30, 1986

    International Nuclear Information System (INIS)

    Thews, R.L.; Scadron, M.D.; Patrascioiu, A.; Sucipto, E.

    1986-01-01

    Progress is reported in these areas: dynamical quark mass in QCD; quark s-d self energy in QFD; theory of nonleptonic weak decays; decays of heavy-quark mesons; quarks in nuclei; nonperturbative effects in non-abelian quantum field theory; whether perturbation theory is the asymptotic expansion in lattice gauge theories; and expanding in the gradient at weak coupling. 16 refs

  18. Self-interacting dark matter from a non-Abelian hidden sector

    Science.gov (United States)

    Boddy, Kimberly K.; Feng, Jonathan L.; Kaplinghat, Manoj; Tait, Tim M. P.

    2014-06-01

    There is strong evidence in favor of the idea that dark matter is self interacting, with the cross section-to-mass ratio σ/m ˜1 cm2/g ˜1 barn/GeV. We show that viable models of dark matter with this large cross section are straightforwardly realized with non-Abelian hidden sectors. In the simplest of such models, the hidden sector is a pure gauge theory, and the dark matter is composed of hidden glueballs with a mass around 100 MeV. Alternatively, the hidden sector may be a supersymmetric pure gauge theory with a ˜10 TeV gluino thermal relic. In this case, the dark matter is largely composed of glueballinos that strongly self interact through the exchange of light glueballs. We present a unified framework that realizes both of these possibilities in anomaly-mediated supersymmetry breaking, where, depending on a few model parameters, the dark matter may be composed of hidden glueballinos, hidden glueballs, or a mixture of the two. These models provide simple examples of multicomponent dark matter, have interesting implications for particle physics and cosmology, and include cases where a subdominant component of dark matter may be extremely strongly self interacting, with interesting astrophysical consequences.

  19. Dimensional Reduction Over the Quantum Sphere and Non-Abelian q-Vortices

    Science.gov (United States)

    Landi, Giovanni; Szabo, Richard J.

    2011-12-01

    We extend equivariant dimensional reduction techniques to the case of quantum spaces which are the product of a Kähler manifold M with the quantum two-sphere. We work out the reduction of bundles which are equivariant under the natural action of the quantum group SU q (2), and also of invariant gauge connections on these bundles. The reduction of Yang-Mills gauge theory on the product space leads to a q-deformation of the usual quiver gauge theories on M. We formulate generalized instanton equations on the quantum space and show that they correspond to q-deformations of the usual holomorphic quiver chain vortex equations on M. We study some topological stability conditions for the existence of solutions to these equations, and demonstrate that the corresponding vacuum moduli spaces are generally better behaved than their undeformed counterparts, but much more constrained by the q-deformation. We work out several explicit examples, including new examples of non-abelian vortices on Riemann surfaces, and q-deformations of instantons whose moduli spaces admit the standard hyper-Kähler quotient construction.

  20. Non-Abelian fermionization and fractional quantum Hall transitions

    Science.gov (United States)

    Hui, Aaron; Mulligan, Michael; Kim, Eun-Ah

    2018-02-01

    There has been a recent surge of interest in dualities relating theories of Chern-Simons gauge fields coupled to either bosons or fermions within the condensed matter community, particularly in the context of topological insulators and the half-filled Landau level. Here, we study the application of one such duality to the long-standing problem of quantum Hall interplateaux transitions. The key motivating experimental observations are the anomalously large value of the correlation length exponent ν ≈2.3 and that ν is observed to be superuniversal, i.e., the same in the vicinity of distinct critical points [Sondhi et al., Rev. Mod. Phys. 69, 315 (1997), 10.1103/RevModPhys.69.315]. Duality motivates effective descriptions for a fractional quantum Hall plateau transition involving a Chern-Simons field with U (Nc) gauge group coupled to Nf=1 fermion. We study one class of theories in a controlled limit where Nf≫Nc and calculate ν to leading nontrivial order in the absence of disorder. Although these theories do not yield an anomalously large exponent ν within the large Nf≫Nc expansion, they do offer a new parameter space of theories that is apparently different from prior works involving Abelian Chern-Simons gauge fields [Wen and Wu, Phys. Rev. Lett. 70, 1501 (1993), 10.1103/PhysRevLett.70.1501; Chen et al., Phys. Rev. B 48, 13749 (1993), 10.1103/PhysRevB.48.13749].

  1. A magnetic instability of the non-Abelian Sakai-Sugimoto model

    International Nuclear Information System (INIS)

    Callebaut, Nele; Dudal, David

    2014-01-01

    In this follow-up paper of http://dx.doi.org/10.1007/JHEP03(2013)033 we further discuss the occurrence of a magnetically induced tachyonic instability of the rho meson in the two-flavour Sakai-Sugimoto model, uplifting two remaining approximations in the previous paper. That is, firstly, the magnetically induced splitting of the branes is now taken into account, evaluating without approximations the symmetrized trace which enters in the non-Abelian Dirac-Born-Infeld (DBI) action. This leads to an extra mass generating effect for the charged heavy-light rho meson through a holographic Higgs mechanism. Secondly, we compare the results in the approximation to second order in the field strength to the results using the full DBI-action. Both improvements cause an increase of the critical magnetic field for the onset of rho meson condensation. In addition, the stability in the scalar sector in the presence of the magnetic field is discussed

  2. Conformal Gauge-Yukawa Theories away From Four Dimensions

    DEFF Research Database (Denmark)

    Codello, Alessandro; Langaeble, Kasper; Litim, Daniel

    2016-01-01

    We present the phase diagram and associated fixed points for a wide class of Gauge-Yukawa theories in $d=4+\\epsilon$ dimensions. The theories we investigate involve non-abelian gauge fields, fermions and scalars in the Veneziano-Witten limit. The analysis is performed in steps, we start with QCD...

  3. Protected gates for topological quantum field theories

    Science.gov (United States)

    Beverland, Michael E.; Buerschaper, Oliver; Koenig, Robert; Pastawski, Fernando; Preskill, John; Sijher, Sumit

    2016-02-01

    We study restrictions on locality-preserving unitary logical gates for topological quantum codes in two spatial dimensions. A locality-preserving operation is one which maps local operators to local operators — for example, a constant-depth quantum circuit of geometrically local gates, or evolution for a constant time governed by a geometrically local bounded-strength Hamiltonian. Locality-preserving logical gates of topological codes are intrinsically fault tolerant because spatially localized errors remain localized, and hence sufficiently dilute errors remain correctable. By invoking general properties of two-dimensional topological field theories, we find that the locality-preserving logical gates are severely limited for codes which admit non-abelian anyons, in particular, there are no locality-preserving logical gates on the torus or the sphere with M punctures if the braiding of anyons is computationally universal. Furthermore, for Ising anyons on the M-punctured sphere, locality-preserving gates must be elements of the logical Pauli group. We derive these results by relating logical gates of a topological code to automorphisms of the Verlinde algebra of the corresponding anyon model, and by requiring the logical gates to be compatible with basis changes in the logical Hilbert space arising from local F-moves and the mapping class group.

  4. Protected gates for topological quantum field theories

    Energy Technology Data Exchange (ETDEWEB)

    Beverland, Michael E.; Pastawski, Fernando; Preskill, John [Institute for Quantum Information and Matter, California Institute of Technology, Pasadena, California 91125 (United States); Buerschaper, Oliver [Dahlem Center for Complex Quantum Systems, Freie Universität Berlin, 14195 Berlin (Germany); Koenig, Robert [Institute for Advanced Study and Zentrum Mathematik, Technische Universität München, 85748 Garching (Germany); Sijher, Sumit [Institute for Quantum Computing and Department of Applied Mathematics, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada)

    2016-02-15

    We study restrictions on locality-preserving unitary logical gates for topological quantum codes in two spatial dimensions. A locality-preserving operation is one which maps local operators to local operators — for example, a constant-depth quantum circuit of geometrically local gates, or evolution for a constant time governed by a geometrically local bounded-strength Hamiltonian. Locality-preserving logical gates of topological codes are intrinsically fault tolerant because spatially localized errors remain localized, and hence sufficiently dilute errors remain correctable. By invoking general properties of two-dimensional topological field theories, we find that the locality-preserving logical gates are severely limited for codes which admit non-abelian anyons, in particular, there are no locality-preserving logical gates on the torus or the sphere with M punctures if the braiding of anyons is computationally universal. Furthermore, for Ising anyons on the M-punctured sphere, locality-preserving gates must be elements of the logical Pauli group. We derive these results by relating logical gates of a topological code to automorphisms of the Verlinde algebra of the corresponding anyon model, and by requiring the logical gates to be compatible with basis changes in the logical Hilbert space arising from local F-moves and the mapping class group.

  5. Non-Abelian dark forces and the relic densities of dark glueballs

    Science.gov (United States)

    Forestell, Lindsay; Morrissey, David E.; Sigurdson, Kris

    2017-01-01

    Our understanding of the Universe is known to be incomplete, and new gauge forces beyond those of the Standard Model might be crucial to describing its observed properties. A minimal and well-motivated possibility is a pure Yang-Mills non-Abelian dark gauge force with no direct connection to the Standard Model. We determine here the relic abundances of the glueball bound states that arise in such theories and investigate their cosmological effects. Glueballs are first formed in a confining phase transition, and their relic densities are set by a network of annihilation and transfer reactions. The lightest glueball has no lighter states to annihilate into, and its yield is set mainly by 3 →2 number-changing processes which persistently release energy into the glueball gas during freeze-out. The abundances of the heavier glueballs are dominated by 2 →2 transfer reactions and tend to be much smaller than the lightest state. We also investigate potential connectors between the dark force and the Standard Model that allow some or all of the dark glueballs to decay. If the connection is weak, the lightest glueball can be very long-lived or stable and is a viable dark matter candidate. For stronger connections, the lightest glueball will decay quickly, but other heavier glueball states can remain stable and contribute to the dark matter density.

  6. Dyons, Superstrings, and Wormholes: Exact Solutions of the Non-Abelian Dirac-Born-Infeld Action

    Directory of Open Access Journals (Sweden)

    Edward A. Olszewski

    2015-01-01

    Full Text Available We construct dyon solutions on coincident D4-branes, obtained by applying T-duality transformations to type I SO(32 superstring theory in 10 dimensions. These solutions, which are exact, are obtained from an action comprising the non-Abelian Dirac-Born-Infeld action and a Wess-Zumino-like action. When one spatial dimension of the D4-branes is taken to be vanishingly small, the dyons are analogous to the ’t Hooft/Polyakov monopole residing in a 3+1-dimensional spacetime, where the component of the Yang-Mills potential transforming as a Lorentz scalar is reinterpreted as a Higgs boson transforming in the adjoint representation of the gauge group. Applying a T-duality transformation to the vanishingly small spatial dimension, we obtain a collection of D3-branes, not all of which are coincident. Two of the D3-branes, distinct from the others, acquire intrinsic, finite curvature and are connected by a wormhole. The dyons possess electric and magnetic charges whose values on each D3-brane are the negative of one another. The gravitational effects, which arise after the T-duality transformation, occur despite the fact that the action of the system does not explicitly include the gravitational interaction. These solutions provide a simple example of the subtle relationship between the Yang-Mills and gravitational interactions, that is, gauge/gravity duality.

  7. Fermion number non-conservation and cold neutral fermionic matter in (V-A) gauge theories

    International Nuclear Information System (INIS)

    Matveev, V.A.; Rubakov, V.A.; Tavkhelidze, A.N.; Tokarev, V.F.

    1987-01-01

    It is shown that in four-dimensional abelian (V-A) theories, the ground state of cold neutral fermionic matter is an anomalous state containing domains of abnormal phase surrounded by the normal vacuum. Inside these domains, there exists a gauge field condensate which makes real fermions disappear both inside and outside the domains. In non-abelian theories, the abnormal matter is unstable in its turn, and the system rolls back down into the normal state with a small number of fermions above the topologically non-trivial vacuum. Thus, in several non-abelian gauge theories, the fermion number density of cold neutral matter cannot exceed some critical value. (orig.)

  8. Research program in elementary particle theory

    International Nuclear Information System (INIS)

    Balachandran, A.P.; Rosenzweig, C.; Schechter, J.; Wali, K.C.

    1992-01-01

    In this paper we give a brief account of the work of the group during the past year. The topics covered here include (1) Effective Lagrangians and Solitons; (2) Chern-Simons and Conformal Field Theories; (3) Spin and Statistics; (4) The Standard Model and Beyond; (5) Non-Abelian Monopoles; (6) The Inflationary Universe; (7) The Hubbard Model, and (8) Miscellaneous

  9. Non-abelian anyons and topological quantum information processing in 1D wire networks

    Science.gov (United States)

    Alicea, Jason

    2012-02-01

    Topological quantum computation provides an elegant solution to decoherence, circumventing this infamous problem at the hardware level. The most basic requirement in this approach is the ability to stabilize and manipulate particles exhibiting non-Abelian exchange statistics -- Majorana fermions being the simplest example. Curiously, Majorana fermions have been predicted to arise both in 2D systems, where non-Abelian statistics is well established, and in 1D, where exchange statistics of any type is ill-defined. An important question then arises: do Majorana fermions in 1D hold the same technological promise as their 2D counterparts? In this talk I will answer this question in the affirmative, describing how one can indeed manipulate and harness the non-Abelian statistics of Majoranas in a remarkably simple fashion using networks formed by quantum wires or topological insulator edges.

  10. Generalized Ward identities and Yang-Mills fields

    NARCIS (Netherlands)

    Veltman, M.J.G.

    1970-01-01

    Ward identities for non-Abelian gauges are derived within the framework of field theory. Subsequently these identities are used to analyse diagrams of the massive Yang-Mills theory to arbitrary order. The detailed results for two-closed loops are given.

  11. Non-Abelian monopole in the parameter space of point-like interactions

    International Nuclear Information System (INIS)

    Ohya, Satoshi

    2014-01-01

    We study non-Abelian geometric phase in N=2 supersymmetric quantum mechanics for a free particle on a circle with two point-like interactions at antipodal points. We show that non-Abelian Berry’s connection is that of SU(2) magnetic monopole discovered by Moody, Shapere and Wilczek in the context of adiabatic decoupling limit of diatomic molecule. - Highlights: • Supersymmetric quantum mechanics is an ideal playground for studying geometric phase. • We determine the parameter space of supersymmetric point-like interactions. • Berry’s connection is given by a Wu–Yang-like magnetic monopole in SU(2) Yang–Mills

  12. Condensation and critical exponents of an ideal non-Abelian gas

    Science.gov (United States)

    Talaei, Zahra; Mirza, Behrouz; Mohammadzadeh, Hosein

    2017-11-01

    We investigate an ideal gas obeying non-Abelian statistics and derive the expressions for some thermodynamic quantities. It is found that thermodynamic quantities are finite at the condensation point where their derivatives diverge and, near this point, they behave as \\vert T-Tc\\vert^{-ρ} in which Tc denotes the condensation temperature and ρ is a critical exponent. The critical exponents related to the heat capacity and compressibility are obtained by fitting numerical results and others are obtained using the scaling law hypothesis for a three-dimensional non-Abelian ideal gas. This set of critical exponents introduces a new universality class.

  13. String-nets, single and double-stranded quantum loop gases for non-Abelian anyons

    OpenAIRE

    Velenich, Andrea; Chamon, Claudio; Wen, Xiao-Gang

    2009-01-01

    String-net condensation can give rise to non-Abelian anyons whereas loop condensation usually gives rise to Abelian anyons. It has been proposed that generalized quantum loop gases with non-orthogonal inner products can produce non-Abelian anyons. We detail an exact mapping between the string-net and the generalized loop models and explain how the non-orthogonal products arise. We also introduce a loop model of double-stranded nets where quantum loops with an orthogonal inner product and loca...

  14. Some recent progress on magnetic effects for non-Abelian vortices in color-flavor-locked quark matter

    Directory of Open Access Journals (Sweden)

    ZHANG Yi

    2015-10-01

    Full Text Available It is recently known that strong magnetic fields may lead to highly nontrivial effects on strongly interacting matter,including the color-flavor-locked phase of dense quark matter.Dense quark matter provides various kind of topological solitons such as vortices,domain walls,monopoles,kinks,boojums etc.,it is hence natural to expect that the magnetic field can also affect these topological solitons.In this mini-review,we update our recent progress on the studies of magnetic field effects in the color-flavor-locked quark matter.The particular emphasis is given on the non-Abelian vortices since they are the most fundamental string-like topological excitations under certain circumstance.Their relevant properties (e.g.,the profile function and the tension energy and the magnetic-field dependence are investigated with the Ginzburg-Landau framework.

  15. Geometric symmetries and topological terms in F-theory and field theory

    International Nuclear Information System (INIS)

    Kapfer, Andreas

    2016-01-01

    In this thesis we investigate topological aspects and arithmetic structures in quantum field theory and string theory. Particular focus is put on consistent truncations of supergravity and compactifications of F-theory. The first part treats settings of supersymmetry breaking in five dimensions. We focus on an N=4 to N=2 breaking in gauged supergravity. For certain classes of embedding tensors we can analyze the theory around the vacuum to a great extent. Importantly, one-loop corrections to Chern-Simons terms are generically induced which are independent of the supersymmetry-breaking scale. We investigate concrete examples of consistent truncations of supergravity and M-theory which show this N=4 to N=2 breaking pattern in five dimensions. In particular, we analyze necessary conditions for these consistent truncations to be used as effective theories for phenomenology by demanding consistency of the scale-independent corrections to Chern-Simons couplings. The second part is devoted to the study of anomalies and large gauge transformations in circle-reduced gauge theories and F-theory. We consider four- and six-dimensional matter-coupled gauge theories on the circle and classify all large gauge transformations that preserve the boundary conditions of the matter fields. Enforcing that they act consistently on one-loop Chern-Simons couplings in three and five dimensions explicitly yields all higher-dimensional gauge anomaly cancelation conditions. In the context of F-theory compactifications we identify the classified large gauge transformations along the circle with arithmetic structures on elliptically fibered Calabi-Yau manifolds via the dual M-theory setting. Integer Abelian large gauge transformations correspond to free basis shifts in the Mordell-Weil lattice of rational sections while special fractional non-Abelian large gauge transformations are matched to torsional shifts in the Mordell-Weil group. For integer non-Abelian large gauge transformations we

  16. Geometric symmetries and topological terms in F-theory and field theory

    Energy Technology Data Exchange (ETDEWEB)

    Kapfer, Andreas

    2016-08-25

    In this thesis we investigate topological aspects and arithmetic structures in quantum field theory and string theory. Particular focus is put on consistent truncations of supergravity and compactifications of F-theory. The first part treats settings of supersymmetry breaking in five dimensions. We focus on an N=4 to N=2 breaking in gauged supergravity. For certain classes of embedding tensors we can analyze the theory around the vacuum to a great extent. Importantly, one-loop corrections to Chern-Simons terms are generically induced which are independent of the supersymmetry-breaking scale. We investigate concrete examples of consistent truncations of supergravity and M-theory which show this N=4 to N=2 breaking pattern in five dimensions. In particular, we analyze necessary conditions for these consistent truncations to be used as effective theories for phenomenology by demanding consistency of the scale-independent corrections to Chern-Simons couplings. The second part is devoted to the study of anomalies and large gauge transformations in circle-reduced gauge theories and F-theory. We consider four- and six-dimensional matter-coupled gauge theories on the circle and classify all large gauge transformations that preserve the boundary conditions of the matter fields. Enforcing that they act consistently on one-loop Chern-Simons couplings in three and five dimensions explicitly yields all higher-dimensional gauge anomaly cancelation conditions. In the context of F-theory compactifications we identify the classified large gauge transformations along the circle with arithmetic structures on elliptically fibered Calabi-Yau manifolds via the dual M-theory setting. Integer Abelian large gauge transformations correspond to free basis shifts in the Mordell-Weil lattice of rational sections while special fractional non-Abelian large gauge transformations are matched to torsional shifts in the Mordell-Weil group. For integer non-Abelian large gauge transformations we

  17. MONOPOLES AND DYONS IN THE PURE EINSTEIN YANG MILLS THEORY

    International Nuclear Information System (INIS)

    HOSOTANI, Y.; BJORAKER, J.

    1999-01-01

    In the pure Einstein-Yang-Mills theory in four dimensions there exist monopole and dyon solutions. The spectrum of the solutions is discrete in asymptotically flat or de Sitter space, whereas it is continuous in asymptotically anti-de Sitter space. The solutions are regular everywhere and specified with their mass, and non-Abelian electric and magnetic charges. In asymptotically anti-de Sitter space a class of monopole solutions have no node in non-Abelian magnetic fields, and are stable against spherically symmetric perturbations

  18. Minding one's P's and Q's: From the one loop effective action in quantum field theory to classical transport theory

    International Nuclear Information System (INIS)

    Jalilian-Marian, Jamal; Jeon, Sangyong; Venugopalan, Raju; Wirstam, Jens

    2000-01-01

    The one loop effective action in quantum field theory can be expressed as a quantum mechanical path integral over world lines, with internal symmetries represented by Grassmanian variables. In this paper, we develop a real time, many body, world line formalism for the one loop effective action. In particular, we study hot QCD and obtain the classical transport equations which, as Litim and Manuel have shown, reduce in the appropriate limit to the non-Abelian Boltzmann-Langevin equation first obtained by Boedeker. In the Vlasov limit, the classical kinetic equations are those that correspond to the hard thermal loop effective action. We also discuss the imaginary time world line formalism for a hot φ 4 theory, and elucidate its relation to classical transport theory. (c) 2000 The American Physical Society

  19. Irreversibility and higher-spin conformal field theory

    CERN Document Server

    Anselmi, D

    2000-01-01

    I discuss the idea that quantum irreversibility is a general principle of nature and a related "conformal hypothesis", stating that all fundamental quantum field theories should be renormalization-group (RG) interpolations between ultraviolet and infrared conformal fixed points. In particular, the Newton constant should be viewed as a low-energy effect of the RG scale. This approach leads naturally to consider higher-spin conformal field theories, which are here classified, as candidate high-energy theories. Bosonic conformal tensors have a positive-definite action, equal to the square of a field strength, and a higher-derivative gauge invariance. The central charges c and a are well defined and positive. I calculate their values and study the operator-product structure. Fermionic theories have no gauge invariance and can be coupled to Abelian and non-Abelian gauge fields in a renormalizable way. At the quantum level, they contribute to the one-loop beta function with the same sign as ordinary matter, admit a...

  20. Fractionalizing Majorana Fermions: Non-Abelian Statistics on the Edges of Abelian Quantum Hall States

    Science.gov (United States)

    Lindner, Netanel H.; Berg, Erez; Refael, Gil; Stern, Ady

    2012-10-01

    We study the non-Abelian statistics characterizing systems where counterpropagating gapless modes on the edges of fractional quantum Hall states are gapped by proximity coupling to superconductors and ferromagnets. The most transparent example is that of a fractional quantum spin Hall state, in which electrons of one spin direction occupy a fractional quantum Hall state of ν=1/m, while electrons of the opposite spin occupy a similar state with ν=-1/m. However, we also propose other examples of such systems, which are easier to realize experimentally. We find that each interface between a region on the edge coupled to a superconductor and a region coupled to a ferromagnet corresponds to a non-Abelian anyon of quantum dimension 2m. We calculate the unitary transformations that are associated with the braiding of these anyons, and we show that they are able to realize a richer set of non-Abelian representations of the braid group than the set realized by non-Abelian anyons based on Majorana fermions. We carry out this calculation both explicitly and by applying general considerations. Finally, we show that topological manipulations with these anyons cannot realize universal quantum computation.

  1. Fractionalizing Majorana Fermions: Non-Abelian Statistics on the Edges of Abelian Quantum Hall States

    Directory of Open Access Journals (Sweden)

    Netanel H. Lindner

    2012-10-01

    Full Text Available We study the non-Abelian statistics characterizing systems where counterpropagating gapless modes on the edges of fractional quantum Hall states are gapped by proximity coupling to superconductors and ferromagnets. The most transparent example is that of a fractional quantum spin Hall state, in which electrons of one spin direction occupy a fractional quantum Hall state of ν=1/m, while electrons of the opposite spin occupy a similar state with ν=-1/m. However, we also propose other examples of such systems, which are easier to realize experimentally. We find that each interface between a region on the edge coupled to a superconductor and a region coupled to a ferromagnet corresponds to a non-Abelian anyon of quantum dimension sqrt[2m]. We calculate the unitary transformations that are associated with the braiding of these anyons, and we show that they are able to realize a richer set of non-Abelian representations of the braid group than the set realized by non-Abelian anyons based on Majorana fermions. We carry out this calculation both explicitly and by applying general considerations. Finally, we show that topological manipulations with these anyons cannot realize universal quantum computation.

  2. Constraints on four dimensional effective field theories from string and F-theory

    International Nuclear Information System (INIS)

    Baume, Florent

    2017-01-01

    This thesis is a study of string theory compactifications to four dimensions and the constraints the Effective Field theories must exhibit, exploring both the closed and open sectors. In the former case, we focus on axion monodromy scenarios and the impact the backreaction of the energy density induced by the vev of an axion has on its field excursions. For all the cases studied, we find that the backreaction is small up to a critical value, and the proper field distance is flux independent and at most logarithmic in the axion vev. We then move to the open sector, where we use the framework of F-theory. We first explore the relation between the spectra arising from F-theory GUTs and those coming from a decomposition of the adjoint of E 8 to SU(5) x U(1) n . We find that extending the latter spectrum with new SU(5)-singlet fields, and classifying all possible ways of breaking the Abelian factors, all the spectra coming from smooth elliptic fibration constructed in the literature fit in our classification. We then explore generic properties of the spectra arising when breaking SU(5) to the Standard Model gauge group while retaining some anomaly properties. We finish by a study of F-theory compactications on a singular elliptic fibration via Matrix Factorisation, and find the charged spectrum of two non-Abelian examples.

  3. Holography for field theory solitons

    Science.gov (United States)

    Domokos, Sophia K.; Royston, Andrew B.

    2017-07-01

    We extend a well-known D-brane construction of the AdS/dCFT correspondence to non-abelian defects. We focus on the bulk side of the correspondence and show that there exists a regime of parameters in which the low-energy description consists of two approximately decoupled sectors. The two sectors are gravity in the ambient spacetime, and a six-dimensional supersymmetric Yang-Mills theory. The Yang-Mills theory is defined on a rigid AdS4 × S 2 background and admits sixteen supersymmetries. We also consider a one-parameter deformation that gives rise to a family of Yang-Mills theories on asymptotically AdS4 × S 2 spacetimes, which are invariant under eight supersymmetries. With future holographic applications in mind, we analyze the vacuum structure and perturbative spectrum of the Yang-Mills theory on AdS4 × S 2, as well as systems of BPS equations for finite-energy solitons. Finally, we demonstrate that the classical Yang-Mills theory has a consistent truncation on the two-sphere, resulting in maximally supersymmetric Yang-Mills on AdS4.

  4. Non-Abelian S-term dark energy and inflation

    Science.gov (United States)

    Rodríguez, Yeinzon; Navarro, Andrés A.

    2018-03-01

    We study the role that a cosmic triad in the generalized SU(2) Proca theory, specifically in one of the pieces of the Lagrangian that involves the symmetric version Sμν of the gauge field strength tensor Fμν, has on dark energy and primordial inflation. Regarding dark energy, the triad behaves asymptotically as a couple of radiation perfect fluids whose energy densities are negative for the S term but positive for the Yang-Mills term. This leads to an interesting dynamical fine-tuning mechanism that gives rise to a combined equation of state parameter ω ≃ - 1 and, therefore, to an eternal period of accelerated isotropic expansion for an ample spectrum of initial conditions. Regarding primordial inflation, one of the critical points of the associated dynamical system can describe a prolonged period of isotropic slow-roll inflation sustained by the S term. This period ends up when the Yang-Mills term dominates the energy density leading to the radiation dominated epoch. Unfortunately, in contrast to the dark energy case, the primordial inflation scenario is strongly sensitive to the coupling constants and initial conditions. The whole model, including the other pieces of the Lagrangian that involve Sμν, might evade the recent strong constraints coming from the gravitational wave signal GW170817 and its electromagnetic counterpart GRB 170817A.

  5. String theory duals of Lifshitz–Chern–Simons gauge theories

    International Nuclear Information System (INIS)

    Balasubramanian, Koushik; McGreevy, John

    2012-01-01

    We propose candidate gravity duals for a class of non-Abelian z = 2 Lifshitz Chern–Simons (LCS) gauge theories studied by Mulligan, Kachru and Nayak. These are nonrelativistic gauge theories in 2+1 dimensions in which parity and time-reversal symmetries are explicitly broken by the presence of a Chern–Simons term. We show that these field theories can be realized as deformations of DLCQ N=4 super Yang–Mills theory. Using the holographic dictionary, we identify the bulk fields of type IIB supergravity that are dual to these deformations. The geometries describing the groundstates of the non-Abelian LCS gauge theories realized here exhibit a mass gap. (paper)

  6. String theory or field theory?

    International Nuclear Information System (INIS)

    Marshakov, A.V.

    2002-01-01

    The status of string theory is reviewed, and major recent developments - especially those in going beyond perturbation theory in the string theory and quantum field theory frameworks - are analyzed. This analysis helps better understand the role and place of experimental phenomena, it is emphasized that there are some insurmountable problems inherent in it - notably the impossibility to formulate the quantum theory of gravity on its basis - which prevent it from being a fundamental physical theory of the world of microscopic distances. It is this task, the creation of such a theory, which string theory, currently far from completion, is expected to solve. In spite of its somewhat vague current form, string theory has already led to a number of serious results and greatly contributed to progress in the understanding of quantum field theory. It is these developments, which are our concern in this review [ru

  7. An old-timer looks at modern field theory

    International Nuclear Information System (INIS)

    Weisskopf, V.F.

    1977-01-01

    Four examples of intuitive reasoning in field theory are presented. The first three are concerned with problems of quantum electro-dynamics, namely, the Lamb shift, the radiative correction to the magnetic moment of the electron (the deviation of the electronic g factor from 2), and the polarization of the vacuum by an external charge. The polarization of the vacuum is a simple example of a typical fact resulting from quantum electro-dynamics: the effective charge e' for processes in which momentum transfers q >> m (electron mass) occur, increases with larger q as e' approximately log (q/m). The fourth example deals with an intuitive approach to the problem of 'asymptotic freedom', a term used for the fact that in certain field theories the effective charge e' decreases with larger g as e' approximately (log q/m)sup(-n) where n in the simplest case is 1/2. In these field theories, usually referred to as 'non-Abelian', not only the particles but also the fields are carriers of charge. (U.K.)

  8. Role(s) of anti-symmetrical background field in string theory; Role(s) du champ de fond antisymetrique en theorie des cordes

    Energy Technology Data Exchange (ETDEWEB)

    Fidanza, St

    2003-11-15

    In the first chapter (titled: non-commutative D-branes), we show that the B anti-symmetrical background fields can be embedded in the non-commutativity of branes and can distort gauge theories that branes convey. We know how to describe this transformation in the Abelian case thanks to the Kontsevic quantification formula. Moreover this formula combined to the Seiberg-Witter transformation allows one to compute more rapidly the explicit terms. For the non-Abelian case the situation is less clear. In the chapter 2 (titled: non-Abelian M5-branes), we have tackled the issue of the fields of a packet of N M5-branes. The direct approach based on a 6 dimensional super-symmetric multiplets has led to a stunning dead end, we have not been able to reproduce the expected anomaly in N{sup 3}. We have presented in a unified manner different gauge theories. We have shown that we can get a number of freedom degrees in the magnitude order of N{sup 3} from computations based on geometrical configurations of M2 membranes. In the chapter 3 (titled: systematizing mirror symmetry) we have shown that if the presence of a non-trivial Neveu-Schwarz flux constrains the compactification manifold geometry to shift from the Calabi-Yau case, we can yet specify a mirror symmetry that mixes geometry and background fields. (A.C.)

  9. gl( N, N) current algebras and topological field theories

    Science.gov (United States)

    Isidro, J. M.; Ramallo, A. V.

    1994-02-01

    The conformal field theory for the gl( N, N) affine Lie superalgebra in two space-time dimensions is studied. The energy-momentum tensor of the model, with vanishing Virasoro anomaly, is constructed. This theory has a topological symmetry generated by operators of dimensions 1, 2 and 3, which are represented as normal-ordered products of gl( N, N) currents. The topological algebra they satisfy is linear and differs from the one obtained by twisting the N = 2 superconformal models. It closes with a set of gl( N) bosonic and fermionic currents. The Wess-Zumino-Witten model for the supergroup GL( N, N) provides an explicit realization of this symmetry and can be used to obtain a free-field representation of the different generators. In this free-field representation, the theory decomposes into two uncoupled components with sl( N) and U(1) symmetries. The non-abelian component is responsible for the extended character of the topological algebra, and it is shown to be equivalent to an SL( N)/SL( N) coset model. In the light of these results, the G/G coset models are interpreted as topological sigma models for the group manifold of G.

  10. gl(N, N) current algebras and topological field theories

    International Nuclear Information System (INIS)

    Isidro, J.M.; Ramallo, A.V.

    1994-01-01

    The conformal field theory for the gl(N, N) affine Lie superalgebra in two space-time dimensions is studied. The energy-momentum tensor of the model, with vanishing Virasoro anomaly, is constructed. This theory has a topological symmetry generated by operators of dimensions 1, 2 and 3, which are represented as normal-ordered products of gl(N, N) currents. The topological algebra they satisfy is linear and differs from the one obtained by twisting the N = 2 superconformal models. It closes with a set of gl(N) bosonic and fermionic currents. The Wess-Zumino-Witten model for the supergroup GL(N, N) provides an explicit realization of this symmetry and can be used to obtain a free-field representation of the different generators. In this free-field representation, the theory decomposes into two uncoupled components with sl(N) and U(1) symmetries. The non-abelian component is responsible for the extended character of the topological algebra, and it is shown to be equivalent to an SL(N)/SL(N) coset model. In the light of these results, the G/G coset models are interpreted as topological sigma models for the group manifold of G. (orig.)

  11. String theory or field theory?

    International Nuclear Information System (INIS)

    Marshakov, Andrei V

    2002-01-01

    The status of string theory is reviewed, and major recent developments - especially those in going beyond perturbation theory in the string theory and quantum field theory frameworks - are analyzed. This analysis helps better understand the role and place of string theory in the modern picture of the physical world. Even though quantum field theory describes a wide range of experimental phenomena, it is emphasized that there are some insurmountable problems inherent in it - notably the impossibility to formulate the quantum theory of gravity on its basis - which prevent it from being a fundamental physical theory of the world of microscopic distances. It is this task, the creation of such a theory, which string theory, currently far from completion, is expected to solve. In spite of its somewhat vague current form, string theory has already led to a number of serious results and greatly contributed to progress in the understanding of quantum field theory. It is these developments which are our concern in this review. (reviews of topical problems)

  12. Non-abelian symmetries in tensor networks: A quantum symmetry space approach

    International Nuclear Information System (INIS)

    Weichselbaum, Andreas

    2012-01-01

    A general framework for non-abelian symmetries is presented for matrix-product and tensor-network states in the presence of well-defined orthonormal local as well as effective basis sets. The two crucial ingredients, the Clebsch–Gordan algebra for multiplet spaces as well as the Wigner–Eckart theorem for operators, are accounted for in a natural, well-organized, and computationally straightforward way. The unifying tensor-representation for quantum symmetry spaces, dubbed QSpace, is particularly suitable to deal with standard renormalization group algorithms such as the numerical renormalization group (NRG), the density matrix renormalization group (DMRG), or also more general tensor networks such as the multi-scale entanglement renormalization ansatz (MERA). In this paper, the focus is on the application of the non-abelian framework within the NRG. A detailed analysis is presented for a fully screened spin- 3/2 three-channel Anderson impurity model in the presence of conservation of total spin, particle–hole symmetry, and SU(3) channel symmetry. The same system is analyzed using several alternative symmetry scenarios based on combinations of U(1) charge , SU(2) spin , SU(2) charge , SU(3) channel , as well as the enveloping symplectic Sp(6) symmetry. These are compared in detail, including their respective dramatic gain in numerical efficiency. In the Appendix, finally, an extensive introduction to non-abelian symmetries is given for practical applications, together with simple self-contained numerical procedures to obtain Clebsch–Gordan coefficients and irreducible operators sets. The resulting QSpace tensors can deal with any set of abelian symmetries together with arbitrary non-abelian symmetries with compact, i.e. finite-dimensional, semi-simple Lie algebras. - Highlights: ► We introduce a transparent framework for non-abelian symmetries in tensor networks. ► The framework was successfully applied within the numerical renormalization group.

  13. Non-abelian bosonization in higher genus Riemann surfaces

    International Nuclear Information System (INIS)

    Koh, I.G.; Yu, M.

    1987-08-01

    We propose a generalization of the character formulas of the SU(2) Kac-Moody algebra to higher genus Riemann surfaces. With this construction, we show that the modular invariant partition function of the SO(4) κ = 1 Wess-Zumino model is equivalent, in arbitrary genus Riemann surfaces, to that of free fermion theory. (orig.)

  14. Non-abelian bosonization in higher genus Riemann surfaces

    International Nuclear Information System (INIS)

    Koh, I.G.; Yu, M.

    1988-01-01

    We propose a generalization of the character formulas of the SU(2) Kac-Moody algebra to higher genus Riemann surfaces. With this construction, we show that the modular invariant partition funciton of the SO(4) k = 1 Wess-Zumino model is equivalent, in arbitrary genus Riemann surfaces, to that of free fermion theory. (orig.)

  15. The gauge invariance of the non-Abelian Chern-Simons action for D-branes revisited

    International Nuclear Information System (INIS)

    Adam, J.; Gheerardyn, J.; Janssen, B.; Lozano, Y.

    2004-01-01

    We present an elegant method to prove the invariance of the Chern-Simons part of the non-Abelian action for N coinciding D-branes under the R-R and NS-NS gauge transformations, by carefully defining what is meant by a background gauge transformation in the non-Abelian world volume action. We study as well the invariance under massive gauge transformations of the massive Type IIA supergravity and show that no massive dielectric couplings are necessary to achieve this invariance. We show that this result is consistent with (massive) T-duality from the non-Abelian action for N D9-branes

  16. Z n clock models and chains of so(n)2 non-Abelian anyons: symmetries, integrable points and low energy properties

    Science.gov (United States)

    Finch, Peter E.; Flohr, Michael; Frahm, Holger

    2018-02-01

    We study two families of quantum models which have been used previously to investigate the effect of topological symmetries in one-dimensional correlated matter. Various striking similarities are observed between certain {Z}n quantum clock models, spin chains generalizing the Ising model, and chains of non-Abelian anyons constructed from the so(n)2 fusion category for odd n, both subject to periodic boundary conditions. In spite of the differences between these two types of quantum chains, e.g. their Hilbert spaces being spanned by tensor products of local spin states or fusion paths of anyons, the symmetries of the lattice models are shown to be closely related. Furthermore, under a suitable mapping between the parameters describing the interaction between spins and anyons the respective Hamiltonians share part of their energy spectrum (although their degeneracies may differ). This spin-anyon correspondence can be extended by fine-tuning of the coupling constants leading to exactly solvable models. We show that the algebraic structures underlying the integrability of the clock models and the anyon chain are the same. For n  =  3,5,7 we perform an extensive finite size study—both numerical and based on the exact solution—of these models to map out their ground state phase diagram and to identify the effective field theories describing their low energy behaviour. We observe that the continuum limit at the integrable points can be described by rational conformal field theories with extended symmetry algebras which can be related to the discrete ones of the lattice models.

  17. Non-abelian factorisation for next-to-leading-power threshold logarithms

    Energy Technology Data Exchange (ETDEWEB)

    Bonocore, D. [Nikhef, Science Park 105, NL-1098 XG Amsterdam (Netherlands); Institute for Theoretical Particle Physics and Cosmology, RWTH Aachen University, Sommerfeldstr. 16, 52074 Aachen (Germany); Laenen, E. [Nikhef, Science Park 105, NL-1098 XG Amsterdam (Netherlands); ITFA, University of Amsterdam, Science Park 904, Amsterdam (Netherlands); ITF, Utrecht University, Leuvenlaan 4, Utrecht (Netherlands); Kavli Institute for Theoretical Physics, University of California, Santa Barbara, CA 93106-4030 (United States); Magnea, L. [Dipartimento di Fisica, Università di Torino and INFN, Sezione di Torino, Via P. Giuria 1, I-10125 Torino (Italy); Vernazza, L. [Higgs Centre for Theoretical Physics, School of Physics and Astronomy, The University of Edinburgh, Edinburgh EH9 3JZ, Scotland (United Kingdom); White, C.D. [Centre for Research in String Theory, School of Physics and Astronomy, Queen Mary University of London, 327 Mile End Road, London E1 4NS (United Kingdom)

    2016-12-22

    Soft and collinear radiation is responsible for large corrections to many hadronic cross sections, near thresholds for the production of heavy final states. There is much interest in extending our understanding of this radiation to next-to-leading power (NLP) in the threshold expansion. In this paper, we generalise a previously proposed all-order NLP factorisation formula to include non-abelian corrections. We define a non-abelian radiative jet function, organising collinear enhancements at NLP, and compute it for quark jets at one loop. We discuss in detail the issue of double counting between soft and collinear regions. Finally, we verify our prescription by reproducing all NLP logarithms in Drell-Yan production up to NNLO, including those associated with double real emission. Our results constitute an important step in the development of a fully general resummation formalism for NLP threshold effects.

  18. Evidence for non-Abelian dark matter from large scale structure?

    CERN Multimedia

    CERN. Geneva

    2015-01-01

    If dark matter multiplicity arises from a weakly coupled non-Abelian dark gauge group the corresponding "dark gluons" can have interesting signatures in cosmology which I will review: 1. the "dark gluons" contribute to the radiation content of the universe and 2. gluon interactions with the dark matter may explain the >3 sigma discrepancy between precision fits to the CMB from Planck and direct measurements of large scale structure in the universe.

  19. Dark matter model with non-Abelian gauge symmetry

    International Nuclear Information System (INIS)

    Zhang Hao; Li Chongsheng; Cao Qinghong; Li Zhao

    2010-01-01

    We propose a dark-matter model in which the dark sector is gauged under a new SU(2) group. The dark sector consists of SU(2) dark gauge fields, two triplet dark Higgs fields, and two dark fermion doublets (dark-matter candidates in this model). The dark sector interacts with the standard model sector through kinetic and mass mixing operators. The model explains both PAMELA and Fermi LAT data very well and also satisfies constraints from both the dark-matter relic density and standard model precision observables. The phenomenology of the model at the LHC is also explored.

  20. A new formulation of quantum field theory on S4

    International Nuclear Information System (INIS)

    Harris, B.A.; Joshi, G.C.

    1993-01-01

    Recent developments in quantum gravity suggest that wormholes may influence the observed values of the constants of nature. The Euclidean formulation of quantum gravity predicts that wormholes induce a probability distribution in the space of possible fundamentals constants. In particular, the effective action on a large spherical space may lead to the vanishing of the cosmological constant and possibly determine the values of other constants of nature. The ability to perform calculations involving interacting quantum fields, particularly non-Abelian models, on a four-sphere is vital if one is to investigate this possibility. In this paper, a new formulation of field theory on a four-sphere is presented using the angular momentum space representation of SO(5). A review of field theory on a sphere is given and then show how a matrix element prescription in angular momentum space and a new summation technique based on the complex l-plane, overcome previous limitations in calculation techniques. The standard one-loop graphs of QED are given as examples. 13 refs., 3 figs

  1. Motion of small bodies in classical field theory

    International Nuclear Information System (INIS)

    Gralla, Samuel E.

    2010-01-01

    I show how prior work with R. Wald on geodesic motion in general relativity can be generalized to classical field theories of a metric and other tensor fields on four-dimensional spacetime that (1) are second-order and (2) follow from a diffeomorphism-covariant Lagrangian. The approach is to consider a one-parameter-family of solutions to the field equations satisfying certain assumptions designed to reflect the existence of a body whose size, mass, and various charges are simultaneously scaled to zero. (That such solutions exist places a further restriction on the class of theories to which our results apply.) Assumptions are made only on the spacetime region outside of the body, so that the results apply independent of the body's composition (and, e.g., black holes are allowed). The worldline 'left behind' by the shrinking, disappearing body is interpreted as its lowest-order motion. An equation for this worldline follows from the 'Bianchi identity' for the theory, without use of any properties of the field equations beyond their being second-order. The form of the force law for a theory therefore depends only on the ranks of its various tensor fields; the detailed properties of the field equations are relevant only for determining the charges for a particular body (which are the ''monopoles'' of its exterior fields in a suitable limiting sense). I explicitly derive the force law (and mass-evolution law) in the case of scalar and vector fields, and give the recipe in the higher-rank case. Note that the vector force law is quite complicated, simplifying to the Lorentz force law only in the presence of the Maxwell gauge symmetry. Example applications of the results are the motion of 'chameleon' bodies beyond the Newtonian limit, and the motion of bodies in (classical) non-Abelian gauge theory. I also make some comments on the role that scaling plays in the appearance of universality in the motion of bodies.

  2. Improved HDRG decoders for qudit and non-Abelian quantum error correction

    Science.gov (United States)

    Hutter, Adrian; Loss, Daniel; Wootton, James R.

    2015-03-01

    Hard-decision renormalization group (HDRG) decoders are an important class of decoding algorithms for topological quantum error correction. Due to their versatility, they have been used to decode systems with fractal logical operators, color codes, qudit topological codes, and non-Abelian systems. In this work, we develop a method of performing HDRG decoding which combines strengths of existing decoders and further improves upon them. In particular, we increase the minimal number of errors necessary for a logical error in a system of linear size L from \\Theta ({{L}2/3}) to Ω ({{L}1-ε }) for any ε \\gt 0. We apply our algorithm to decoding D({{{Z}}d}) quantum double models and a non-Abelian anyon model with Fibonacci-like fusion rules, and show that it indeed significantly outperforms previous HDRG decoders. Furthermore, we provide the first study of continuous error correction with imperfect syndrome measurements for the D({{{Z}}d}) quantum double models. The parallelized runtime of our algorithm is poly(log L) for the perfect measurement case. In the continuous case with imperfect syndrome measurements, the averaged runtime is O(1) for Abelian systems, while continuous error correction for non-Abelian anyons stays an open problem.

  3. FAST TRACK COMMUNICATION: String-nets, single- and double-stranded quantum loop gases for non-Abelian anyons

    Science.gov (United States)

    Velenich, Andrea; Chamon, Claudio; Wen, Xiao-Gang

    2010-04-01

    String-nets and quantum loop gases are two prominent microscopic lattice models to describe topological phases. String-net condensation can give rise to both Abelian and non-Abelian anyons, whereas loop condensation usually produces Abelian anyons. It has been proposed, however, that generalized quantum loop gases with non-orthogonal inner products could support non-Abelian anyons. We detail an exact mapping between the string-net and these generalized loop models and explain how the non-orthogonal products arise. We also introduce an equivalent loop model of double-stranded nets where quantum loops with an orthogonal inner product and local interactions supports non-Abelian Fibonacci anyons. Finally, we emphasize the origin of the sign problem in systems with non-Abelian excitations and its consequences on the complexity of their ground state wavefunctions.

  4. Field theories with subcanonical fields

    International Nuclear Information System (INIS)

    Bigi, I.I.Y.

    1976-01-01

    The properties of quantum field theories with spinor fields of dimension less than the canonical value of 3/2 are studied. As a starting point for the application of common perturbation theory we look for the linear version of these theories. A gange-interaction is introduced and with the aid of power counting the renormalizability of the theory is shown. It follows that in the case of a spinor-field with negative dimension renormalization can only be attained if the interaction has a further symmetry. By this symmetry the theory is determined in an unequivocal way. The gange-interaction introduced in the theory leads to a spontaneous breakdown of scale invariance whereby masses are produced. At the same time the spinor-field operators can now be separated in two orthogonal sections with opposite norm. It is proposed to use the section with negative (positive) norm to describe hadrons (leptons) respectively. (orig./WL) [de

  5. Characterizing asymptotically anti-de Sitter black holes with abundant stable gauge field hair

    International Nuclear Information System (INIS)

    Shepherd, Ben L; Winstanley, Elizabeth

    2012-01-01

    In the light of the 'no-hair' conjecture, we revisit stable black holes in su(N) Einstein-Yang-Mills theory with a negative cosmological constant Λ. These black holes are endowed with copious amounts of gauge field hair, and we address the question of whether these black holes can be uniquely characterized by their mass and a set of global non-Abelian charges defined far from the black hole. For the su(3) case, we present numerical evidence that stable black hole configurations are fixed by their mass and two non-Abelian charges. For general N, we argue that the mass and N - 1 non-Abelian charges are sufficient to characterize large stable black holes, in keeping with the spirit of the 'no-hair' conjecture, at least in the limit of very large |Λ| and for a subspace containing stable black holes (and possibly some unstable ones as well). (paper)

  6. Topological Nematic States and Non-Abelian Lattice Dislocations

    Directory of Open Access Journals (Sweden)

    Maissam Barkeshli

    2012-08-01

    Full Text Available An exciting new prospect in condensed matter physics is the possibility of realizing fractional quantum Hall states in simple lattice models without a large external magnetic field. A fundamental question is whether qualitatively new states can be realized on the lattice as compared with ordinary fractional quantum Hall states. Here we propose new symmetry-enriched topological states, topological nematic states, which are a dramatic consequence of the interplay between the lattice translational symmetry and topological properties of these fractional Chern insulators. The topological nematic states are realized in a partially filled flat band with a Chern number N, which can be mapped to an N-layer quantum Hall system on a regular lattice. However, in the topological nematic states the lattice dislocations can act as wormholes connecting the different layers and effectively change the topology of the space. Consequently, lattice dislocations become defects with a nontrivial quantum dimension, even when the fractional quantum Hall state being realized is, by itself, Abelian. Our proposal leads to the possibility of realizing the physics of topologically ordered states on high-genus surfaces in the lab even though the sample has only the disk geometry.

  7. Field theory and strings

    International Nuclear Information System (INIS)

    Bonara, L.; Cotta-Ramusino, P.; Rinaldi, M.

    1987-01-01

    It is well-known that type I and heterotic superstring theories have a zero mass spectrum which correspond to the field content of N=1 supergravity theory coupled to supersymmetric Yang-Mills theory in 10-D. The authors study the field theory ''per se'', in the hope that simple consistency requirements will determine the theory completely once one knows the field content inherited from string theory. The simplest consistency requirements are: N=1 supersymmetry; and absence of chiral anomalies. This is what the authors discuss in this paper here leaving undetermined the question of the range of validity of the resulting field theory. As is known, a model of N=1 supergravity (SUGRA) coupled to supersymmetric Yang-Mills (SYM) theory was known in the form given by Chapline and Manton. The coupling of SUGRA to SYM was determined by the definition of the ''field strength'' 3-form H in this paper

  8. The Global Approach to Quantum Field Theory

    International Nuclear Information System (INIS)

    Folacci, Antoine; Jensen, Bruce

    2003-01-01

    Thanks to its impressive success in the second half of the 20th century, both in high-energy physics and in critical phenomena, quantum field theory has enjoyed an abundant literature. We therefore greet yet another book on this subject with caution: what can a monograph on quantum field theory bring now that is new, either conceptually or pedagogically? But when it is written by a physicist such as Bryce DeWitt, who has made his own contribution to the collection of field theory books with The Global Approach to Quantum Field Theory, all suspicion is naturally abandoned. DeWitt has made a formidable contribution to various areas of physics: general relativity, the interpretation of quantum mechanics, and most of all the quantization of non-Abelian gauge theories and quantum gravity. In addition, his pedagogical publications, especially the Les Houches schools of 1963 and 1983, have had a great impact on quantum field theory. We must begin by alerting the potential readers of this book that it cannot be compared to any other book in the field. This uniqueness applies to both the scientific content and the way the ideas are presented. For DeWitt, a central concept of field theory is that of 'space of histories'. For a field varphi i defined on a given spacetime M, the set of all varphi i (x) for all x in all charts of M defines its history. It is the space Phi of all possible histories (dynamically allowed or not) of the fields defined on M which is called the 'pace of histories' by DeWitt. If only bosonic fields are considered, the space of histories is an infinite-dimensional manifold and if fermionic fields are also present, it must be viewed as an infinite-dimensional supermanifold. The fields can then be regarded as coordinates on these structures, and the geometrical notions of differentiation, metric, connections, measure, as well as the geodesics which can be defined on it, are of fundamental importance in the development of the formalism of quantum field

  9. Quantum field theory

    International Nuclear Information System (INIS)

    Ryder, L.H.

    1985-01-01

    This introduction to the ideas and techniques of quantum field theory presents the material as simply as possible and is designed for graduate research students. After a brief survey of particle physics, the quantum theory of scalar and spinor fields and then of gauge fields, is developed. The emphasis throughout is on functional methods, which have played a large part in modern field theory. The book concludes with a bridge survey of ''topological'' objects in field theory and assumes a knowledge of quantum mechanics and special relativity

  10. Anomaly cancellation condition in abelian lattice gauge theories

    International Nuclear Information System (INIS)

    Suzuki, Hiroshi

    1999-11-01

    We analyze the general solution of the Wess-Zumino consistency condition in abelian lattice gauge theories, without taking the classical continuum limit. We find that, if the anomaly density is a local pseudo-scalar field on the lattice, the non-trivial anomaly is always proportional to the anomaly coefficient in the continuum theory. The possible extension of this result to non-abelian theories is briefly discussed. (author)

  11. String field theory

    International Nuclear Information System (INIS)

    Kaku, M.

    1987-01-01

    In this article, the authors summarize the rapid progress in constructing string field theory actions, such as the development of the covariant BRST theory. They also present the newer geometric formulation of string field theory, from which the BRST theory and the older light cone theory can be derived from first principles. This geometric formulation allows us to derive the complete field theory of strings from two geometric principles, in the same way that general relativity and Yang-Mills theory can be derived from two principles based on global and local symmetry. The geometric formalism therefore reduces string field theory to a problem of finding an invariant under a new local gauge group they call the universal string group (USG). Thus, string field theory is the gauge theory of the universal string group in much the same way that Yang-Mills theory is the gauge theory of SU(N). The geometric formulation places superstring theory on the same rigorous group theoretical level as general relativity and gauge theory

  12. Algebraic conformal field theory

    International Nuclear Information System (INIS)

    Fuchs, J.; Nationaal Inst. voor Kernfysica en Hoge-Energiefysica

    1991-11-01

    Many conformal field theory features are special versions of structures which are present in arbitrary 2-dimensional quantum field theories. So it makes sense to describe 2-dimensional conformal field theories in context of algebraic theory of superselection sectors. While most of the results of the algebraic theory are rather abstract, conformal field theories offer the possibility to work out many formulae explicitly. In particular, one can construct the full algebra A-bar of global observables and the endomorphisms of A-bar which represent the superselection sectors. Some explicit results are presented for the level 1 so(N) WZW theories; the algebra A-bar is found to be the enveloping algebra of a Lie algebra L-bar which is an extension of the chiral symmetry algebra of the WZW theory. (author). 21 refs., 6 figs

  13. Gauge/string duality in confining theories

    International Nuclear Information System (INIS)

    Edelstein, J.D.; Portugues, R.

    2006-01-01

    This is the content of a set of lectures given at the ''XIII Jorge Andre Swieca Summer School on Particles and Fields'', Campos do Jordao, Brazil in January 2005. They intend to be a basic introduction to the topic of gauge/gravity duality in confining theories. We start by reviewing some key aspects of the low energy physics of non-Abelian gauge theories. Then, we present the basics of the AdS/CFT correspondence and its extension both to gauge theories in different spacetime dimensions with sixteen supercharges and to more realistic situations with less supersymmetry. We discuss the different options of interest: placing D-branes at singularities and wrapping D-branes in calibrated cycles of special holonomy manifolds. We finally present an outline of a number of non-perturbative phenomena in non-Abelian gauge theories as seen from supergravity. (Abstract Copyright [2006], Wiley Periodicals, Inc.)

  14. Gauge/string duality in confining theories

    Energy Technology Data Exchange (ETDEWEB)

    Edelstein, J.D. [Departamento de Fi sica de Particulas, Universidade de Santiago de Compostela and Instituto Galego de Fisica de Altas Enerxias (IGFAE), 15782 Santiago de Compostela (Spain); Instituto de Fisica de La Plata (IFLP), Universidad Nacional de La Plata, La Plata (Argentina); Centro de Estudios Cientificos (CECS), Casilla 1469, Valdivia (Chile); Portugues, R. [Centro de Estudios Cientificos (CECS), Casilla 1469, Valdivia (Chile)

    2006-07-03

    This is the content of a set of lectures given at the ''XIII Jorge Andre Swieca Summer School on Particles and Fields'', Campos do Jordao, Brazil in January 2005. They intend to be a basic introduction to the topic of gauge/gravity duality in confining theories. We start by reviewing some key aspects of the low energy physics of non-Abelian gauge theories. Then, we present the basics of the AdS/CFT correspondence and its extension both to gauge theories in different spacetime dimensions with sixteen supercharges and to more realistic situations with less supersymmetry. We discuss the different options of interest: placing D-branes at singularities and wrapping D-branes in calibrated cycles of special holonomy manifolds. We finally present an outline of a number of non-perturbative phenomena in non-Abelian gauge theories as seen from supergravity. (Abstract Copyright [2006], Wiley Periodicals, Inc.)

  15. Conformal field theory

    CERN Document Server

    Ketov, Sergei V

    1995-01-01

    Conformal field theory is an elegant and powerful theory in the field of high energy physics and statistics. In fact, it can be said to be one of the greatest achievements in the development of this field. Presented in two dimensions, this book is designed for students who already have a basic knowledge of quantum mechanics, field theory and general relativity. The main idea used throughout the book is that conformal symmetry causes both classical and quantum integrability. Instead of concentrating on the numerous applications of the theory, the author puts forward a discussion of the general

  16. Chern-Simons couplings for dielectric F-strings in matrix string theory

    International Nuclear Information System (INIS)

    Brecher, Dominic; Janssen, Bert; Lozano, Yolanda

    2002-01-01

    We compute the non-abelian couplings in the Chern-Simons action for a set of coinciding fundamental strings in both the type IIA and type IIB Matrix string theories. Starting from Matrix theory in a weakly curved background, we construct the linear couplings of closed string fields to type IIA Matrix strings. Further dualities give a type IIB Matrix string theory and a type IIA theory of Matrix strings with winding. (Abstract Copyright[2002], Wiley Periodicals, Inc.)

  17. Finite discrete field theory

    International Nuclear Information System (INIS)

    Souza, Manoelito M. de

    1997-01-01

    We discuss the physical meaning and the geometric interpretation of implementation in classical field theories. The origin of infinities and other inconsistencies in field theories is traced to fields defined with support on the light cone; a finite and consistent field theory requires a light-cone generator as the field support. Then, we introduce a classical field theory with support on the light cone generators. It results on a description of discrete (point-like) interactions in terms of localized particle-like fields. We find the propagators of these particle-like fields and discuss their physical meaning, properties and consequences. They are conformally invariant, singularity-free, and describing a manifestly covariant (1 + 1)-dimensional dynamics in a (3 = 1) spacetime. Remarkably this conformal symmetry remains even for the propagation of a massive field in four spacetime dimensions. We apply this formalism to Classical electrodynamics and to the General Relativity Theory. The standard formalism with its distributed fields is retrieved in terms of spacetime average of the discrete field. Singularities are the by-products of the averaging process. This new formalism enlighten the meaning and the problem of field theory, and may allow a softer transition to a quantum theory. (author)

  18. Geophysical Field Theory

    International Nuclear Information System (INIS)

    Eloranta, E.

    2003-11-01

    The geophysical field theory includes the basic principles of electromagnetism, continuum mechanics, and potential theory upon which the computational modelling of geophysical phenomena is based on. Vector analysis is the main mathematical tool in the field analyses. Electrostatics, stationary electric current, magnetostatics, and electrodynamics form a central part of electromagnetism in geophysical field theory. Potential theory concerns especially gravity, but also electrostatics and magnetostatics. Solid state mechanics and fluid mechanics are central parts in continuum mechanics. Also the theories of elastic waves and rock mechanics belong to geophysical solid state mechanics. The theories of geohydrology and mass transport form one central field theory in geophysical fluid mechanics. Also heat transfer is included in continuum mechanics. (orig.)

  19. Nonlocal continuum field theories

    CERN Document Server

    2002-01-01

    Nonlocal continuum field theories are concerned with material bodies whose behavior at any interior point depends on the state of all other points in the body -- rather than only on an effective field resulting from these points -- in addition to its own state and the state of some calculable external field. Nonlocal field theory extends classical field theory by describing the responses of points within the medium by functionals rather than functions (the "constitutive relations" of classical field theory). Such considerations are already well known in solid-state physics, where the nonlocal interactions between the atoms are prevalent in determining the properties of the material. The tools developed for crystalline materials, however, do not lend themselves to analyzing amorphous materials, or materials in which imperfections are a major part of the structure. Nonlocal continuum theories, by contrast, can describe these materials faithfully at scales down to the lattice parameter. This book presents a unif...

  20. Constrained Gauge Fields from Spontaneous Lorentz Violation

    CERN Document Server

    Chkareuli, J L; Jejelava, J G; Nielsen, H B

    2008-01-01

    Spontaneous Lorentz violation realized through a nonlinear vector field constraint of the type $A_{\\mu}^{2}=M^{2}$ ($M$ is the proposed scale for Lorentz violation) is shown to generate massless vector Goldstone bosons, gauging the starting global internal symmetries in arbitrary relativistically invariant theories. The gauge invariance appears in essence as a necessary condition for these bosons not to be superfluously restricted in degrees of freedom, apart from the constraint due to which the true vacuum in a theory is chosen by the Lorentz violation. In the Abelian symmetry case the only possible theory proves to be QED with a massless vector Goldstone boson naturally associated with the photon, while the non-Abelian symmetry case results in a conventional Yang-Mills theory. These theories, both Abelian and non-Abelian, look essentially nonlinear and contain particular Lorentz (and $CPT$) violating couplings when expressed in terms of the pure Goldstone vector modes. However, they do not lead to physical ...

  1. Superspace conformal field theory

    International Nuclear Information System (INIS)

    Quella, Thomas

    2013-07-01

    Conformal sigma models and WZW models on coset superspaces provide important examples of logarithmic conformal field theories. They possess many applications to problems in string and condensed matter theory. We review recent results and developments, including the general construction of WZW models on type I supergroups, the classification of conformal sigma models and their embedding into string theory.

  2. Superspace conformal field theory

    Energy Technology Data Exchange (ETDEWEB)

    Quella, Thomas [Koeln Univ. (Germany). Inst. fuer Theoretische Physik; Schomerus, Volker [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2013-07-15

    Conformal sigma models and WZW models on coset superspaces provide important examples of logarithmic conformal field theories. They possess many applications to problems in string and condensed matter theory. We review recent results and developments, including the general construction of WZW models on type I supergroups, the classification of conformal sigma models and their embedding into string theory.

  3. Hyperfunction quantum field theory

    International Nuclear Information System (INIS)

    Nagamachi, S.; Mugibayashi, N.

    1976-01-01

    The quantum field theory in terms of Fourier hyperfunctions is constructed. The test function space for hyperfunctions does not contain C infinitely functios with compact support. In spite of this defect the support concept of H-valued Fourier hyperfunctions allows to formulate the locality axiom for hyperfunction quantum field theory. (orig.) [de

  4. The Global Approach to Quantum Field Theory

    Energy Technology Data Exchange (ETDEWEB)

    Folacci, Antoine; Jensen, Bruce [Faculte des Sciences, Universite de Corse (France); Department of Mathematics, University of Southampton (United Kingdom)

    2003-12-12

    Thanks to its impressive success in the second half of the 20th century, both in high-energy physics and in critical phenomena, quantum field theory has enjoyed an abundant literature. We therefore greet yet another book on this subject with caution: what can a monograph on quantum field theory bring now that is new, either conceptually or pedagogically? But when it is written by a physicist such as Bryce DeWitt, who has made his own contribution to the collection of field theory books with The Global Approach to Quantum Field Theory, all suspicion is naturally abandoned. DeWitt has made a formidable contribution to various areas of physics: general relativity, the interpretation of quantum mechanics, and most of all the quantization of non-Abelian gauge theories and quantum gravity. In addition, his pedagogical publications, especially the Les Houches schools of 1963 and 1983, have had a great impact on quantum field theory. We must begin by alerting the potential readers of this book that it cannot be compared to any other book in the field. This uniqueness applies to both the scientific content and the way the ideas are presented. For DeWitt, a central concept of field theory is that of 'space of histories'. For a field varphi{sup i} defined on a given spacetime M, the set of all varphi{sup i}(x) for all x in all charts of M defines its history. It is the space Phi of all possible histories (dynamically allowed or not) of the fields defined on M which is called the 'pace of histories' by DeWitt. If only bosonic fields are considered, the space of histories is an infinite-dimensional manifold and if fermionic fields are also present, it must be viewed as an infinite-dimensional supermanifold. The fields can then be regarded as coordinates on these structures, and the geometrical notions of differentiation, metric, connections, measure, as well as the geodesics which can be defined on it, are of fundamental importance in the development of the

  5. Engineering field theory

    CERN Document Server

    Baden Fuller, A J

    2014-01-01

    Engineering Field Theory focuses on the applications of field theory in gravitation, electrostatics, magnetism, electric current flow, conductive heat transfer, fluid flow, and seepage.The manuscript first ponders on electric flux, electrical materials, and flux function. Discussions focus on field intensity at the surface of a conductor, force on a charged surface, atomic properties, doublet and uniform field, flux tube and flux line, line charge and line sink, field of a surface charge, field intensity, flux density, permittivity, and Coulomb's law. The text then takes a look at gravitation

  6. Stochastic quantization of field theories on the lattice and supersymmetrical models

    International Nuclear Information System (INIS)

    Aldazabal, Gerardo.

    1984-01-01

    Several aspects of the stochastic quantization method are considered. Specifically, field theories on the lattice and supersymmetrical models are studied. A non-linear sigma model is studied firstly, and it is shown that it is possible to obtain evolution equations written directly for invariant quantities. These ideas are generalized to obtain Langevin equations for the Wilson loops of non-abelian lattice gauge theories U (N) and SU (N). In order to write these equations, some different ways of introducing the constraints which the fields must satisfy are discussed. It is natural to have a strong coupling expansion in these equations. The correspondence with quantum field theory is established, and it is noticed that at all orders in the perturbation theory, Langevin equations reduce to Schwinger-Dyson equations. From another point of view, stochastic quantization is applied to large N matrix models on the lattice. As a result, a simple and systematic way of building reduced models is found. Referring to stochastic quantization in supersymmetric theories, a simple supersymmetric model is studied. It is shown that it is possible to write an evolution equation for the superfield wich leads to quantum field theory results in equilibrium. As the Langevin equation preserves supersymmetry, the property of dimensional reduction known for the quantum model is shown to be valid at all times. (M.E.L.) [es

  7. Quantum field theory

    CERN Document Server

    Mandl, Franz

    2010-01-01

    Following on from the successful first (1984) and revised (1993) editions, this extended and revised text is designed as a short and simple introduction to quantum field theory for final year physics students and for postgraduate students beginning research in theoretical and experimental particle physics. The three main objectives of the book are to: Explain the basic physics and formalism of quantum field theory To make the reader proficient in theory calculations using Feynman diagrams To introduce the reader to gauge theories, which play a central role in elementary particle physic

  8. Closed string field theory

    International Nuclear Information System (INIS)

    Strominger, A.

    1987-01-01

    A gauge invariant cubic action describing bosonic closed string field theory is constructed. The gauge symmetries include local spacetime diffeomorphisms. The conventional closed string spectrum and trilinear couplings are reproduced after spontaneous symmetry breaking. The action S is constructed from the usual ''open string'' field of ghost number minus one half. It is given by the associator of the string field product which is non-vanishing because of associativity anomalies. S does not describe open string propagation because open string states associate and can thereby be shifted away. A field theory of closed and open strings can be obtained by adding to S the cubic open string action. (orig.)

  9. Matrix biorthogonal polynomials on the unit circle and non-Abelian Ablowitz-Ladik hierarchy

    International Nuclear Information System (INIS)

    Cafasso, Mattia

    2009-01-01

    Adler and van Moerbeke (2001 Commun. Pure Appl. Math. 54 153-205) described a reduction of the 2D-Toda hierarchy called the Toeplitz lattice. This hierarchy turns out to be equivalent to the one originally described by Ablowitz and Ladik (1975 J. Math. Phys. 16 598-603) using semidiscrete zero- curvature equations. In this paper, we obtain the original semidiscrete zero-curvature equations starting directly from the Toeplitz lattice and we generalize these computations to the matrix case. This generalization leads us to the semidiscrete zero-curvature equations for the non-Abelian (or multicomponent) version of the Ablowitz-Ladik equations (Gerdzhikov and Ivanov 1982 Theor. Math. Phys. 52 676-85). In this way, we extend the link between biorthogonal polynomials on the unit circle and the Ablowitz-Ladik hierarchy to the matrix case.

  10. Experimental state control by fast non-Abelian holonomic gates with a superconducting qutrit

    Science.gov (United States)

    Danilin, S.; Vepsäläinen, A.; Paraoanu, G. S.

    2018-05-01

    Quantum state manipulation with gates based on geometric phases acquired during cyclic operations promises inherent fault-tolerance and resilience to local fluctuations in the control parameters. Here we create a general non-Abelian and non-adiabatic holonomic gate acting in the (| 0> ,| 2> ) subspace of a three-level (qutrit) transmon device fabricated in a fully coplanar design. Experimentally, this is realized by simultaneously coupling the first two transitions by microwave pulses with amplitudes and phases defined such that the condition of parallel transport is fulfilled. We demonstrate the creation of arbitrary superpositions in this subspace by changing the amplitudes of the pulses and the relative phase between them. We use two-photon pulses acting in the holonomic subspace to reveal the coherence of the state created by the geometric gate pulses and to prepare different superposition states. We also test the action of holonomic NOT and Hadamard gates on superpositions in the (| 0> ,| 2> ) subspace.

  11. Interpolating string field theories

    International Nuclear Information System (INIS)

    Zwiebach, B.

    1992-01-01

    This paper reports that a minimal area problem imposing different length conditions on open and closed curves is shown to define a one-parameter family of covariant open-closed quantum string field theories. These interpolate from a recently proposed factorizable open-closed theory up to an extended version of Witten's open string field theory capable of incorporating on shell closed strings. The string diagrams of the latter define a new decomposition of the moduli spaces of Riemann surfaces with punctures and boundaries based on quadratic differentials with both first order and second order poles

  12. Axiomatic conformal field theory

    International Nuclear Information System (INIS)

    Gaberdiel, M.R.; Goddard, P.

    2000-01-01

    A new rigourous approach to conformal field theory is presented. The basic objects are families of complex-valued amplitudes, which define a meromorphic conformal field theory (or chiral algebra) and which lead naturally to the definition of topological vector spaces, between which vertex operators act as continuous operators. In fact, in order to develop the theory, Moebius invariance rather than full conformal invariance is required but it is shown that every Moebius theory can be extended to a conformal theory by the construction of a Virasoro field. In this approach, a representation of a conformal field theory is naturally defined in terms of a family of amplitudes with appropriate analytic properties. It is shown that these amplitudes can also be derived from a suitable collection of states in the meromorphic theory. Zhu's algebra then appears naturally as the algebra of conditions which states defining highest weight representations must satisfy. The relationship of the representations of Zhu's algebra to the classification of highest weight representations is explained. (orig.)

  13. Effective field theories

    CERN Document Server

    Petrov, Alexey A

    2016-01-01

    This book is a broad-based text intended to help the growing student body interested in topics such as gravitational effective theories, supersymmetric effective theories, applications of effective theory techniques to problems in condensed matter physics (superconductivity) and quantum chromodynamics (such as soft-collinear effective theory). It begins with a review of the use of symmetries to identify the relevant degrees of freedom in a problem, and then presents a variety of methods that can be used to solve physical problems. A detailed discussion of canonical examples of effective field theories with increasing complexity is then conducted. Special cases such as supersymmetry and lattice EFT are discussed, as well as recently-found applications to problems in gravitation and cosmology. An appendix includes various factoids from group theory and other topics that are used throughout the text, in an attempt to make the book self-contained.

  14. Bookshelf (An Introduction to Quantum field theory, by G. Sterman)

    International Nuclear Information System (INIS)

    Nason, Paolo

    1994-01-01

    This book contains a systematic presentation of quantum field theory. Canonical quantization, path integrals, non-abelian gauge theories, renormalization and axial anomalies are discussed to a satisfactory level, so that the book can be easily used for an introductory course in field theory. The most interesting aspect of the book is contained in Part IV, with a full treatment of soft and collinear singularities, together with a discussion of the meaning of perturbative cross-sections when soft and infrared divergences are present. This subject is too often neglected in textbooks, in spite of the fact that a large amount of current research in high energy physics (and much of the motivation for QCD as a theory for strong interactions) is based on it. The author is certainly a great expert in this field, to which he has brought many important contributions. The core of Part IV is a demonstration of the infrared finiteness of jet crosssections in electron-positron annihilation. Following this, the more complex topic of hadron-initiated reactions involving hadrons in the initial state is dealt with. The physics of scaling violation in both the parton model and in terms of the operator product expansion is discussed. The computation of first order corrections to deep inelastic scattering and to the Drell-Yan pair production process, which marks the beginning of the application of perturbative QCD to hadronic collisions, is given in detail, illustrating the factorization of the hadronic cross-section into a short distance cross-section and a universal parton density. One apparent limitation of the book is its lack of explicit contact with phenomenology. Comparison of theoretical calculations with experimental results are never mentioned (the only graphs one finds in the book are Feynman graphs). The book is therefore mainly aimed at theoretical physicists. However field theory courses are generally paralleled or followed by a course in particle physics phenomenology

  15. Quantum theory of fields

    CERN Document Server

    Wentzel, Gregor

    1949-01-01

    A prominent figure in twentieth-century physics, Gregor Wentzel made major contributions to the development of quantum field theory, first in Europe and later at the University of Chicago. His Quantum Theory of Fields offers a knowledgeable view of the original literature of elementary quantum mechanics and helps make these works accessible to interested readers.An introductory volume rather than an all-inclusive account, the text opens with an examination of general principles, without specification of the field equations of the Lagrange function. The following chapters deal with particular

  16. Mean field dynamics and color conductivity of cold and dense quark matter

    International Nuclear Information System (INIS)

    Zhang Chao; Zheng Xiaoping

    2002-01-01

    The authors first review the non-Abelian transport theory and its mean field dynamics. The theory is then applied for studying the color electric dynamics of cold and dense quark matter at large chemical potential, and color conductivity with non-perturbation effect is obtained. Finally, the authors compare the results at large chemical potential with that at high temperature, and discuss possible applications in the field of astrophysics

  17. Theoretical physics. Field theory

    International Nuclear Information System (INIS)

    Landau, L.; Lifchitz, E.

    2004-01-01

    This book is the fifth French edition of the famous course written by Landau/Lifchitz and devoted to both the theory of electromagnetic fields and the gravity theory. The talk of the theory of electromagnetic fields is based on special relativity and relates to only the electrodynamics in vacuum and that of pointwise electric charges. On the basis of the fundamental notions of the principle of relativity and of relativistic mechanics, and by using variational principles, the authors develop the fundamental equations of the electromagnetic field, the wave equation and the processes of emission and propagation of light. The theory of gravitational fields, i.e. the general theory of relativity, is exposed in the last five chapters. The fundamentals of the tensor calculus and all that is related to it are progressively introduced just when needed (electromagnetic field tensor, energy-impulse tensor, or curve tensor...). The worldwide reputation of this book is generally allotted to clearness, to the simplicity and the rigorous logic of the demonstrations. (A.C.)

  18. Introduction to gauge field theory

    International Nuclear Information System (INIS)

    Bailin, David; Love, Alexander

    1986-01-01

    The book is intended as an introduction to gauge field theory for the postgraduate student of theoretical particle physics. The topics discussed in the book include: path integrals, classical and quantum field theory, scattering amplitudes, feynman rules, renormalisation, gauge field theories, spontaneous symmetry breaking, grand unified theory, and field theories at finite temperature. (UK)

  19. Quantum fields in the non-perturbative regime. Yang-Mills theory and gravity

    Energy Technology Data Exchange (ETDEWEB)

    Eichhorn, Astrid

    2011-09-06

    In this thesis we study candidates for fundamental quantum field theories, namely non-Abelian gauge theories and asymptotically safe quantum gravity. Whereas the first ones have a stronglyinteracting low-energy limit, the second one enters a non-perturbative regime at high energies. Thus, we apply a tool suited to the study of quantum field theories beyond the perturbative regime, namely the Functional Renormalisation Group. In a first part, we concentrate on the physical properties of non-Abelian gauge theories at low energies. Focussing on the vacuum properties of the theory, we present an evaluation of the full effective potential for the field strength invariant F{sub {mu}}{sub {nu}}F{sup {mu}}{sup {nu}} from non-perturbative gauge correlation functions and find a non-trivial minimum corresponding to the existence of a dimension four gluon condensate in the vacuum. We also relate the infrared asymptotic form of the {beta} function of the running background-gauge coupling to the asymptotic behavior of Landau-gauge gluon and ghost propagators and derive an upper bound on their scaling exponents. We then consider the theory at finite temperature and study the nature of the confinement phase transition in d = 3+1 dimensions in various non-Abelian gauge theories. For SU(N) with N= 3,..,12 and Sp(2) we find a first-order phase transition in agreement with general expectations. Moreover our study suggests that the phase transition in E(7) Yang-Mills theory also is of first order. Our studies shed light on the question which property of a gauge group determines the order of the phase transition. In a second part we consider asymptotically safe quantum gravity. Here, we focus on the Faddeev-Popov ghost sector of the theory, to study its properties in the context of an interacting UV regime. We investigate several truncations, which all lend support to the conjecture that gravity may be asymptotically safe. In a first truncation, we study the ghost anomalous dimension

  20. Gauge field theory

    International Nuclear Information System (INIS)

    Aref'eva, I.Ya.; Slavnov, A.A.

    1981-01-01

    This lecture is devoted to the discussion of gauge field theory permitting from the single point of view to describe all the interactions of elementary particles. The authors used electrodynamics and the Einstein theory of gravity to search for a renormgroup fixing a form of Lagrangian. It is shown that the gauge invariance added with the requirement of the minimum number of arbitraries in Lagrangian fixes unambigously the form of the electromagnetic interaction. The generalization of this construction for more complicate charge spaces results in the Yang-Mills theory. The interaction form in this theory is fixed with the relativity principle in the charge space. A quantum scheme of the Yang-Mills fields through the explicit separation of true dynamic variables is suggested. A comfortable relativistically invariant diagram technique for the calculation of a producing potential for the Green functions is described. The Ward generalized identities have been obtained and a procedure of the elimination of ultraviolet and infrared divergencies has been accomplished. Within the framework of QCD (quantum-chromodynamic) the phenomenon of the asymptotic freedom being the most successful prediction of the gauge theory of strong interactions was described. Working methods with QCD outside the framework of the perturbation theory have been described from a coupling constant. QCD is represented as a single theory possessing both the asymptotical freedom and the freedom retaining quarks [ru

  1. Theory of electromagnetic fields

    CERN Document Server

    Wolski, Andrzej

    2011-01-01

    We discuss the theory of electromagnetic fields, with an emphasis on aspects relevant to radiofrequency systems in particle accelerators. We begin by reviewing Maxwell's equations and their physical significance. We show that in free space, there are solutions to Maxwell's equations representing the propagation of electromagnetic fields as waves. We introduce electromagnetic potentials, and show how they can be used to simplify the calculation of the fields in the presence of sources. We derive Poynting's theorem, which leads to expressions for the energy density and energy flux in an electromagnetic field. We discuss the properties of electromagnetic waves in cavities, waveguides and transmission lines.

  2. Theories of Leptonic Flavor

    DEFF Research Database (Denmark)

    Hagedorn, Claudia

    2017-01-01

    I discuss different theories of leptonic flavor and their capability of describing the features of the lepton sector, namely charged lepton masses, neutrino masses, lepton mixing angles and leptonic (low and high energy) CP phases. In particular, I show examples of theories with an abelian flavor...... symmetry G_f, with a non-abelian G_f as well as theories with non-abelian G_f and CP....

  3. Euclidean quantum field theory

    International Nuclear Information System (INIS)

    Jaffe, A.

    1985-01-01

    In four seminal papers, written from 1963 to 1968, Kurt Symanzik laid the foundations for his euclidean quantum field theory program (EQFT). His original goal was to use EQFT as a tool to approach the existence question for interacting quantum fields. In 1968, when other methods appeared better suited for the existence question, Symanzik abandoned this heroic attempt and redirected his research toward different questions. (orig./HSI)

  4. Quantum Field Theory

    CERN Document Server

    Zeidler, Eberhard

    This is the first volume of a modern introduction to quantum field theory which addresses both mathematicians and physicists ranging from advanced undergraduate students to professional scientists. The book tries to bridge the existing gap between the different languages used by mathematicians and physicists. For students of mathematics it is shown that detailed knowledge of the physical background helps to motivate the mathematical subjects and to discover interesting interrelationships between quite different mathematical topics. For students of physics, fairly advanced mathematics is presented, which is beyond the usual curriculum in physics. It is the author's goal to present the state of the art of realizing Einstein's dream of a unified theory for the four fundamental forces in the universe (gravitational, electromagnetic, strong, and weak interaction). From the reviews: "… Quantum field theory is one of the great intellectual edifices in the history of human thought. … This volume differs from othe...

  5. Microcontinuum field theories

    CERN Document Server

    Eringen, A Cemal

    1999-01-01

    Microcontinuum field theories constitute an extension of classical field theories -- of elastic bodies, deformations, electromagnetism, and the like -- to microscopic spaces and short time scales. Material bodies are here viewed as collections of large numbers of deformable particles, much as each volume element of a fluid in statistical mechanics is viewed as consisting of a large number of small particles for which statistical laws are valid. Classical continuum theories are valid when the characteristic length associated with external forces or stimuli is much larger than any internal scale of the body under consideration. When the characteristic lengths are comparable, however, the response of the individual constituents becomes important, for example, in considering the fluid or elastic properties of blood, porous media, polymers, liquid crystals, slurries, and composite materials. This volume is concerned with the kinematics of microcontinua. It begins with a discussion of strain, stress tensors, balanc...

  6. Mean distribution approach to spin and gauge theories

    CERN Document Server

    Akerlund, Oscar

    2016-01-01

    We formulate self-consistency equations for the distribution of links in spin models and of plaquettes in gauge theories. This improves upon known mean-field, mean-link, and mean-plaquette approximations in such that we self-consistently determine all moments of the considered variable instead of just the first. We give examples in both Abelian and non-Abelian cases.

  7. Introduction to string field theory

    International Nuclear Information System (INIS)

    Horowitz, G.T.

    1989-01-01

    A light cone gauge superstring field theory is constructed. The BRST approach is described discussing generalizations to yield gauge invariant free superstring field theory and interacting theory for superstrings. The interaction term is explicitly expressed in terms of first quantized oscillators. A purily cubic action for superstring field theory is also derived. (author)

  8. Solitonic Integrable Perturbations of Parafermionic Theories

    CERN Document Server

    Fernández-Pousa, C R; Hollowood, Timothy J; Miramontes, J L

    1997-01-01

    The quantum integrability of a class of massive perturbations of the parafermionic conformal field theories associated to compact Lie groups is established by showing that they have quantum conserved densities of scale dimension 2 and 3. These theories are integrable for any value of a continuous vector coupling constant, and they generalize the perturbation of the minimal parafermionic models by their first thermal operator. The classical equations-of-motion of these perturbed theories are the non-abelian affine Toda equations which admit (charged) soliton solutions whose semi-classical quantization is expected to permit the identification of the exact S-matrix of the theory.

  9. Superstring field theory

    International Nuclear Information System (INIS)

    Green, M.B.

    1984-01-01

    Superstring field theories are formulated in terms of light-cone-gauge superfields that are functionals of string coordinates chi(sigma) and theta(sigma). The formalism used preserves only the manifest SU(4) symmetry that corresponds to rotations among six of the eight transverse directions. In type I theories, which have one ten-dimensional supersymmetry and describe both open and closed strings, there are five interaction terms of two basic kinds. One kind is a breaking or joining interaction, which is a string generalization of a cubic Yang-Mills coupling. It is relevant to both the three open-string vertex and the open-string to closed-string transition vertex. The other kind is an exchange or crossing-over interaction, which is a string generalization of a cubic gravitational coupling. All the interactions can be uniquely determined by requiring continuity of the coordinates chi(sigma) and theta(sigma) (which implies local conservation of the conjugate momenta) and by imposing the global supersymmetry algebra. Specific local operators are identified for each of the two kinds of interactions. In type II theories, which have two ten-dimensional supersymmetries and contain closed strings only, the entire interaction hamiltonian consists of a single cubic vertex. The higher-order contact terms of the N=8 supergravity theory that arises in the low-energy limit give an effective description of the exchange of massive string modes. (orig.)

  10. Beyond mean field theory: statistical field theory for neural networks.

    Science.gov (United States)

    Buice, Michael A; Chow, Carson C

    2013-03-01

    Mean field theories have been a stalwart for studying the dynamics of networks of coupled neurons. They are convenient because they are relatively simple and possible to analyze. However, classical mean field theory neglects the effects of fluctuations and correlations due to single neuron effects. Here, we consider various possible approaches for going beyond mean field theory and incorporating correlation effects. Statistical field theory methods, in particular the Doi-Peliti-Janssen formalism, are particularly useful in this regard.

  11. Quantum electrodynamics in strong external fields

    International Nuclear Information System (INIS)

    Mueller, B.; Rafelski, J.; Kirsch, J.

    1981-05-01

    We review the theoretical description of quantum electrodynamics in the presence of strong and supercritical fields. In particular, the process of the spontaneous vacuum decay accompanied by the observable positron emission in heavy ion collisions is described. Emphasis is put on the proper formulation of many-body aspects in the framework of quantum field theory. The extension of the theory to the description of Bose fields and many-body effects is presented, and the Klein paradox is resolved. Some implications of the theoretical methods developed here are presented concerning non-abelian gauge theories and the quark confinement puzzle. (orig.)

  12. Thermal Field Theory in Equilibrium

    OpenAIRE

    Andersen, Jens O.

    2000-01-01

    In this talk, I review recent developments in equilibrium thermal field theory. Screened perturbation theory and hard-thermal-loop perturbation theory are discussed. A self-consistent $\\Phi$-derivable approach is also briefly reviewed.

  13. Blockspin renormalization-group study of color confinement due to violation of the non-Abelian Bianchi identity

    Science.gov (United States)

    Suzuki, Tsuneo

    2018-02-01

    Blockspin transformation of topological defects is applied to the violation of the non-Abelian Bianchi identity (VNABI) on lattice defined as Abelian monopoles. To get rid of lattice artifacts, we introduce (1) smooth gauge fixings such as the maximal center gauge (MCG), (2) blockspin transformations and (3) the tadpole-improved gauge action. The effective action can be determined by adopting the inverse Monte Carlo method. The coupling constants F (i ) of the effective action depend on the coupling of the lattice action β and the number of the blocking step n . But it is found that F (i ) satisfies a beautiful scaling; that is, they are a function of the product b =n a (β ) alone for lattice coupling constants 3.0 ≤β ≤3.9 and the steps of blocking 1 ≤n ≤12 . The effective action showing the scaling behavior can be regarded as an almost perfect action corresponding to the continuum limit, since a →0 as n →∞ for fixed b . The infrared effective monopole action keeps the global color invariance when smooth gauges such as MCG keeping the invariance are adopted. The almost perfect action showing the scaling is found to be independent of the smooth gauges adopted here as naturally expected from the gauge invariance of the continuum theory. Then we compare the results with those obtained by the analytic blocking method of topological defects from the continuum, assuming local two-point interactions are dominant as the infrared effective action. The action is formulated in the continuum limit while the couplings of these actions can be derived from simple observables calculated numerically on lattices with a finite lattice spacing. When use is made of Berezinskii-Kosterlitz-Thouless (BKT) transformation, the infrared monopole action can be transformed into that of the string model. Since large b =n a (β ) corresponds to the strong-coupling region in the string model, the physical string tension and the lowest glueball mass can be evaluated analytically

  14. Class field theory

    CERN Document Server

    Artin, Emil

    2009-01-01

    This classic book, originally published in 1968, is based on notes of a year-long seminar the authors ran at Princeton University. The primary goal of the book was to give a rather complete presentation of algebraic aspects of global class field theory, and the authors accomplished this goal spectacularly: for more than 40 years since its first publication, the book has served as an ultimate source for many generations of mathematicians. In this revised edition, two mathematical additions complementing the exposition in the original text are made. The new edition also contains several new foot

  15. Higgs Effective Field Theories

    CERN Document Server

    2016-01-01

    The main focus of this meeting is to present new theoretical advancements related to effective field theories, evaluate the impact of initial results from the LHC Run2, and discuss proposals for data interpretation/presentation during Run2. A crucial role of the meeting is to bring together theorists from different backgrounds and with different viewpoints and to extend bridges towards the experimental community. To this end, we would like to achieve a good balance between senior and junior speakers, enhancing the visibility of younger scientists while keeping some overview talks.

  16. Multiflavor correlation functions in non-Abelian gauge theories at finite fermion density in two dimensions

    International Nuclear Information System (INIS)

    Christiansen, H.R.; Schaposnik, F.A.

    1996-09-01

    We compute vacuum expectation values of products of fermion bilinear for two-dimensional Quantum Chromodynamics at finite flavored fermion densities. We introduce the chemical potential as an external charge distribution within the path-integral approach and carefully analyse the contribution of different topological sectors to fermion correlators. We show the existence of chiral condensates exhibiting an oscillatory inhomogeneous behavior as a function of a chemical potential matrix. This is exact and goes in the same direction as the behavior found is QCD 4 within the large N approximation. (author). 29 refs., 10 figs

  17. Multiflavor correlation functions in non-Abelian gauge theories at finite fermion density in two dimensions

    Energy Technology Data Exchange (ETDEWEB)

    Christiansen, H.R. [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil); Schaposnik, F.A. [La Plata Univ. Nacional (Argentina). Dept. de Fisica

    1996-09-01

    We compute vacuum expectation values of products of fermion bilinear for two-dimensional Quantum Chromodynamics at finite flavored fermion densities. We introduce the chemical potential as an external charge distribution within the path-integral approach and carefully analyse the contribution of different topological sectors to fermion correlators. We show the existence of chiral condensates exhibiting an oscillatory inhomogeneous behavior as a function of a chemical potential matrix. This is exact and goes in the same direction as the behavior found is QCD{sub 4} within the large N approximation. (author). 29 refs., 10 figs.

  18. SU(2,R)q symmetries of non-Abelian Toda theories

    International Nuclear Information System (INIS)

    Gomes, J.F.; Zimerman, A.H.; Sotkov, G.M.

    1998-03-01

    The classical and quantum algebras of a class of conformal NA-Toda models are studied. It is shown that the SL (2,R) q . Poisson brackets algebra generated by certain chiral and antichiral charges of the nonlocal currents and the global U(1) charge appears as an algebra of the symmetries of these models. (author)

  19. Quantum field theory

    International Nuclear Information System (INIS)

    Mancini, F.

    1986-01-01

    Theoretical physicists, coming from different countries, working on different areas, gathered at Positano: the Proceedings contain all the lectures delivered as well as contributed papers. Many areas of physics are represented, elementary particles in high energy physics, quantum relativity, quantum geometry, condensed matter physics, statistical mechanics; but all works are concerned with the use of the methods of quantum field theory. The first motivation of the meeting was to pay homage to a great physicist and a great friend; it was also an occasion in which theoretical physicists got together to discuss and to compare results in different fields. The meeting was very intimate; the relaxed atmosphere allowed constructive discussions and contributed to a positive exchange of ideas. (orig.)

  20. Digestible quantum field theory

    CERN Document Server

    Smilga, Andrei

    2017-01-01

    This book gives an intermediate level treatment of quantum field theory, appropriate to a reader with a first degree in physics and a working knowledge of special relativity and quantum mechanics. It aims to give the reader some understanding of what QFT is all about, without delving deep into actual calculations of Feynman diagrams or similar. The author serves up a seven‐course menu, which begins with a brief introductory Aperitif. This is followed by the Hors d'oeuvres, which set the scene with a broad survey of the Universe, its theoretical description, and how the ideas of QFT developed during the last century. In the next course, the Art of Cooking, the author recaps on some basic facts of analytical mechanics, relativity, quantum mechanics and also presents some nutritious “extras” in mathematics (group theory at the elementary level) and in physics (theory of scattering). After these preparations, the reader should have a good appetite for the Entrées ‐ the central par t of the book where the...

  1. High-energy behavior of fermion-meson and meson-meson scattering in a supersymmetric field theory

    International Nuclear Information System (INIS)

    Opoien, J.W.

    1978-01-01

    The high-energy behavior of fermion-boson and boson-boson scattering amplitudes of a supersymmetric field theory containing a spin-1/2 fermion field, a scalar field, and a pseudoscalar field is investigated. The results can be easily modified to apply to the Yukawa model and the neutral version of the linear sigma model. The results are also compared to those of fermion-fermion scattering in the same model. In the leading-logarithm approximation, ladders with fermions running along the sides in the t channel and mesons as rungs dominate in each order of two classes of diagrams. The sum of the dominant series give rise to fixed Regge cuts for all amplitudes in each of the three theories. All amplitudes in the supersymmetric theory possess a definite signature factor, while the amplitudes for fermion-fermion and fermion-antifermion scattering in the Y model and the sigma model lack it. The results of the supersymmetric theory are also compared to the results of the spontaneously broken non-Abelian gauge theory

  2. Boundaries and defects of SYM with 4 supercharges. Part II: Brane constructions and 3 d field theories

    Science.gov (United States)

    Hashimoto, Akikazu; Ouyang, Peter; Yamazaki, Masahito

    2014-10-01

    We study the vacuum moduli spaces of 3 d supersymmetric quantum field theories by applying the formalism developed in our previous paper [1]. The 3 d theories can be realized by branes in type IIB string theory, which in a decoupling limit reduce to 4 d super-Yang-Mills theory on an interval with BPS defects inserted. The moduli space of a given 3 d theory is obtained by solving a generalization of Nahm's equations with appropriate boundary/junction conditions, along with help from the S-duality of type IIB string theory. Our classical computations reproduce many known results about the quantum-corrected moduli spaces of 3 d theories, e.g. U( N c ) theories with N f flavors with mass and FI parameters turned on. In particular, our methods give first-principles derivations of several results in the literature, including the s-rule, quantum splitting of classical Coulomb branches, the lifting of the Coulomb branch by non-Abelian instantons, quantum merging of Coulomb and Higgs branches, and phase transitions from re-ordering 5-branes.

  3. Theory of interacting quantum fields

    International Nuclear Information System (INIS)

    Rebenko, Alexei L.

    2012-01-01

    This monograph is devoted to the systematic presentation of foundations of the quantum field theory. Unlike numerous monographs devoted to this topic, a wide range of problems covered in this book are accompanied by their sufficiently clear interpretations and applications. An important significant feature of this monograph is the desire of the author to present mathematical problems of the quantum field theory with regard to new methods of the constructive and Euclidean field theory that appeared in the last thirty years of the 20 th century and are based on the rigorous mathematical apparatus of functional analysis, the theory of operators, and the theory of generalized functions. The monograph is useful for students, post-graduate students, and young scientists who desire to understand not only the formality of construction of the quantum field theory but also its essence and connection with the classical mechanics, relativistic classical field theory, quantum mechanics, group theory, and the theory of path integral formalism.

  4. Topics in quantum field theory

    International Nuclear Information System (INIS)

    Svaiter, N.F.

    2006-11-01

    This paper presents some important aspects on quantum field theory, covering the following aspects: the triumph and limitations of the quantum field theory; the field theory in curved spaces - Hawking and Unruh-Davies effects; the problem of divergent theory of the zero-point; the problem of the spinning detector and the Trocheries-Takeno vacuum; the field theory at finite temperature - symmetry breaking and phase transition; the problem of the summability of the perturbative series and the perturbative expansion for the strong coupling; quantized fields in presence of classical macroscopic structures; the Parisi-Wu stochastic quantization method

  5. Fractional Stochastic Field Theory

    Science.gov (United States)

    Honkonen, Juha

    2018-02-01

    Models describing evolution of physical, chemical, biological, social and financial processes are often formulated as differential equations with the understanding that they are large-scale equations for averages of quantities describing intrinsically random processes. Explicit account of randomness may lead to significant changes in the asymptotic behaviour (anomalous scaling) in such models especially in low spatial dimensions, which in many cases may be captured with the use of the renormalization group. Anomalous scaling and memory effects may also be introduced with the use of fractional derivatives and fractional noise. Construction of renormalized stochastic field theory with fractional derivatives and fractional noise in the underlying stochastic differential equations and master equations and the interplay between fluctuation-induced and built-in anomalous scaling behaviour is reviewed and discussed.

  6. Chameleon field theories

    International Nuclear Information System (INIS)

    Khoury, Justin

    2013-01-01

    Chameleons are light scalar fields with remarkable properties. Through the interplay of self-interactions and coupling to matter, chameleon particles have a mass that depends on the ambient matter density. The manifestation of the fifth force mediated by chameleons therefore depends sensitively on their environment, which makes for a rich phenomenology. In this paper, we review two recent results on chameleon phenomenology. The first result a pair of no-go theorems limiting the cosmological impact of chameleons and their generalizations: (i) the range of the chameleon force at cosmological density today can be at most ∼Mpc; (ii) the conformal factor relating Einstein- and Jordan-frame scale factors is essentially constant over the last Hubble time. These theorems imply that chameleons have negligible effect on the linear growth of structure, and cannot account for the observed cosmic acceleration except as some form of dark energy. The second result pertains to the quantum stability of chameleon theories. We show how requiring that quantum corrections be small, so as to allow reliable predictions of fifth forces, leads to an upper bound of m −3 ) 1/3 eV for gravitational strength coupling, whereas fifth force experiments place a lower bound of m > 0.0042 eV. An improvement of less than a factor of 2 in the range of fifth force experiments could test all classical chameleon field theories whose quantum corrections are well-controlled and couple to matter with nearly gravitational strength regardless of the specific form of the chameleon potential. (paper)

  7. Higher spin gauge theories

    CERN Document Server

    Henneaux, Marc; Vasiliev, Mikhail A

    2017-01-01

    Symmetries play a fundamental role in physics. Non-Abelian gauge symmetries are the symmetries behind theories for massless spin-1 particles, while the reparametrization symmetry is behind Einstein's gravity theory for massless spin-2 particles. In supersymmetric theories these particles can be connected also to massless fermionic particles. Does Nature stop at spin-2 or can there also be massless higher spin theories. In the past strong indications have been given that such theories do not exist. However, in recent times ways to evade those constraints have been found and higher spin gauge theories have been constructed. With the advent of the AdS/CFT duality correspondence even stronger indications have been given that higher spin gauge theories play an important role in fundamental physics. All these issues were discussed at an international workshop in Singapore in November 2015 where the leading scientists in the field participated. This volume presents an up-to-date, detailed overview of the theories i...

  8. Quantum field theory of fluids.

    Science.gov (United States)

    Gripaios, Ben; Sutherland, Dave

    2015-02-20

    The quantum theory of fields is largely based on studying perturbations around noninteracting, or free, field theories, which correspond to a collection of quantum-mechanical harmonic oscillators. The quantum theory of an ordinary fluid is "freer", in the sense that the noninteracting theory also contains an infinite collection of quantum-mechanical free particles, corresponding to vortex modes. By computing a variety of correlation functions at tree and loop level, we give evidence that a quantum perfect fluid can be consistently formulated as a low-energy, effective field theory. We speculate that the quantum behavior is radically different from both classical fluids and quantum fields.

  9. Bethe ansatz solution of an integrable, non-Abelian anyon chain with D(D{sub 3}) symmetry

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, C.W.; Dancer, K.A.; Isaac, P.S. [Centre for Mathematical Physics, School of Mathematics and Physics, The University of Queensland, 4072 (Australia); Links, J., E-mail: jrl@maths.uq.edu.a [Centre for Mathematical Physics, School of Mathematics and Physics, The University of Queensland, 4072 (Australia)

    2010-09-11

    The exact solution for the energy spectrum of a one-dimensional Hamiltonian with local two-site interactions and periodic boundary conditions is determined. The two-site Hamiltonians commute with the symmetry algebra given by the Drinfeld double D(D{sub 3}) of the dihedral group D{sub 3}. As such the model describes local interactions between non-Abelian anyons, with fusion rules given by the tensor product decompositions of the irreducible representations of D(D{sub 3}). The Bethe ansatz equations which characterise the exact solution are found through the use of functional relations satisfied by a set of mutually commuting transfer matrices.

  10. Non-perturbative aspects of quantum field theory. From the quark-gluon plasma to quantum gravity

    Energy Technology Data Exchange (ETDEWEB)

    Christiansen, Nicolai

    2015-07-08

    In this dissertation we investigate several aspects of non-perturbative quantum field theory. Two main parts of the thesis are concerned with non-perturbative renormalization of quantum gravity within the asymptotic safety scenario. This framework is based on a non-Gaussian ultraviolet fixed point and provides a well-defined theory of quantized gravity. We employ functional renormalization group (FRG) techniques that allow for the study of quantum fields even in strongly coupled regimes. We construct a setup for the computation of graviton correlation functions and analyze the ultraviolet completion of quantum gravity in terms of the properties of the two- and three point function of the graviton. Moreover, the coupling of gravity to Yang-Mills theories is discussed. In particular, we study the effects of graviton induced interactions on asymptotic freedom on the one hand, and the role of gluonic fluctuations in the gravity sector on the other hand. The last subject of this thesis is the physics of the quark-gluon plasma. We set-up a general non-perturbative strategy for the computation of transport coefficients in non-Abelian gauge theories. We determine the viscosity over entropy ratio η/s in SU(3) Yang-Mills theory as a function of temperature and estimate its behavior in full quantum chromodynamics (QCD).

  11. Asymptotically flat, stable black hole solutions in Einstein-Yang-Mills-Chern-Simons theory.

    Science.gov (United States)

    Brihaye, Yves; Radu, Eugen; Tchrakian, D H

    2011-02-18

    We construct finite mass, asymptotically flat black hole solutions in d=5 Einstein-Yang-Mills-Chern-Simons theory. Our results indicate the existence of a second order phase transition between Reissner-Nordström solutions and the non-Abelian black holes which generically are thermodynamically preferred. Some of the non-Abelian configurations are also stable under linear, spherically symmetric perturbations.

  12. Studying critical string emerging from non-Abelian vortex in four dimensions

    Directory of Open Access Journals (Sweden)

    P. Koroteev

    2016-08-01

    We study the above vortex string from the standpoint of string theory, focusing on the massless states in four dimensions. In the generic case all massless modes are non-normalizable, hence, no massless gravitons or vector fields are predicted in the physical spectrum. However, at the selfdual point (at strong coupling weighted CP(2,2 admits deformation of the complex structure, resulting in a single massless hypermultiplet in the bulk. We interpret it as a composite “baryon.”

  13. Non-Abelian quantum order in spin-orbit-coupled semiconductors: Search for topological Majorana particles in solid-state systems

    Science.gov (United States)

    Sau, Jay D.; Tewari, Sumanta; Lutchyn, Roman M.; Stanescu, Tudor D.; Das Sarma, S.

    2010-12-01

    We show that an ordinary semiconducting thin film with spin-orbit coupling can, under appropriate circumstances, be in a quantum topologically ordered state supporting exotic Majorana excitations which follow non-Abelian statistics. The key to the quantum topological order is the coexistence of spin-orbit coupling with proximity-induced s -wave superconductivity and an externally induced Zeeman coupling of the spins. For the Zeeman coupling below a critical value, the system is a nontopological (proximity-induced) s -wave superconductor. However, for a range of Zeeman coupling above the critical value, the lowest energy excited state inside a vortex is a zero-energy Majorana fermion state. The system, thus, has entered into a non-Abelian s -wave superconducting state via a topological quantum phase transition (TQPT) tuned by the Zeeman coupling. In the topological phase, since the time-reversal symmetry is explicitly broken by the Zeeman term in the Hamiltonian, the edge of the film constitutes a chiral Majorana wire. Just like the s -wave superconductivity, the Zeeman coupling can also be proximity induced in the film by an adjacent magnetic insulator. We show this by an explicit model tight-binding calculation for both types of proximity effects in the heterostructure geometry. Here we show that the same TQPT can be accessed by varying the interface transparency between the film and the superconductor. For the transparency below (above) a critical value, the system is a topological (regular) s -wave superconductor. In the one-dimensional version of the same structure and for the Zeeman coupling above the critical value, there are localized Majorana zero-energy modes at the two ends of a semiconducting quantum nanowire. In this case, the Zeeman coupling can be induced more easily by an external magnetic field parallel to the wire, obviating the need for a magnetic insulator. We show that, despite the fact that the superconducting pair potential in the nanowire is

  14. A Modern Introduction to Quantum Field Theory (Oxford Master Series in Physics)

    Energy Technology Data Exchange (ETDEWEB)

    Straumann, N [Universitaet Zuerich (Switzerland)

    2005-06-21

    This new book on quantum field theory by Michele Maggiore fits well into the Oxford Master Series in Physics, which is designed for final year undergraduate and beginning graduate students in physics. It is based on the teaching experience of the author with students in the fourth year at the University of Geneva. In this sense it is a two-semester course book for students exposed to quantum field theory for the first time. Maggiore gives, on slightly less than 300 pages, a balanced introduction to a vast field of twentieth century physics that will help students going on to study more advanced and specialized courses. Beside applications to many processes in particle physics that can also be found in many other textbooks, the author emphasizes conceptual, structural and methodological aspects of quantum field theory. After an introductory chapter, the group theoretical tools required to implement Lorentz invariance in quantum field theory are developed on 30 pages. Chapter 3 is devoted to classical field theory, emphasizing symmetries and conservation laws. The quantization of free fields in the next chapter follows traditional lines. Here one may miss a section describing the mathematical structure of the Fock space. It is also not said that in infinite dimensions von Neumann's uniqueness theorem for the representations of the canonical commutation relations no longer holds. The operations C, P, T are carefully discussed. In the relatively long chapter 5, perturbation theory and renormalization are developed. In this context the author discusses the modern view on renormalizability, and also emphasizes in a separate section the seriousness of the cosmological constant problem in quantum field theory. The next three chapters provide applications of the theory, especially to quantum electrodynamics and the low-energy limit of the electroweak theory. Chapters 9, 10, and 11 are meant as a bridge to more advanced courses. In these, path integral quantization, non-Abelian

  15. Naturality in conformal field theory

    International Nuclear Information System (INIS)

    Moore, G.; Seiberg, N.

    1989-01-01

    We discuss constraints on the operator product coefficients in diagonal and nondiagonal rational conformal field theories. Nondiagonal modular invariants always arise from automorphisms of the fusion rule algebra or from extensions of the chiral algebra. Moreover, when the chiral algebra has been maximally extended a strong form of the naturality principle of field theory can be proven for rational conformal field theory: operator product coefficients vanish if and only if the corresponding fusion rules vanish; that is, if and only if the vanishing can be understood in terms of a symmetry. We illustrate these ideas with several examples. We also generalize our ideas about rational conformal field theories to a larger class of theories: 'quasi-rational conformal field theories' and we explore some of their properties. (orig.)

  16. A Yang-Mills Theory in Loop Space and Generalized Chapline-Manton Coupling

    OpenAIRE

    Tadahito, NAKAJIMA; Physics Laboratory, College of Science and Technology, Nihon University

    2001-01-01

    We consider a Yang-Mills theory in loop space with an affine Lie gauge group. The Chapline-Manton coupling, the coupling between Yang-Mills fields and an abelian antisymmetric tensor field of second rank via the Chern-Simons term, is systematically derived within the framework of the Yang-Mills theory. The generalized Chapline-Manton couplings, the couplings among non-abelian tensor fields of second rank, Yang-Mills fields, and an abelian tensor field of third rank, are also derived by applyi...

  17. A Yang-Mills Theory in Loop Space and Generalized Chapline-Manton Coupling

    OpenAIRE

    Nakajima, Tadahito

    2000-01-01

    We consider a Yang-Mills theory in loop space with an affine Lie gauge group. The Chapline-Manton coupling, the coupling between Yang-Mills fields and an abelian antisymmetric tensor field of second rank via the Chern-Simons term, is systematically derived within the framework of the Yang-Mills theory. The generalized Chapline-Manton couplings, the couplings among non-abelian tensor fields of second rank, Yang-Mills fields, and an abelian tensor field of third rank, are also derived by applyi...

  18. Classical and quantum electrodynamics and the B(3) field

    CERN Document Server

    Evans, Myron W

    2001-01-01

    It is well known that classical electrodynamics is riddled with internal inconsistencies springing from the fact that it is a linear, Abelian theory in which the potentials are unphysical. This volume offers a self-consistent hypothesis which removes some of these problems, as well as builds a framework on which linear and nonlinear optics are treated as a non-Abelian gauge field theory based on the emergence of the fundamental magnetizing field of radiation, the B(3) field. Contents: Interaction of Electromagnetic Radiation with One Fermion; The Field Equations of Classical O (3) b Electrodyn

  19. Abelian and non-Abelian anyons in integer quantum anomalous Hall effect and topological phase transitions via superconducting proximity effect

    Science.gov (United States)

    Liu, Xuele; Wang, Ziqiang; Xie, X. C.; Yu, Yue

    2011-03-01

    We study the quantum anomalous Hall effect described by a class of two-component Haldane models on square lattices. We show that the latter can be transformed into a pseudospin triplet p+ip-wave paired superfluid. In the long wavelength limit, the ground-state wave function is described by Halperin’s (1,1,-1) state of neutral fermions analogous to the double-layer quantum Hall effect. The vortex excitations are charge e/2 Abelian anyons which carry a neutral Dirac fermion zero mode. The superconducting proximity effect induces “tunneling” between “layers” which leads to topological phase transitions whereby the Dirac fermion zero mode fractionalizes and Majorana fermions emerge in the edge states. The charge e/2 vortex excitation carrying a Majorana zero mode is a non-Abelian anyon. The proximity effect can also drive a conventional insulator into a quantum anomalous Hall effect state with a Majorana edge mode and the non-Abelian vortex excitations.

  20. Field theory and particle physics

    International Nuclear Information System (INIS)

    Eboli, O.J.P.; Gomes, M.; Santoro, A.

    1990-01-01

    This book contains the proceedings of the topics covered during the fifth Jorge Andre Swieca Summer School. The first part of the book collects the material devoted to quantum field theory. There were four courses on methods in Field Theory; H. O. Girotti lectured on constrained dynamics, R. Jackiw on the Schrodinger representation in Field Theory, S.-Y. Pi on the application of this representation to quantum fields in a Robertson-Walker spacetime, and L. Vinet on Berry Connections. There were three courses on Conformal Field Theory: I. Todorov focused on the problem of construction and classification of conformal field theories. Lattice models, two-dimensional S matrices and conformal field theory were looked from the unifying perspective of the Yang-Baxter algebras in the lectures given by M. Karowski. Parasupersymmetric quantum mechanics was discussed in the lectures by L. Vinet. Besides those courses, there was an introduction to string field theory given by G. Horowitz. There were also three seminars: F. Schaposnik reported on recent applications of topological methods in field theory, P. Gerbert gave a seminar on three dimensional gravity and V. Kurak talked on two dimensional parafermionic models. The second part of this proceedings is devoted to phenomenology. There were three courses on Particle Physics: Dan Green lectured on collider physics, E. Predrazzi on strong interactions and G. Cohen-Tanoudji on the use of strings in strong interactions

  1. Abelian 2-form gauge theory: special features

    International Nuclear Information System (INIS)

    Malik, R P

    2003-01-01

    It is shown that the four (3 + 1)-dimensional (4D) free Abelian 2-form gauge theory provides an example of (i) a class of field theoretical models for the Hodge theory, and (ii) a possible candidate for the quasi-topological field theory (q-TFT). Despite many striking similarities with some of the key topological features of the two (1 + 1)-dimensional (2D) free Abelian (and self-interacting non-Abelian) gauge theories, it turns out that the 4D free Abelian 2-form gauge theory is not an exact TFT. To corroborate this conclusion, some of the key issues are discussed. In particular, it is shown that the (anti-)BRST and (anti-)co-BRST invariant quantities of the 4D 2-form Abelian gauge theory obey recursion relations that are reminiscent of the exact TFTs but the Lagrangian density of this theory is not found to be able to be expressed as the sum of (anti-)BRST and (anti-)co-BRST exact quantities as is the case with the topological 2D free Abelian (and self-interacting non-Abelian) gauge theories

  2. Class field theory from theory to practice

    CERN Document Server

    Gras, Georges

    2003-01-01

    Global class field theory is a major achievement of algebraic number theory, based on the functorial properties of the reciprocity map and the existence theorem. The author works out the consequences and the practical use of these results by giving detailed studies and illustrations of classical subjects (classes, idèles, ray class fields, symbols, reciprocity laws, Hasse's principles, the Grunwald-Wang theorem, Hilbert's towers,...). He also proves some new or less-known results (reflection theorem, structure of the abelian closure of a number field) and lays emphasis on the invariant (/cal T) p, of abelian p-ramification, which is related to important Galois cohomology properties and p-adic conjectures. This book, intermediary between the classical literature published in the sixties and the recent computational literature, gives much material in an elementary way, and is suitable for students, researchers, and all who are fascinated by this theory. In the corrected 2nd printing 2005, the author improves s...

  3. Broken symmetries in field theory

    NARCIS (Netherlands)

    Kok, Mark Okker de

    2008-01-01

    The thesis discusses the role of symmetries in Quantum Field Theory. Quantum Field Theory is the mathematical framework to describe the physics of elementary particles. A symmetry here means a transformation under which the model at hand is invariant. Three types of symmetry are distinguished: 1.

  4. Field theory approach to gravitation

    International Nuclear Information System (INIS)

    Yilmaz, H.

    1978-01-01

    A number of authors considered the possibility of formulating a field-theory approach to gravitation with the claim that such an approach would uniquely lead to Einstein's theory of general relativity. In this article it is shown that the field theory approach is more generally applicable and uniqueness cannot be claimed. Theoretical and experimental reasons are given showing that the Einsteinian limit appears to be unviable

  5. Renormalization and effective field theory

    CERN Document Server

    Costello, Kevin

    2011-01-01

    This book tells mathematicians about an amazing subject invented by physicists and it tells physicists how a master mathematician must proceed in order to understand it. Physicists who know quantum field theory can learn the powerful methodology of mathematical structure, while mathematicians can position themselves to use the magical ideas of quantum field theory in "mathematics" itself. The retelling of the tale mathematically by Kevin Costello is a beautiful tour de force. --Dennis Sullivan This book is quite a remarkable contribution. It should make perturbative quantum field theory accessible to mathematicians. There is a lot of insight in the way the author uses the renormalization group and effective field theory to analyze perturbative renormalization; this may serve as a springboard to a wider use of those topics, hopefully to an eventual nonperturbative understanding. --Edward Witten Quantum field theory has had a profound influence on mathematics, and on geometry in particular. However, the notorio...

  6. Quantum group gauge theories and covariant quantum algebras

    International Nuclear Information System (INIS)

    Isaev, A.P.

    1993-01-01

    The algebraic formulation of the quantum group gauge models in the framework of the R-matrix approach to the theory of quantum groups is given. Gauge groups taking values in the quantum groups and noncommutative gauge fields transformed as comodules under the coaction of the gauge quantum group G q are considered. Using this approach the quantum deformations of the topological Chern-Simons models, non-Abelian gauge theories and the Einstein gravity are constructed. The noncommutative fields in these models generate G q -covariant quantum algebras. 24 refs

  7. "Wormhole" geometry for entrapping topologically protected qubits in non-abelian quantum hall states and probing them with voltage and noise measurements.

    Science.gov (United States)

    Hou, Chang-Yu; Chamon, Claudio

    2006-10-06

    We study a tunneling geometry defined by a single point-contact constriction that brings to close vicinity two points sitting at the same edge of a quantum Hall liquid, shortening the trip between the otherwise spatially separated points along the normal chiral edge path. This wormhole-like geometry allows for entrapping bulk quasiparticles between the edge path and the tunnel junction, possibly realizing a topologically protected qubit if the quasiparticles have non-Abelian statistics. We show how either noise or simpler voltage measurements along the edge can probe the non-Abelian nature of the trapped quasiparticles.

  8. Semiclassical methods in field theories

    International Nuclear Information System (INIS)

    Ventura, I.

    1978-10-01

    A new scheme is proposed for semi-classical quantization in field theory - the expansion about the charge (EAC) - which is developed within the canonical formalism. This method is suitable for quantizing theories that are invariant under global gauge transformations. It is used in the treatment of the non relativistic logarithmic theory that was proposed by Bialynicki-Birula and Mycielski - a theory we can formulate in any number of spatial dimensions. The non linear Schroedinger equation is also quantized by means of the EAC. The classical logarithmic theories - both, the non relativistic and the relativistic one - are studied in detail. It is shown that the Bohr-Sommerfeld quantization rule(BSQR) in field theory is, in many cases, equivalent to charge quantization. This rule is then applied to the massive Thirring Model and the logarithmic theories. The BSQR can be see as a simplified and non local version of the EAC [pt

  9. Introduction to quantum field theory

    International Nuclear Information System (INIS)

    Kazakov, D.I.

    1988-01-01

    The lectures appear to be a continuation to the introduction to elementary principles of the quantum field theory. The work is aimed at constructing the formalism of standard particle interaction model. Efforts are made to exceed the limits of the standard model in the quantum field theory context. Grand unification models including strong and electrical weak interactions, supersymmetric generalizations of the standard model and grand unification theories and, finally, supergravitation theories including gravitation interaction to the universal scheme, are considered. 3 refs.; 19 figs.; 2 tabs

  10. Lectures on matrix field theory

    CERN Document Server

    Ydri, Badis

    2017-01-01

    These lecture notes provide a systematic introduction to matrix models of quantum field theories with non-commutative and fuzzy geometries. The book initially focuses on the matrix formulation of non-commutative and fuzzy spaces, followed by a description of the non-perturbative treatment of the corresponding field theories. As an example, the phase structure of non-commutative phi-four theory is treated in great detail, with a separate chapter on the multitrace approach. The last chapter offers a general introduction to non-commutative gauge theories, while two appendices round out the text. Primarily written as a self-study guide for postgraduate students – with the aim of pedagogically introducing them to key analytical and numerical tools, as well as useful physical models in applications – these lecture notes will also benefit experienced researchers by providing a reference guide to the fundamentals of non-commutative field theory with an emphasis on matrix models and fuzzy geometries.

  11. A landscape of field theories

    Energy Technology Data Exchange (ETDEWEB)

    Maxfield, Travis [Enrico Fermi Institute, University of Chicago,Chicago, IL 60637 (United States); Robbins, Daniel [George P. and Cynthia W. Mitchell Institute for Fundamental Physics and Astronomy,Texas A& M University,College Station, TX 77843-4242 (United States); Sethi, Savdeep [Enrico Fermi Institute, University of Chicago,Chicago, IL 60637 (United States)

    2016-11-28

    Studying a quantum field theory involves a choice of space-time manifold and a choice of background for any global symmetries of the theory. We argue that many more choices are possible when specifying the background. In the context of branes in string theory, the additional data corresponds to a choice of supergravity tensor fluxes. We propose the existence of a landscape of field theory backgrounds, characterized by the space-time metric, global symmetry background and a choice of tensor fluxes. As evidence for this landscape, we study the supersymmetric six-dimensional (2,0) theory compactified to two dimensions. Different choices of metric and flux give rise to distinct two-dimensional theories, which can preserve differing amounts of supersymmetry.

  12. Gauge and integrable theories in loop spaces

    International Nuclear Information System (INIS)

    Ferreira, L.A.; Luchini, G.

    2012-01-01

    We propose an integral formulation of the equations of motion of a large class of field theories which leads in a quite natural and direct way to the construction of conservation laws. The approach is based on generalized non-abelian Stokes theorems for p-form connections, and its appropriate mathematical language is that of loop spaces. The equations of motion are written as the equality of a hyper-volume ordered integral to a hyper-surface ordered integral on the border of that hyper-volume. The approach applies to integrable field theories in (1+1) dimensions, Chern-Simons theories in (2+1) dimensions, and non-abelian gauge theories in (2+1) and (3+1) dimensions. The results presented in this paper are relevant for the understanding of global properties of those theories. As a special byproduct we solve a long standing problem in (3+1)-dimensional Yang-Mills theory, namely the construction of conserved charges, valid for any solution, which are invariant under arbitrary gauge transformations.

  13. Embedding classical fields in quantum field theories

    International Nuclear Information System (INIS)

    Blaha, S.

    1978-01-01

    We describe a procedure for quantizing a classical field theory which is the field-theoretica analog of Sudarshan's method for embedding a classical-mechanical system in a quantum-mechanical system. The essence of the difference between our quantization procedure and Fock-space quantization lies in the choice of vacuum states. The key to our choice of vacuum is the procedure we outline for constructing Lagrangians which have gradient terms linear in the field varialbes from classical Lagrangians which have gradient terms which are quadratic in field variables. We apply this procedure to model electrodynamic field theories, Yang-Mills theories, and a vierbein model of gravity. In the case of electrodynamics models we find a formalism with a close similarity to the coherent-soft-photon-state formalism of QED. In addition, photons propagate to t = + infinity via retarded propagators. We also show how to construct a quantum field for action-at-a-distance electrodynamics. In the Yang-Mills case we show that a previously suggested model for quark confinement necessarily has gluons with principle-value propagation which allows the model to be unitary despite the presence of higher-order-derivative field equations. In the vierbein-gravity model we show that our quantization procedure allows us to treat the classical and quantum parts of the metric field in a unified manner. We find a new perturbation scheme for quantum gravity as a result

  14. Integrable boundary conditions for a non-Abelian anyon chain with D(D{sub 3}) symmetry

    Energy Technology Data Exchange (ETDEWEB)

    Dancer, K.A.; Finch, P.E.; Isaac, P.S. [The University of Queensland, Centre for Mathematical Physics, School of Physical Sciences, 4072 (Australia); Links, J. [The University of Queensland, Centre for Mathematical Physics, School of Physical Sciences, 4072 (Australia)], E-mail: jrl@maths.uq.edu.au

    2009-05-11

    A general formulation of the Boundary Quantum Inverse Scattering Method is given which is applicable in cases where R-matrix solutions of the Yang-Baxter equation do not have the property of crossing unitarity. Suitably modified forms of the reflection equations are presented which permit the construction of a family of commuting transfer matrices. As an example, we apply the formalism to determine the most general solutions of the reflection equations for a solution of the Yang-Baxter equation with underlying symmetry given by the Drinfeld double D(D{sub 3}) of the dihedral group D{sub 3}. This R-matrix does not have the crossing unitarity property. In this manner we derive integrable boundary conditions for an open chain model of interacting non-Abelian anyons.

  15. Topological field theories and duality

    International Nuclear Information System (INIS)

    Stephany, J.; Universidad Simon Bolivar, Caracas

    1996-05-01

    Topologically non trivial effects appearing in the discussion of duality transformations in higher genus manifold are discussed in a simple example, and their relation with the properties of Topological Field Theories is established. (author). 16 refs

  16. Renormalization in classical field theory

    International Nuclear Information System (INIS)

    Corbo, Guido

    2010-01-01

    We discuss simple examples in which renormalization is required in classical field theory. The presentation is accessible to undergraduate students with a knowledge of the basic notions of classical electromagnetism. (letters and comments)

  17. Finite-temperature field theory

    International Nuclear Information System (INIS)

    Kapusta, J.I.; Landshoff, P.V.

    1989-01-01

    Particle number is not conserved in relativistic theories although both lepton and baryon number are. Therefore when discussing the thermodynamics of a quantum field theory one uses the grand canonical formalism. The entropy S is maximised, keeping fixed the ensemble averages E and N of energy and lepton number. Two lagrange multipliers are introduced. (author)

  18. Supersymmetric field theories and generalized cohomology

    OpenAIRE

    Teichner, Peter; Stolz, Stephan

    2011-01-01

    This survey discusses our results and conjectures concerning supersymmetric field theories and their relationship to cohomology theories. A careful definition of supersymmetric Euclidean field theories is given, refining Segal's axioms for conformal field theories. We state and give an outline of the proof of various results relating field theories to cohomology theories.

  19. Neural fields theory and applications

    CERN Document Server

    Graben, Peter; Potthast, Roland; Wright, James

    2014-01-01

    With this book, the editors present the first comprehensive collection in neural field studies, authored by leading scientists in the field - among them are two of the founding-fathers of neural field theory. Up to now, research results in the field have been disseminated across a number of distinct journals from mathematics, computational neuroscience, biophysics, cognitive science and others. Starting with a tutorial for novices in neural field studies, the book comprises chapters on emergent patterns, their phase transitions and evolution, on stochastic approaches, cortical development, cognition, robotics and computation, large-scale numerical simulations, the coupling of neural fields to the electroencephalogram and phase transitions in anesthesia. The intended readership are students and scientists in applied mathematics, theoretical physics, theoretical biology, and computational neuroscience. Neural field theory and its applications have a long-standing tradition in the mathematical and computational ...

  20. The energy–momentum tensor(s in classical gauge theories

    Directory of Open Access Journals (Sweden)

    Daniel N. Blaschke

    2016-11-01

    Full Text Available We give an introduction to, and review of, the energy–momentum tensors in classical gauge field theories in Minkowski space, and to some extent also in curved space–time. For the canonical energy–momentum tensor of non-Abelian gauge fields and of matter fields coupled to such fields, we present a new and simple improvement procedure based on gauge invariance for constructing a gauge invariant, symmetric energy–momentum tensor. The relationship with the Einstein–Hilbert tensor following from the coupling to a gravitational field is also discussed.

  1. The energy–momentum tensor(s) in classical gauge theories

    Energy Technology Data Exchange (ETDEWEB)

    Blaschke, Daniel N., E-mail: dblaschke@lanl.gov [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Gieres, François, E-mail: gieres@ipnl.in2p3.fr [Institut de Physique Nucléaire de Lyon, Université de Lyon, Université Claude Bernard Lyon 1 and CNRS/IN2P3, Bat. P. Dirac, 4 rue Enrico Fermi, F-69622 Villeurbanne (France); Reboud, Méril, E-mail: meril.reboud@ens-lyon.fr [Institut de Physique Nucléaire de Lyon, Université de Lyon, Université Claude Bernard Lyon 1 and CNRS/IN2P3, Bat. P. Dirac, 4 rue Enrico Fermi, F-69622 Villeurbanne (France); Ecole Normale Supérieure de Lyon, 46 allée d' Italie, F-69364 Lyon CEDEX 07 (France); Schweda, Manfred, E-mail: mschweda@tph.tuwien.ac.at [Institute for Theoretical Physics, Vienna University of Technology, Wiedner Hauptstraße 8-10, A-1040 Vienna (Austria)

    2016-11-15

    We give an introduction to, and review of, the energy–momentum tensors in classical gauge field theories in Minkowski space, and to some extent also in curved space–time. For the canonical energy–momentum tensor of non-Abelian gauge fields and of matter fields coupled to such fields, we present a new and simple improvement procedure based on gauge invariance for constructing a gauge invariant, symmetric energy–momentum tensor. The relationship with the Einstein–Hilbert tensor following from the coupling to a gravitational field is also discussed.

  2. Dimensional continuation in field theory

    International Nuclear Information System (INIS)

    Lee, T.

    1988-01-01

    The continuation of space-time dimension to an arbitrary complex number is discussed. The ultra-violet and infra-red divergences are simply regularized by analytically continuing to some proper dimension n. Combined with functional integral quantization, it provides a simple and elegant description of quantum field theory. Two well known field theories are discussed. Scalar field theory and quantum electrodynamics. In the scalar theory, the focus is on the operator product expansion. It is showed that a renormalization scheme (minimal subtraction) clearly defines the operator product expansion. In the quantum electrodynamics, it is shown that BRS symmetry can simplify the renormalization process. Composite operators are the renormalized and renormalized stress-energy tensor is formed

  3. Field theory of strings

    International Nuclear Information System (INIS)

    Ramond, P.

    1987-01-01

    We review the construction of the free equations of motion for open and closed strings in 26 dimensions, using the methods of the Florida Group. Differing from previous treatments, we argue that the constraint L 0 -anti L 0 =0 should not be imposed on all the fields of the closed string in the gauge invariant formalism; we show that it can be incorporated in the gauge invariant formalism at the price of being unable to extract the equations of motion from a Langrangian. We then describe our purely algebraic method to introduce interactions, which works equally well for open and closed strings. Quartic interactions are absent except in the Physical Gauge. Finally, we speculate on the role of the measure of the open string path functional. (orig.)

  4. Field theory of strings

    International Nuclear Information System (INIS)

    Ramond, P.

    1986-01-01

    We review the construction of the free equations of motion for open and closed strings in 26 dimensions, using the methods of the Florida Group. Differing from previous treatments, we argue that the constraint L 0 - L 0 -bar = 0 should not be imposed on all the fields of the closed string in the gauge invariant formalism: we show that it can be incorporated in the invariant formalism at the price of being unable to extract the equations of motion from a Lagrangian. We then describe our purely algebraic method to introduce interactions, which works equally well for open and closed strings. Quartic interactions are absent except in the Physical Gauge. Finally, we speculate on the role of the measure of the open string path functional. 20 refs

  5. Classical field theory with fermions

    International Nuclear Information System (INIS)

    Borsanyi, Sz.; Hindmarsh, M.

    2009-01-01

    Classical field theory simulations have been essential for our understanding of non-equilibrium phenomena in particle physics. In this talk we discuss the possible extension of the bosonic classical field theory simulations to include fermions. In principle we use the inhomogeneous mean field approximation as introduced by Aarts and Smit. But in practice we turn from their deterministic technique to a stochastic approach. We represent the fermion field as an ensemble of pairs of spinor fields, dubbed male and female. These c-number fields solve the classical Dirac equation. Our improved algorithm enables the extension of the originally 1+1 dimensional analyses and is suitable for large-scale inhomogeneous settings, like defect networks.

  6. Dynamics of magnetic fields in Maxwell, Yang-Mills and Chern-Simons theories on the torus

    International Nuclear Information System (INIS)

    Burgess, M.; McLachlan, A.; Toms, D.J.

    1992-01-01

    The problem of uniform magnetic fields passing perpendicularly through a 2-torus, Abelian and Non-Abelian, is considered. Focus is on dynamical effects of non-integrable phases on the torus at non zero B and from magnetic fields themselves in the vacuum. The spectrum is computed and is shown to be always independent of the non-integrable phases on the torus. It is concluded that a Chern-Simons term will always be induced by radiative corrections to fermions on the torus when B ≠ 0. The special case of an electromagnetically uncharged anyon gas in noted and shown to be a system whose spectrum can depend on the non-integrable phases in the two torus directions, subject to a consistency requirement. In three and four dimensions, dynamical symmetry breaking of non-Abelian fields and associated condensate formation is possible by radiative corrections. The classification on non-Abelian magnetic fields in terms of ''flux integers'' is discussed, and a method for obtaining such integers for an arbitrary gauge algebra is presented. This provides a rigorous generalisation of Hooft's su (2) classification. 72 refs., 5 figs

  7. The Gribov Legacy, Gauge Theories and the Physical S-Matrix

    Science.gov (United States)

    White, Alan R.

    Reggeon unitarity and non-Abelian gauge field copies are focused on as two Gribov discoveries that, it is suggested, may ultimately be seen as the most significant and that could, in the far distant future, form the cornerstones of his legacy. The crucial role played by the Gribov ambiguity in the construction of gauge theory bound-state amplitudes via reggeon unitarity is described. It is suggested that the existence of a physical, unitary, S-Matrix in a gauge theory is a major requirement that could even determine the theory.

  8. On the gauge dependence of spontaneous symmetry breaking in gauge theories

    International Nuclear Information System (INIS)

    Nielsen, N.K.

    1975-01-01

    The Ward-Takahashi identities for scalar electrodynamics in Fermi gauges are shown to imply a homogeneous first-order partial differential equation for the effective potential involving only the gauge parameter and the external scalar field. Spontaneous symmetry breaking is consequently a gauge-invariant phenomenon. Also observable quantities, including masses, physical coupling constants, and S-matrix elements, of a theory with spontaneous symmetry breaking are found to be invariant, if a change in the gauge parameter is accompanied by a suitable change in the ground-state expectation value of the scalar field. The generalization to a non-Abelian gauge theory is briefly indicated. (Auth.)

  9. Electromagnetic field theories for engineering

    CERN Document Server

    Salam, Md Abdus

    2014-01-01

    A four year Electrical and Electronic engineering curriculum normally contains two modules of electromagnetic field theories during the first two years. However, some curricula do not have enough slots to accommodate the two modules. This book, Electromagnetic Field Theories, is designed for Electrical and Electronic engineering undergraduate students to provide fundamental knowledge of electromagnetic fields and waves in a structured manner. A comprehensive fundamental knowledge of electric and magnetic fields is required to understand the working principles of generators, motors and transformers. This knowledge is also necessary to analyze transmission lines, substations, insulator flashover mechanism, transient phenomena, etc. Recently, academics and researches are working for sending electrical power to a remote area by designing a suitable antenna. In this case, the knowledge of electromagnetic fields is considered as important tool.

  10. Generalized field theory of gravitation

    International Nuclear Information System (INIS)

    Yilmaz, H.

    1976-01-01

    It is shown that if, on empirical grounds, one rules out the existence of cosmic fields of Dicke-Brans (scalar) and Will Nordvedt (vector, tensor) type, then the most general experimentally viable and theoretically reasonable theory of gravitation seems to be a LAMBDA-dependent generalization of Einstein and Yilmez theories, which reduces to the former for LAMBDA=0 and to the latter for LAMBDA=1

  11. The Energy-Momentum Tensor(s) in Classical Gauge Theories

    OpenAIRE

    Blaschke, Daniel N.; Gieres, Francois; Reboud, Meril; Schweda, Manfred

    2016-01-01

    We give an introduction to, and review of, the energy–momentum tensors in classical gauge field theories in Minkowski space, and to some extent also in curved space–time. For the canonical energy–momentum tensor of non-Abelian gauge fields and of matter fields coupled to such fields, we present a new and simple improvement procedure based on gauge invariance for constructing a gauge invariant, symmetric energy–momentum tensor. The relationship with the Einstein–Hilbert tensor following from t...

  12. Renormalization of topological field theory

    International Nuclear Information System (INIS)

    Birmingham, D.; Rakowski, M.; Thompson, G.

    1988-11-01

    One loop corrections to topological field theory in three and four dimensions are presented. By regularizing determinants, we compute the effective action and β-function in four dimensional topological Yang-Mills theory and find that the BRST symmetry is preserved. Moreover, the minima of the effective action still correspond to instanton configurations. In three dimensions, an analysis of the Chern-Simons theory shows that the topological nature of the theory is also preserved to this order. In addition, we find that this theory possesses an extra supersymmetry when quantized in the Landau gauge. Using dimensional regularization, we then study the Ward identities of the extended BRST symmetry in the three dimensional topological Yang-Mills-Higgs model. (author). 22 refs

  13. Gauge and supergauge field theories

    International Nuclear Information System (INIS)

    Slavnov, A.

    1977-01-01

    The most actual problems concerning gauge fields are reviwed. Theoretical investigations conducted since as early as 1954 are enclosed. Present status of gauge theories is summarized, including intermediate vector mesons, heavy leptons, weak interactions of hadrons, V-A structure, universal interaction, infrared divergences in perturbation theory, particle-like solutions in gauge theories, spontaneous symmetry breaking. Special emphasis is placed on strong interactions, or more precisely, on the alleged unobservability of ''color'' objects (quark confinement). Problems dealing with the supersymmetric theories invariant under gauge transformations and spontaneous breaking of supersymmetry are also discussed. Gauge theories are concluded to provide self-consistent apparatus for weak and electromagnetic interactions. As to strong interactions such models are still to be discovered

  14. Embedded mean-field theory.

    Science.gov (United States)

    Fornace, Mark E; Lee, Joonho; Miyamoto, Kaito; Manby, Frederick R; Miller, Thomas F

    2015-02-10

    We introduce embedded mean-field theory (EMFT), an approach that flexibly allows for the embedding of one mean-field theory in another without the need to specify or fix the number of particles in each subsystem. EMFT is simple, is well-defined without recourse to parameters, and inherits the simple gradient theory of the parent mean-field theories. In this paper, we report extensive benchmarking of EMFT for the case where the subsystems are treated using different levels of Kohn-Sham theory, using PBE or B3LYP/6-31G* in the high-level subsystem and LDA/STO-3G in the low-level subsystem; we also investigate different levels of density fitting in the two subsystems. Over a wide range of chemical problems, we find EMFT to perform accurately and stably, smoothly converging to the high-level of theory as the active subsystem becomes larger. In most cases, the performance is at least as good as that of ONIOM, but the advantages of EMFT are highlighted by examples that involve partitions across multiple bonds or through aromatic systems and by examples that involve more complicated electronic structure. EMFT is simple and parameter free, and based on the tests provided here, it offers an appealing new approach to a multiscale electronic structure.

  15. Geometry of lattice field theory

    International Nuclear Information System (INIS)

    Honan, T.J.

    1986-01-01

    Using some tools of algebraic topology, a general formalism for lattice field theory is presented. The lattice is taken to be a simplicial complex that is also a manifold and is referred to as a simplicial manifold. The fields on this lattice are cochains, that are called lattice forms to emphasize the connections with differential forms in the continuum. This connection provides a new bridge between lattice and continuum field theory. A metric can be put onto this simplicial manifold by assigning lengths to every link or I-simplex of the lattice. Regge calculus is a way of defining general relativity on this lattice. A geometric discussion of Regge calculus is presented. The Regge action, which is a discrete form of the Hilbert action, is derived from the Hilbert action using distribution valued forms. This is a new derivation that emphasizes the underlying geometry. Kramers-Wannier duality in statistical mechanics is discussed in this general setting. Nonlinear field theories, which include gauge theories and nonlinear sigma models are discussed in the continuum and then are put onto a lattice. The main new result here is the generalization to curved spacetime, which consists of making the theory compatible with Regge calculus

  16. Bosonic colored group field theory

    Energy Technology Data Exchange (ETDEWEB)

    Ben Geloun, Joseph [Universite Paris XI, Laboratoire de Physique Theorique, Orsay Cedex (France); University of Abomey-Calavi, Cotonou (BJ). International Chair in Mathematical Physics and Applications (ICMPA-UNESCO Chair); Universite Cheikh Anta Diop, Departement de Mathematiques et Informatique, Faculte des Sciences et Techniques, Dakar (Senegal); Magnen, Jacques [Ecole Polytechnique, Centre de Physique Theorique, Palaiseau Cedex (France); Rivasseau, Vincent [Universite Paris XI, Laboratoire de Physique Theorique, Orsay Cedex (France)

    2010-12-15

    Bosonic colored group field theory is considered. Focusing first on dimension four, namely the colored Ooguri group field model, the main properties of Feynman graphs are studied. This leads to a theorem on optimal perturbative bounds of Feynman amplitudes in the ''ultraspin'' (large spin) limit. The results are generalized in any dimension. Finally, integrating out two colors we write a new representation, which could be useful for the constructive analysis of this type of models. (orig.)

  17. Gravitation and bilocal field theory

    International Nuclear Information System (INIS)

    Vollendorf, F.

    1975-01-01

    The starting point is the conjecture that a field theory of elementary particles can be constructed only in a bilocal version. Thus the 4-dimensional space time has to be replaced by the 8-dimensional manifold R 8 of all ordered pairs of space time events. With special reference to the Schwarzschild metric it is shown that the embedding of the time space into the manifold R 8 yields a description of the gravitational field. (orig.) [de

  18. Entanglement from topology in Chern-Simons theory

    Science.gov (United States)

    Salton, Grant; Swingle, Brian; Walter, Michael

    2017-05-01

    The way in which geometry encodes entanglement is a topic of much recent interest in quantum many-body physics and the AdS/CFT duality. This relation is particularly pronounced in the case of topological quantum field theories, where topology alone determines the quantum states of the theory. In this work, we study the set of quantum states that can be prepared by the Euclidean path integral in three-dimensional Chern-Simons theory. Specifically, we consider arbitrary three-manifolds with a fixed number of torus boundaries in both Abelian U (1 ) and non-Abelian S O (3 ) Chern-Simons theory. For the Abelian theory, we find that the states that can be prepared coincide precisely with the set of stabilizer states from quantum information theory. This constrains the multipartite entanglement present in this theory, but it also reveals that stabilizer states can be described by topology. In particular, we find an explicit expression for the entanglement entropy of a many-torus subsystem using only a single replica, as well as a concrete formula for the number of GHZ states that can be distilled from a tripartite state prepared through path integration. For the non-Abelian theory, we find a notion of "state universality," namely that any state can be prepared to an arbitrarily good approximation. The manifolds we consider can also be viewed as toy models of multiboundary wormholes in AdS/CFT.

  19. Computers for lattice field theories

    International Nuclear Information System (INIS)

    Iwasaki, Y.

    1994-01-01

    Parallel computers dedicated to lattice field theories are reviewed with emphasis on the three recent projects, the Teraflops project in the US, the CP-PACS project in Japan and the 0.5-Teraflops project in the US. Some new commercial parallel computers are also discussed. Recent development of semiconductor technologies is briefly surveyed in relation to possible approaches toward Teraflops computers. (orig.)

  20. Dimensional analysis in field theory

    International Nuclear Information System (INIS)

    Stevenson, P.M.

    1981-01-01

    Dimensional Transmutation (the breakdown of scale invariance in field theories) is reconciled with the commonsense notions of Dimensional Analysis. This makes possible a discussion of the meaning of the Renormalisation Group equations, completely divorced from the technicalities of renormalisation. As illustrations, I describe some very farmiliar QCD results in these terms

  1. Electron-electron scattering in the Weinberg-Salam theory

    International Nuclear Information System (INIS)

    Hirashima, Hideharu

    1988-01-01

    The Weinberg theory is generally believed to have been established in recent years. At distances smaller than 10 -16 cm, the strength of weak interactions becomes almost equal to that of the electromagnetic interactions. The grand unified theories proposed so far are based on the idea that the coupling constants for the Abelian U(1) field, the non-Abelian SU(2) field and the non-Abelian SU(3) color field depend on momentum transfer, or distance. At distances smaller than 10 -29 cm, weak electromagnetic and strong interactions are assumed to become almost the same strength. The question here is whether nature has no new features in the vast range from 10 -16 cm (10 2 GeV) to 10 -29 cm (10 15 GeV) and whether the substructure of quark or lepton can be expected to be revealed at the next accelerator energy region. The Weinberger-Salam theory may lose its validity even in near future experiments. In any case, it must be overhauled from various aspects. From this point of view, by using the Weinberger-Salam theory, calculation of the differential cross section for elastic electron-electron scattering is re-examined to make clear the difference with the results of QED. In addition, as an example of experiments which could investigate the Weinberger-Salam theory more in detail, a short account is given of the elastic scattering of polarized electrons from a polarized electron target. (Nogami, K.)

  2. The Gribov problem in presence of background field for SU(2 Yang–Mills theory

    Directory of Open Access Journals (Sweden)

    Fabrizio Canfora

    2016-12-01

    Full Text Available The Gribov problem in the presence of a background field is analyzed: in particular, we study the Gribov copies equation in the Landau–De Witt gauge as well as the semi-classical Gribov gap equation. As background field, we choose the simplest non-trivial one which corresponds to a constant gauge potential with non-vanishing component along the Euclidean time direction. This kind of constant non-Abelian background fields is very relevant in relation with (the computation of the Polyakov loop but it also appears when one considers the non-Abelian Schwinger effect. We show that the Gribov copies equation is affected directly by the presence of the background field, constructing an explicit example. The analysis of the Gribov gap equation shows that the larger the background field, the smaller the Gribov mass parameter. These results strongly suggest that the relevance of the Gribov copies (from the path integral point of view decreases as the size of the background field increases.

  3. Growing up with field theory

    International Nuclear Information System (INIS)

    Vajskopf, V.F.

    1982-01-01

    The article deals with the history of the development of quantum electrodynamics since the date of publishing the work by P.A.M. Dirac ''The Quantum Theory of the Emission and Absorption of Radiation''. Classic ''before-Dirac'' electrodynamics related with the names of Maxwell, Lorenz, Hertz, is outlined. Work of Bohr and Rosenfeld is shown to clarify the physical sense of quantized field and to reveal the existence of uncertainties between the strengths of different fields. The article points to the significance of the article ''Quantum theory of radiation'' by E. Fermi which clearly describes the Dirac theory of radiation, relativistic wave equation and fundamentals of quantum electrodynamics. Shown is work on elimination of troubles related with the existence of states with negative kinetic energy or with negative mass. Hypothesis on the Dirac filled-in vacuum led to understanding of the existence of antiparticles and two unknown till then fundamental processes - pair production and annihilation. Ways of fighting against the infinite quantities in quantum electrodynamics are considered. Renormalization of the theory overcame all the infinities and gave a pattern for calculation of any processes of electron interactions with electromagnetic field to any desired accuracy

  4. Exceptional field theory: SL(5)

    International Nuclear Information System (INIS)

    Musaev, Edvard T.

    2016-01-01

    In this work the exceptional field theory formulation of supergravity with SL(5) gauge group is considered. This group appears as a U-duality group of D=7 maximal supergravity. In the formalism presented the hidden global duality group is promoted into a gauge group of a theory in dimensions 7+number of extended directions. This work is a continuation of the series of works for E 8,7,6 ,SO(5,5) and SL(3)×SL(2) duality groups.

  5. Perturbative coherence in field theory

    International Nuclear Information System (INIS)

    Aldrovandi, R.; Kraenkel, R.A.

    1987-01-01

    A general condition for coherent quantization by perturbative methods is given, because the basic field equations of a fild theory are not always derivable from a Lagrangian. It's seen that non-lagrangian models way have well defined vertices, provided they satisfy what they call the 'coherence condition', which is less stringent than the condition for the existence of a Lagrangian. They note that Lagrangian theories are perturbatively coherent, in the sense that they have well defined vertices, and that they satisfy automatically that condition. (G.D.F.) [pt

  6. Einstein's theory of unified fields

    CERN Document Server

    Tonnelat, Marie Antoinette

    2014-01-01

    First published in1966, here is presented a comprehensive overview of one of the most elusive scientific speculations by the pre-eminent genius of the 20th century. The theory is viewed by some scientists with deep suspicion, by others with optimism, but all agree that it represents an extreme challenge. As the author herself affirms, this work is not intended to be a complete treatise or 'didactic exposition' of the theory of unified fields, but rather a tool for further study, both by students and professional physicists. Dealing with all the major areas of research whic

  7. A course in field theory

    CERN Document Server

    Baal, Pierre Van

    2014-01-01

    ""… a pleasant novelty that manages the impossible: a full course in field theory from a derivation of the Dirac equation to the standard electroweak theory in less than 200 pages. Moreover, the final chapter consists of a careful selection of assorted problems, which are original and either anticipate or detail some of the topics discussed in the bulk of the chapters. Instead of building a treatise out of a collection of lecture notes, the author took the complementary approach and constructed a course out of a number of well-known and classic treatises. The result is fresh and useful. … the

  8. Introduction to quantum field theory

    CERN Document Server

    Chang, Shau-Jin

    1990-01-01

    This book presents in a short volume the basics of quantum field theory and many body physics. The first part introduces the perturbative techniques without sophisticated apparatus and applies them to numerous problems including quantum electrodynamics (renormalization), Fermi and Bose gases, the Brueckner theory of nuclear system, liquid Helium and classical systems with noise. The material is clear, illustrative and the important points are stressed to help the reader get the understanding of what is crucial without overwhelming him with unnecessary detours or comments. The material in the s

  9. Entropic destruction of heavy quarkonium in non-Abelian plasma from holography

    Science.gov (United States)

    Hashimoto, Koji; Kharzeev, Dmitri E.

    2014-12-01

    Lattice QCD indicates a large amount of entropy associated with the heavy quark-antiquark pair immersed in the quark-gluon plasma. This entropy grows as a function of the interquark distance giving rise to an entropic force that can be very effective in dissociating the bound quarkonium states. In addition, the lattice data show a very sharp peak in the heavy quark-antiquark entropy at the deconfinement transition. Since the quark-gluon plasma around the deconfinement transition is strongly coupled, we employ the holographic correspondence to study the entropy associated with the heavy quark-antiquark pair in two theories: (i) N =4 supersymmetric Yang-Mills and (ii) a confining Yang-Mills theory obtained by compactification on a Kaluza-Klein circle. In both cases we find the entropy growing with the interquark distance and evaluate the effect of the corresponding entropic forces. In the case (ii), we find a sharp peak in the entropy near the deconfinement transition, in agreement with the lattice QCD results. This peak in our holographic description arises because the heavy quark pair acts as an eyewitness to the black hole formation in the bulk—the process that describes the deconfinement transition. In terms of the boundary theory, this entropy likely emerges from the entanglement of a "long string" connecting the quark and antiquark with the rest of the system.

  10. "Wormhole" geometry for entrapping topologically-protected qubits in non-Abelian quantum Hall states and probing them with voltage and noise measurements

    OpenAIRE

    Hou, Chang-Yu; Chamon, Claudio

    2006-01-01

    We study a tunneling geometry defined by a single point-contact constriction that brings to close vicinity two points sitting at the same edge of a quantum Hall liquid, shortening the trip between the otherwise spatially separated points along the normal chiral edge path. This ``wormhole''-like geometry allows for entrapping bulk quasiparticles between the edge path and the tunnel junction, possibly realizing a topologically protected qubit if the quasiparticles have non-Abelian statistics. W...

  11. Variational methods for field theories

    International Nuclear Information System (INIS)

    Ben-Menahem, S.

    1986-09-01

    Four field theory models are studied: Periodic Quantum Electrodynamics (PQED) in (2 + 1) dimensions, free scalar field theory in (1 + 1) dimensions, the Quantum XY model in (1 + 1) dimensions, and the (1 + 1) dimensional Ising model in a transverse magnetic field. The last three parts deal exclusively with variational methods; the PQED part involves mainly the path-integral approach. The PQED calculation results in a better understanding of the connection between electric confinement through monopole screening, and confinement through tunneling between degenerate vacua. This includes a better quantitative agreement for the string tensions in the two approaches. Free field theory is used as a laboratory for a new variational blocking-truncation approximation, in which the high-frequency modes in a block are truncated to wave functions that depend on the slower background modes (Boron-Oppenheimer approximation). This ''adiabatic truncation'' method gives very accurate results for ground-state energy density and correlation functions. Various adiabatic schemes, with one variable kept per site and then two variables per site, are used. For the XY model, several trial wave functions for the ground state are explored, with an emphasis on the periodic Gaussian. A connection is established with the vortex Coulomb gas of the Euclidean path integral approach. The approximations used are taken from the realms of statistical mechanics (mean field approximation, transfer-matrix methods) and of quantum mechanics (iterative blocking schemes). In developing blocking schemes based on continuous variables, problems due to the periodicity of the model were solved. Our results exhibit an order-disorder phase transition. The transfer-matrix method is used to find a good (non-blocking) trial ground state for the Ising model in a transverse magnetic field in (1 + 1) dimensions

  12. Variational methods for field theories

    Energy Technology Data Exchange (ETDEWEB)

    Ben-Menahem, S.

    1986-09-01

    Four field theory models are studied: Periodic Quantum Electrodynamics (PQED) in (2 + 1) dimensions, free scalar field theory in (1 + 1) dimensions, the Quantum XY model in (1 + 1) dimensions, and the (1 + 1) dimensional Ising model in a transverse magnetic field. The last three parts deal exclusively with variational methods; the PQED part involves mainly the path-integral approach. The PQED calculation results in a better understanding of the connection between electric confinement through monopole screening, and confinement through tunneling between degenerate vacua. This includes a better quantitative agreement for the string tensions in the two approaches. Free field theory is used as a laboratory for a new variational blocking-truncation approximation, in which the high-frequency modes in a block are truncated to wave functions that depend on the slower background modes (Boron-Oppenheimer approximation). This ''adiabatic truncation'' method gives very accurate results for ground-state energy density and correlation functions. Various adiabatic schemes, with one variable kept per site and then two variables per site, are used. For the XY model, several trial wave functions for the ground state are explored, with an emphasis on the periodic Gaussian. A connection is established with the vortex Coulomb gas of the Euclidean path integral approach. The approximations used are taken from the realms of statistical mechanics (mean field approximation, transfer-matrix methods) and of quantum mechanics (iterative blocking schemes). In developing blocking schemes based on continuous variables, problems due to the periodicity of the model were solved. Our results exhibit an order-disorder phase transition. The transfer-matrix method is used to find a good (non-blocking) trial ground state for the Ising model in a transverse magnetic field in (1 + 1) dimensions.

  13. Theory of field reversed configurations

    International Nuclear Information System (INIS)

    Steinhauer, L.C.

    1990-01-01

    This final report surveys the results of work conducted on the theory of field reversed configurations. This project has spanned ten years, beginning in early 1980. During this period, Spectra Technology was one of the leading contributors to the advances in understanding FRC. The report is organized into technical topic areas, FRC formation, equilibrium, stability, and transport. Included as an appendix are papers published in archival journals that were generated in the course of this report. 33 refs

  14. Geometrodynamics of gauge fields on the geometry of Yang-Mills and gravitational gauge theories

    CERN Document Server

    Mielke, Eckehard W

    2016-01-01

    This monograph aims to provide a unified, geometrical foundation of gauge theories of elementary particle physics. The underlying geometrical structure is unfolded in a coordinate-free manner via the modern mathematical notions of fibre bundles and exterior forms. Topics such as the dynamics of Yang-Mills theories, instanton solutions and topological invariants are included. By transferring these concepts to local space-time symmetries, generalizations of Einstein's theory of gravity arise in a Riemann-Cartan space with curvature and torsion. It provides the framework in which the (broken) Poincaré gauge theory, the Rainich geometrization of the Einstein-Maxwell system, and higher-dimensional, non-abelian Kaluza-Klein theories are developed. Since the discovery of the Higgs boson, concepts of spontaneous symmetry breaking in gravity have come again into focus, and, in this revised edition, these will be exposed in geometric terms. Quantizing gravity remains an open issue: formulating it as a de Sitter t...

  15. Twenty five years of fundamental theory

    International Nuclear Information System (INIS)

    Bell, J.S.

    1980-01-01

    In reviewing the last twenty five years in fundamental physics theory it is stated that there has been no revolution in this field. In the absence of gravitation, Lorentz invariance remains a requirement on fundamental laws. Einstein's theory of gravitation inspires increasing conviction on the astronomical scale. Quantum theory remains the framework for all serious effort in microphysics, and quantum electrodynamics remains the model of a fully articulated microphysical theory, completely successful in its domain. However,a number of ideas have appeared, of great theoretical interest and some phenomenological success, which may well contribute to the next decisive step. Recent work on the following topics is mentioned; gravitational radiation, singularites, black body radiation from black holes, gauge and hidden symmetry in quantum electrodynamics, the renormalization of electromagnetic and weak interaction theory, non-Abelian gauge theories, magnetic monopoles as the most striking example of solitons, and supersymmetry. (UK)

  16. On incompleteness of classical field theory

    OpenAIRE

    Sardanashvily, G.

    2009-01-01

    Classical field theory is adequately formulated as Lagrangian theory on fibre bundles and graded manifolds. One however observes that non-trivial higher stage Noether identities and gauge symmetries of a generic reducible degenerate Lagrangian field theory fail to be defined. Therefore, such a field theory can not be quantized.

  17. Non Abelian Sugawara construction and the q-deformed N=2 superconformal algebra

    Energy Technology Data Exchange (ETDEWEB)

    Batista, E.; Gomes, J.F.; Lautenschleguer, I.J.

    1996-03-01

    The construction of a q-deformed N=2 superconformal algebra is proposed in terms of level 1 current of U{sub q}(su(2)) quantum affine Lie algebra and a single real Fermi field. In particular, it suggests the expression for the q-deformed Energy-Momentum tensor in the Sugawara form. Its constituents generate two isomorphic quadratic algebraic structures. The generalization to U{sub q}(su(N+1)) is also proposed. (author). 17 refs.

  18. Introduction to conformal field theory. With applications to string theory

    International Nuclear Information System (INIS)

    Blumenhagen, Ralph; Plauschinn, Erik

    2009-01-01

    Based on class-tested notes, this text offers an introduction to Conformal Field Theory with a special emphasis on computational techniques of relevance for String Theory. It introduces Conformal Field Theory at a basic level, Kac-Moody algebras, one-loop partition functions, Superconformal Field Theories, Gepner Models and Boundary Conformal Field Theory. Eventually, the concept of orientifold constructions is explained in detail for the example of the bosonic string. In providing many detailed CFT calculations, this book is ideal for students and scientists intending to become acquainted with CFT techniques relevant for string theory but also for students and non-specialists from related fields. (orig.)

  19. Braided quantum field theories and their symmetries

    International Nuclear Information System (INIS)

    Sasai, Yuya; Sasakura, Naoki

    2007-01-01

    Braided quantum field theories, proposed by Oeckl, can provide a framework for quantum field theories that possess Hopf algebra symmetries. In quantum field theories, symmetries lead to non-perturbative relations among correlation functions. We study Hopf algebra symmetries and such relations in the context of braided quantum field theories. We give the four algebraic conditions among Hopf algebra symmetries and braided quantum field theories that are required for the relations to hold. As concrete examples, we apply our analysis to the Poincare symmetries of two examples of noncommutative field theories. One is the effective quantum field theory of three-dimensional quantum gravity coupled to spinless particles formulated by Freidel and Livine, and the other is noncommutative field theory on the Moyal plane. We also comment on quantum field theory in κ-Minkowski spacetime. (author)

  20. A relation between approaches to integrability in superconformal Yang-Mills theory

    Energy Technology Data Exchange (ETDEWEB)

    Dolan, Louise E-mail: ldolan@physics.unc.edu; Nappi, Chiara R.; Witten, Edward

    2003-10-01

    We make contact between the infinite-dimensional non-local symmetry of the type IIB superstring on AdS5 x S5 worldsheet theory and a non-abelian infinite-dimensional symmetry algebra for the weakly coupled superconformal gauge theory. We explain why the planar limit of the one-loop dilatation operator is the Hamiltonian of a spin chain, and show that it commutes with the g*2 N = 0 limit of the non-abelian charges. (author)

  1. Inverse bootstrapping conformal field theories

    Science.gov (United States)

    Li, Wenliang

    2018-01-01

    We propose a novel approach to study conformal field theories (CFTs) in general dimensions. In the conformal bootstrap program, one usually searches for consistent CFT data that satisfy crossing symmetry. In the new method, we reverse the logic and interpret manifestly crossing-symmetric functions as generating functions of conformal data. Physical CFTs can be obtained by scanning the space of crossing-symmetric functions. By truncating the fusion rules, we are able to concentrate on the low-lying operators and derive some approximate relations for their conformal data. It turns out that the free scalar theory, the 2d minimal model CFTs, the ϕ 4 Wilson-Fisher CFT, the Lee-Yang CFTs and the Ising CFTs are consistent with the universal relations from the minimal fusion rule ϕ 1 × ϕ 1 = I + ϕ 2 + T , where ϕ 1 , ϕ 2 are scalar operators, I is the identity operator and T is the stress tensor.

  2. Inert two-Higgs-doublet model strongly coupled to a non-Abelian vector resonance

    Science.gov (United States)

    Rojas-Abatte, Felipe; Mora, Maria Luisa; Urbina, Jose; Zerwekh, Alfonso R.

    2017-11-01

    We study the possibility of a dark matter candidate having its origin in an extended Higgs sector which, at least partially, is related to a new strongly interacting sector. More concretely, we consider an i2HDM (i.e., a Type-I two Higgs doublet model supplemented with a Z2 under which the nonstandard scalar doublet is odd) based on the gauge group S U (2 )1×S U (2 )2×U (1 )Y . We assume that one of the scalar doublets and the standard fermion transform nontrivially under S U (2 )1 while the second doublet transforms under S U (2 )2. Our main hypothesis is that standard sector is weakly coupled while the gauge interactions associated to the second group is characterized by a large coupling constant. We explore the consequences of this construction for the phenomenology of the dark matter candidate and we show that the presence of the new vector resonance reduces the relic density saturation region, compared to the usual i2DHM, in the high dark matter mass range. In the collider side, we argue that the mono-Z production is the channel which offers the best chances to manifest the presence of the new vector field. We study the departures from the usual i2HDM predictions and show that the discovery of the heavy vector at the LHC is challenging even in the mono-Z channel since the typical cross sections are of the order of 10-2 fb .

  3. Regularization of quantum field theories

    International Nuclear Information System (INIS)

    Rayski, J.

    1985-01-01

    General idea of regularization and renormalization in quantum field theory is presented. It is postulated that it is possible not to go to infinity with the auxiliary masses of regularization but to attach to them a certain physical meaning, but it is equivalent with a violation of unitarity of the operator of evolution in time. It may be achieved in two different ways: it might be simply assumed that only the direction but not the length of the state vector possesses a physical meaning and that not all possible physical events are predictable. 3 refs., 1 fig. (author)

  4. Topics in low-dimensional field theory

    Energy Technology Data Exchange (ETDEWEB)

    Crescimanno, M.J.

    1991-04-30

    Conformal field theory is a natural tool for understanding two- dimensional critical systems. This work presents results in the lagrangian approach to conformal field theory. The first sections are chiefly about a particular class of field theories called coset constructions and the last part is an exposition of the connection between two-dimensional conformal theory and a three-dimensional gauge theory whose lagrangian is the Chern-Simons density.

  5. Number theory arising from finite fields analytic and probabilistic theory

    CERN Document Server

    Knopfmacher, John

    2001-01-01

    ""Number Theory Arising from Finite Fields: Analytic and Probabilistic Theory"" offers a discussion of the advances and developments in the field of number theory arising from finite fields. It emphasizes mean-value theorems of multiplicative functions, the theory of additive formulations, and the normal distribution of values from additive functions. The work explores calculations from classical stages to emerging discoveries in alternative abstract prime number theorems.

  6. Vertex operator algebras and conformal field theory

    International Nuclear Information System (INIS)

    Huang, Y.Z.

    1992-01-01

    This paper discusses conformal field theory, an important physical theory, describing both two-dimensional critical phenomena in condensed matter physics and classical motions of strings in string theory. The study of conformal field theory will deepen the understanding of these theories and will help to understand string theory conceptually. Besides its importance in physics, the beautiful and rich mathematical structure of conformal field theory has interested many mathematicians. New relations between different branches of mathematics, such as representations of infinite-dimensional Lie algebras and Lie groups, Riemann surfaces and algebraic curves, the Monster sporadic group, modular functions and modular forms, elliptic genera and elliptic cohomology, Calabi-Yau manifolds, tensor categories, and knot theory, are revealed in the study of conformal field theory. It is therefore believed that the study of the mathematics involved in conformal field theory will ultimately lead to new mathematical structures which would be important to both mathematics and physics

  7. Quantum Field Theory in (0 + 1) Dimensions

    Science.gov (United States)

    Boozer, A. D.

    2007-01-01

    We show that many of the key ideas of quantum field theory can be illustrated simply and straightforwardly by using toy models in (0 + 1) dimensions. Because quantum field theory in (0 + 1) dimensions is equivalent to quantum mechanics, these models allow us to use techniques from quantum mechanics to gain insight into quantum field theory. In…

  8. Study of the correspondence between dual thermal transformations and gauge fields

    International Nuclear Information System (INIS)

    Civitarese, O.; De Paoli, A.L.; Rocca, M.C.

    1995-01-01

    The correspondence between dual thermal transformations of the thermo field dynamics (TFD) and gauge fields is studied both for abelian and non-abelian theories. It is found that the action for the TFD representation of a Dirac's lagrangian remains invariant under local transformations in k-space. The conserved charge coincides with the TFD vacuum-generator G introduced by Takahashi and Umezawa. The relationship between the rules of the TFD and the principle of gauge invariance in a thermal subspace is discussed in the context of a thermal symmetry breaking. ((orig.))

  9. Gaussian processes and constructive scalar field theory

    International Nuclear Information System (INIS)

    Benfatto, G.; Nicolo, F.

    1981-01-01

    The last years have seen a very deep progress of constructive euclidean field theory, with many implications in the area of the random fields theory. The authors discuss an approach to super-renormalizable scalar field theories, which puts in particular evidence the connections with the theory of the Gaussian processes associated to the elliptic operators. The paper consists of two parts. Part I treats some problems in the theory of Gaussian processes which arise in the approach to the PHI 3 4 theory. Part II is devoted to the discussion of the ultraviolet stability in the PHI 3 4 theory. (Auth.)

  10. Effective Field Theory on Manifolds with Boundary

    Science.gov (United States)

    Albert, Benjamin I.

    In the monograph Renormalization and Effective Field Theory, Costello made two major advances in rigorous quantum field theory. Firstly, he gave an inductive position space renormalization procedure for constructing an effective field theory that is based on heat kernel regularization of the propagator. Secondly, he gave a rigorous formulation of quantum gauge theory within effective field theory that makes use of the BV formalism. In this work, we extend Costello's renormalization procedure to a class of manifolds with boundary and make preliminary steps towards extending his formulation of gauge theory to manifolds with boundary. In addition, we reorganize the presentation of the preexisting material, filling in details and strengthening the results.

  11. Light-induced gauge fields for ultracold atoms.

    Science.gov (United States)

    Goldman, N; Juzeliūnas, G; Öhberg, P; Spielman, I B

    2014-12-01

    Gauge fields are central in our modern understanding of physics at all scales. At the highest energy scales known, the microscopic universe is governed by particles interacting with each other through the exchange of gauge bosons. At the largest length scales, our Universe is ruled by gravity, whose gauge structure suggests the existence of a particle-the graviton-that mediates the gravitational force. At the mesoscopic scale, solid-state systems are subjected to gauge fields of different nature: materials can be immersed in external electromagnetic fields, but they can also feature emerging gauge fields in their low-energy description. In this review, we focus on another kind of gauge field: those engineered in systems of ultracold neutral atoms. In these setups, atoms are suitably coupled to laser fields that generate effective gauge potentials in their description. Neutral atoms 'feeling' laser-induced gauge potentials can potentially mimic the behavior of an electron gas subjected to a magnetic field, but also, the interaction of elementary particles with non-Abelian gauge fields. Here, we review different realized and proposed techniques for creating gauge potentials-both Abelian and non-Abelian-in atomic systems and discuss their implication in the context of quantum simulation. While most of these setups concern the realization of background and classical gauge potentials, we conclude with more exotic proposals where these synthetic fields might be made dynamical, in view of simulating interacting gauge theories with cold atoms.

  12. A superstring field theory for supergravity

    Science.gov (United States)

    Reid-Edwards, R. A.; Riccombeni, D. A.

    2017-09-01

    A covariant closed superstring field theory, equivalent to classical tendimensional Type II supergravity, is presented. The defining conformal field theory is the ambitwistor string worldsheet theory of Mason and Skinner. This theory is known to reproduce the scattering amplitudes of Cachazo, He and Yuan in which the scattering equations play an important role and the string field theory naturally incorporates these results. We investigate the operator formalism description of the ambitwsitor string and propose an action for the string field theory of the bosonic and supersymmetric theories. The correct linearised gauge symmetries and spacetime actions are explicitly reproduced and evidence is given that the action is correct to all orders. The focus is on the NeveuSchwarz sector and the explicit description of tree level perturbation theory about flat spacetime. Application of the string field theory to general supergravity backgrounds and the inclusion of the Ramond sector are briefly discussed.

  13. The universal C*-algebra of the electromagnetic field II. Topological charges and spacelike linear fields

    Science.gov (United States)

    Buchholz, Detlev; Ciolli, Fabio; Ruzzi, Giuseppe; Vasselli, Ezio

    2017-02-01

    Conditions for the appearance of topological charges are studied in the framework of the universal C*-algebra of the electromagnetic field, which is represented in any theory describing electromagnetism. It is shown that non-trivial topological charges, described by pairs of fields localised in certain topologically non-trivial spacelike separated regions, can appear in regular representations of the algebra only if the fields depend non-linearly on the mollifying test functions. On the other hand, examples of regular vacuum representations with non-trivial topological charges are constructed, where the underlying field still satisfies a weakened form of "spacelike linearity". Such representations also appear in the presence of electric currents. The status of topological charges in theories with several types of electromagnetic fields, which appear in the short distance (scaling) limit of asymptotically free non-abelian gauge theories, is also briefly discussed.

  14. N=1 field theory duality from M theory

    International Nuclear Information System (INIS)

    Schmaltz, M.; Sundrum, R.

    1998-01-01

    We investigate Seiberg close-quote s N=1 field theory duality for four-dimensional supersymmetric QCD with the M-theory 5-brane. We find that the M-theory configuration for the magnetic dual theory arises via a smooth deformation of the M-theory configuration for the electric theory. The creation of Dirichlet 4-branes as Neveu-Schwarz 5-branes are passed through each other in type IIA string theory is given an elegant derivation from M theory. copyright 1998 The American Physical Society

  15. Quantum Field Theory A Modern Perspective

    CERN Document Server

    Parameswaran Nair, V

    2005-01-01

    Quantum field theory, which started with Paul Dirac’s work shortly after the discovery of quantum mechanics, has produced an impressive and important array of results. Quantum electrodynamics, with its extremely accurate and well-tested predictions, and the standard model of electroweak and chromodynamic (nuclear) forces are examples of successful theories. Field theory has also been applied to a variety of phenomena in condensed matter physics, including superconductivity, superfluidity and the quantum Hall effect. The concept of the renormalization group has given us a new perspective on field theory in general and on critical phenomena in particular. At this stage, a strong case can be made that quantum field theory is the mathematical and intellectual framework for describing and understanding all physical phenomena, except possibly for a quantum theory of gravity. Quantum Field Theory: A Modern Perspective presents Professor Nair’s view of certain topics in field theory loosely knit together as it gr...

  16. On Killing tensors and cubic vertices in higher-spin gauge theories

    International Nuclear Information System (INIS)

    Bekaert, X.; Boulanger, N.; Leclercq, S.; Cnockaert, S.

    2006-01-01

    The problem of determining all consistent non-Abelian local interactions is reviewed in flat space-time. The antifield-BRST formulation of the free theory is an efficient tool to address this problem. Firstly, it allows to compute all on-shell local Killing tensor fields, which are important because of their deep relationship with higher-spin algebras. Secondly, under the sole assumptions of locality and Poincare invariance, all non-trivial consistent deformations of a sum of spin-three quadratic actions deforming the Abelian gauge algebra were determined. They are compared with lower-spin cases. (Abstract Copyright [2006], Wiley Periodicals, Inc.)

  17. Black holes in su(N) Einstein-Yang-Mills theory: hair, fur and superconducting horizons

    Energy Technology Data Exchange (ETDEWEB)

    Winstanley, Elizabeth [School of Mathematics and Statistics, University of Sheffield (United Kingdom)

    2012-07-01

    Black hole solutions of general relativity coupled to an su(N) Yang-Mills gauge field have been studied for over 20 years. In this talk we focus on black holes in Einstein-Yang-Mills theory in four-dimensional, asymptotically anti-de Sitter space, with a negative cosmological constant. We emphasize three aspects of these black holes: (a) the existence of stable black holes in anti-de Sitter space with abundant Yang-Mills hair; (b) how these hairy black holes may be characterized by non-Abelian charges at infinity; (c) planar black holes with superconducting horizons.

  18. Quantum field theory of universe

    International Nuclear Information System (INIS)

    Hosoya, Akio; Morikawa, Masahiro.

    1988-08-01

    As is well-known, the wave function of universe dictated by the Wheeler-DeWitt equation has a difficulty in its probabilistic interpretation. In order to overcome this difficulty, we explore a theoretical possibility of the second quantization of universe, following the same passage historically taken for the Klein-Gordon particles and the Nambu-Goto strings. It turns out that multiple production of universes is an inevitable consequence even if the initial state is nothing. The problematical interpretation of wave function of universe is circumvented by introducing an internal comoving model detector, which is an analogue of the DeWitt-Unruh detector in the quantum field theory in curved space-time. (author)

  19. Octonionic methods in field theory

    International Nuclear Information System (INIS)

    Duendarer, A.R.

    1987-01-01

    Some applications of octonion algebra and octonionic analysis to group theory and higher dimensional field theories are presented. To this end an eight dimensional covariant treatment of the octonion algebra is needed. The existing formulations which are covariant only in seven dimensions are reviewed. In this work the eight dimensional formulation is developed through the introduction of fourth rank tensors f abcd and f' abcd in eight dimensions that generalize the octonionic structure constants. The seven octonion units e α are generalized to an 8-vector e a and two second rank tensors e ab and e' ab . Higher rank tensors associated with e α are also introduced. Chirality and duality properties of the structure tensors, f,f' and the octonionic tensors e a , e ab , etc. are discussed and various new identities relating these quantities are derived. New vector products for two, three and four octonions are introduced and their duality properties with respect to the eight-dimensional Levi-Civita tensor as well as their orthogonality properties are studied

  20. Families and degenerations of conformal field theories

    Energy Technology Data Exchange (ETDEWEB)

    Roggenkamp, D.

    2004-09-01

    In this work, moduli spaces of conformal field theories are investigated. In the first part, moduli spaces corresponding to current-current deformation of conformal field theories are constructed explicitly. For WZW models, they are described in detail, and sigma model realizations of the deformed WZW models are presented. The second part is devoted to the study of boundaries of moduli spaces of conformal field theories. For this purpose a notion of convergence of families of conformal field theories is introduced, which admits certain degenerated conformal field theories to occur as limits. To such a degeneration of conformal field theories, a degeneration of metric spaces together with additional geometric structures can be associated, which give rise to a geometric interpretation. Boundaries of moduli spaces of toroidal conformal field theories, orbifolds thereof and WZW models are analyzed. Furthermore, also the limit of the discrete family of Virasoro minimal models is investigated. (orig.)

  1. Dimensional reduction of Seiberg-Witten monopole equations, N=2 noncommutative supersymmetric field theories and Young diagrams

    International Nuclear Information System (INIS)

    Sako, Akifumi; Suzuki, Toshiya

    2006-01-01

    We investigate the Seiberg-Witten monopole equations on noncommutative (N.C.) R 4 at the large N.C. parameter limit, in terms of the equivariant cohomology. In other words, N=2 supersymmetric U(1) gauge theories with a hypermultiplet on N.C.R 4 are studied. It is known that after topological twisting partition functions of N>1 supersymmetric theories on N.C. R 2D are invariant under the N.C. parameter shift; then the partition functions can be calculated by its dimensional reduction. At the large N.C. parameter limit, the Seiberg-Witten monopole equations are reduced to ADHM equations with the Dirac equation reduced to the 0 dimension. The equations are equivalent to the dimensional reduction of non-Abelian U(N) Seiberg-Witten monopole equations in N→∞. The solutions of the equations are also interpreted as a configuration of a brane antibrane system. The theory has global symmetries under torus actions originated in space rotations and gauge symmetries. We investigate the Seiberg-Witten monopole equations reduced to the 0 dimension and the fixed point equations of the torus actions. We show that the Dirac equation reduced to the 0 dimension is automatically satisfied when the fixed point equations and the ADHM equations are satisfied. Then, we find that the Seiberg-Witten equations reduced to the 0 dimension and fixed point equations of the torus action are equivalent to just the ADHM equations with the fixed point equations. For finite N, it is known that the fixed points of the ADHM data are isolated and are classified by the Young diagrams. We also give a new proof of this statement by solving the ADHM equations and the fixed point equations concretely and by giving graphical interpretations of the field components and these equations

  2. Dimensional reduction of Seiberg-Witten monopole equations, N =2 noncommutative supersymmetric field theories and Young diagrams

    Science.gov (United States)

    Sako, Akifumi; Suzuki, Toshiya

    2006-11-01

    We investigate the Seiberg-Witten monopole equations on noncommutative (N.C.) R4 at the large N.C. parameter limit, in terms of the equivariant cohomology. In other words, N =2 supersymmetric U(1) gauge theories with a hypermultiplet on N.C.R4 are studied. It is known that after topological twisting partition functions of N >1 supersymmetric theories on N.C. R2D are invariant under the N.C. parameter shift; then the partition functions can be calculated by its dimensional reduction. At the large N.C. parameter limit, the Seiberg-Witten monopole equations are reduced to ADHM equations with the Dirac equation reduced to the 0 dimension. The equations are equivalent to the dimensional reduction of non-Abelian U(N) Seiberg-Witten monopole equations in N →∞. The solutions of the equations are also interpreted as a configuration of a brane antibrane system. The theory has global symmetries under torus actions originated in space rotations and gauge symmetries. We investigate the Seiberg-Witten monopole equations reduced to the 0 dimension and the fixed point equations of the torus actions. We show that the Dirac equation reduced to the 0 dimension is automatically satisfied when the fixed point equations and the ADHM equations are satisfied. Then, we find that the Seiberg-Witten equations reduced to the 0 dimension and fixed point equations of the torus action are equivalent to just the ADHM equations with the fixed point equations. For finite N, it is known that the fixed points of the ADHM data are isolated and are classified by the Young diagrams. We also give a new proof of this statement by solving the ADHM equations and the fixed point equations concretely and by giving graphical interpretations of the field components and these equations.

  3. P/NP, and the Quantum Field Computer

    Science.gov (United States)

    Freedman, Michael H.

    1998-01-01

    The central problem is computer science is the conjecture that two complexity classes, P (polynomial time) and NP (nondeterministic polynomial time-roughly those decision problems for which a proposed solution can be checked in polynomial time), are distinct in the standard Turing model of computation: P neq NP. As a generality, we propose that each physical theory supports computational models whose power is limited by the physical theory. It is well known that classical physics supports a multitude of implementation of the Turning machine. Non-Abelian topological quantum field theories exhibit the mathematical features necessary to support a model capable of solving all #P problems, a computationally intractable class, in polynomial time. Specifically, Witten [Witten, E. (1989) Commun. Math. Phys. 121, 351-391] has identified expectation values in a certain SU(2)-field theory with values of the Jones polynomial [Jones, V. (1985) Bull. Am. Math. Soc. 12, 103-111] that are #P-hard [Jaeger, F., Vertigen, D. & Welsh, D. (1990) Math. Proc. Comb. Philos. Soc. 108, 35-53]. This suggests that some physical system whose effective Lagrangian contains a non-Abelian topological term might be manipulated to serve as an analog computer capable of solving NP or even #P-hard problems in polynomial time. Defining such a system and addressing the accuracy issues inherent in preparation and measurement is a major unsolved problem.

  4. BRST field theory of relativistic particles

    International Nuclear Information System (INIS)

    Holten, J.W. van

    1992-01-01

    A generalization of BRST field theory is presented, based on wave operators for the fields constructed out of, but different from the BRST operator. The authors discuss their quantization, gauge fixing and the derivation of propagators. It is shown, that the generalized theories are relevant to relativistic particle theories in the Brink-Di Vecchia-Howe-Polyakov (BDHP) formulation, and argue that the same phenomenon holds in string theories. In particular it is shown, that the naive BRST formulation of the BDHP theory leads to trivial quantum field theories with vanishing correlation functions. (author). 22 refs

  5. Analytical methods applied to the study of lattice gauge and spin theories

    International Nuclear Information System (INIS)

    Moreo, Adriana.

    1985-01-01

    A study of interactions between quarks and gluons is presented. Certain difficulties of the quantum chromodynamics to explain the behaviour of quarks has given origin to the technique of lattice gauge theories. First the phase diagrams of the discrete space-time theories are studied. The analysis of the phase diagrams is made by numerical and analytical methods. The following items were investigated and studied: a) A variational technique was proposed to obtain very accurated values for the ground and first excited state energy of the analyzed theory; b) A mean-field-like approximation for lattice spin models in the link formulation which is a generalization of the mean-plaquette technique was developed; c) A new method to study lattice gauge theories at finite temperature was proposed. For the first time, a non-abelian model was studied with analytical methods; d) An abelian lattice gauge theory with fermionic matter at the strong coupling limit was analyzed. Interesting results applicable to non-abelian gauge theories were obtained. (M.E.L.) [es

  6. Large N Field Theories, String Theory and Gravity

    CERN Document Server

    Aharony, O; Maldacena, J M; Ooguri, H; Oz, Y

    2000-01-01

    We review the holographic correspondence between field theories and string/M theory, focusing on the relation between compactifications of string/M theory on Anti-de Sitter spaces and conformal field theories. We review the background for this correspondence and discuss its motivations and the evidence for its correctness. We describe the main results that have been derived from the correspondence in the regime that the field theory is approximated by classical or semiclassical gravity. We focus on the case of the N=4 supersymmetric gauge theory in four dimensions, but we discuss also field theories in other dimensions, conformal and non-conformal, with or without supersymmetry, and in particular the relation to QCD. We also discuss some implications for black hole physics.

  7. On magnetohydrodynamic gauge field theory

    Science.gov (United States)

    Webb, G. M.; Anco, S. C.

    2017-06-01

    Clebsch potential gauge field theory for magnetohydrodynamics is developed based in part on the theory of Calkin (1963 Can. J. Phys. 41 2241-51). It is shown how the polarization vector {P} in Calkin’s approach naturally arises from the Lagrange multiplier constraint equation for Faraday’s equation for the magnetic induction {B} , or alternatively from the magnetic vector potential form of Faraday’s equation. Gauss’s equation, (divergence of {B} is zero) is incorporated in the variational principle by means of a Lagrange multiplier constraint. Noether’s theorem coupled with the gauge symmetries is used to derive the conservation laws for (a) magnetic helicity, (b) cross helicity, (c) fluid helicity for non-magnetized fluids, and (d) a class of conservation laws associated with curl and divergence equations which applies to Faraday’s equation and Gauss’s equation. The magnetic helicity conservation law is due to a gauge symmetry in MHD and not due to a fluid relabelling symmetry. The analysis is carried out for the general case of a non-barotropic gas in which the gas pressure and internal energy density depend on both the entropy S and the gas density ρ. The cross helicity and fluid helicity conservation laws in the non-barotropic case are nonlocal conservation laws that reduce to local conservation laws for the case of a barotropic gas. The connections between gauge symmetries, Clebsch potentials and Casimirs are developed. It is shown that the gauge symmetry functionals in the work of Henyey (1982 Phys. Rev. A 26 480-3) satisfy the Casimir determining equations.

  8. A philosophical approach to quantum field theory

    CERN Document Server

    Öttinger, Hans Christian

    2015-01-01

    This text presents an intuitive and robust mathematical image of fundamental particle physics based on a novel approach to quantum field theory, which is guided by four carefully motivated metaphysical postulates. In particular, the book explores a dissipative approach to quantum field theory, which is illustrated for scalar field theory and quantum electrodynamics, and proposes an attractive explanation of the Planck scale in quantum gravity. Offering a radically new perspective on this topic, the book focuses on the conceptual foundations of quantum field theory and ontological questions. It also suggests a new stochastic simulation technique in quantum field theory which is complementary to existing ones. Encouraging rigor in a field containing many mathematical subtleties and pitfalls this text is a helpful companion for students of physics and philosophers interested in quantum field theory, and it allows readers to gain an intuitive rather than a formal understanding.

  9. A philosophical approach to quantum field theory

    CERN Document Server

    Öttinger, Hans Christian

    2017-01-01

    This text presents an intuitive and robust mathematical image of fundamental particle physics based on a novel approach to quantum field theory, which is guided by four carefully motivated metaphysical postulates. In particular, the book explores a dissipative approach to quantum field theory, which is illustrated for scalar field theory and quantum electrodynamics, and proposes an attractive explanation of the Planck scale in quantum gravity. Offering a radically new perspective on this topic, the book focuses on the conceptual foundations of quantum field theory and ontological questions. It also suggests a new stochastic simulation technique in quantum field theory which is complementary to existing ones. Encouraging rigor in a field containing many mathematical subtleties and pitfalls this text is a helpful companion for students of physics and philosophers interested in quantum field theory, and it allows readers to gain an intuitive rather than a formal understanding.

  10. Toward a gauge field theory of gravity.

    Science.gov (United States)

    Yilmaz, H.

    Joint use of two differential identities (Bianchi and Freud) permits a gauge field theory of gravity in which the gravitational energy is localizable. The theory is compatible with quantum mechanics and is experimentally viable.

  11. Towards weakly constrained double field theory

    Directory of Open Access Journals (Sweden)

    Kanghoon Lee

    2016-08-01

    Full Text Available We show that it is possible to construct a well-defined effective field theory incorporating string winding modes without using strong constraint in double field theory. We show that X-ray (Radon transform on a torus is well-suited for describing weakly constrained double fields, and any weakly constrained fields are represented as a sum of strongly constrained fields. Using inverse X-ray transform we define a novel binary operation which is compatible with the level matching constraint. Based on this formalism, we construct a consistent gauge transform and gauge invariant action without using strong constraint. We then discuss the relation of our result to the closed string field theory. Our construction suggests that there exists an effective field theory description for massless sector of closed string field theory on a torus in an associative truncation.

  12. Gauge field theories: various mathematical approaches

    OpenAIRE

    Jordan, François; Serge, Lazzarini; Thierry, Masson

    2014-01-01

    This paper presents relevant modern mathematical formulations for (classical) gauge field theories, namely, ordinary differential geometry, noncommutative geometry, and transitive Lie algebroids. They provide rigorous frameworks to describe Yang-Mills-Higgs theories or gravitation theories, and each of them improves the paradigm of gauge field theories. A brief comparison between them is carried out, essentially due to the various notions of connection. However they reveal a compelling common...

  13. Quantum field theory in gravitational background

    International Nuclear Information System (INIS)

    Narnhofer, H.

    1986-01-01

    The author suggests ignoring the influence of the quantum field on the gravitation as the first step to combine quantum field theory and gravitation theory, but to consider the gravitational field as fixed and thus study quantum field theory on a manifold. This subject evoked interest when thermal radiation of a black hole was predicted. The author concentrates on the free quantum field and can split the problem into two steps: the Weyl-algebra of the free field and the Wightman functional on the tangent space

  14. Analytic aspects of rational conformal field theories

    International Nuclear Information System (INIS)

    Kiritsis, E.B.; Lawrence Berkeley Lab., CA

    1990-01-01

    The problem of deriving linear differential equations for correlation functions of Rational Conformal Field Theories is considered. Techniques from the theory of fuchsian differential equations are used to show that knowledge of the central charge, dimensions of primary fields and fusion rules are enough to fix the differential equations for one- and two-point functions on the tours. Any other correlation function can be calculated along similar lines. The results settle the issue of 'exact solution' of rational conformal field theories. (orig.)

  15. Strings - Links between conformal field theory, gauge theory and gravity

    International Nuclear Information System (INIS)

    Troost, J.

    2009-05-01

    String theory is a candidate framework for unifying the gauge theories of interacting elementary particles with a quantum theory of gravity. The last years we have made considerable progress in understanding non-perturbative aspects of string theory, and in bringing string theory closer to experiment, via the search for the Standard Model within string theory, but also via phenomenological models inspired by the physics of strings. Despite these advances, many deep problems remain, amongst which a non-perturbative definition of string theory, a better understanding of holography, and the cosmological constant problem. My research has concentrated on various theoretical aspects of quantum theories of gravity, including holography, black holes physics and cosmology. In this Habilitation thesis I have laid bare many more links between conformal field theory, gauge theory and gravity. Most contributions were motivated by string theory, like the analysis of supersymmetry preserving states in compactified gauge theories and their relation to affine algebras, time-dependent aspects of the holographic map between quantum gravity in anti-de-Sitter space and conformal field theories in the bulk, the direct quantization of strings on black hole backgrounds, the embedding of the no-boundary proposal for a wave-function of the universe in string theory, a non-rational Verlinde formula and the construction of non-geometric solutions to supergravity

  16. Singularity theory and N = 2 superconformal field theories

    International Nuclear Information System (INIS)

    Warner, N.P.

    1989-01-01

    The N = 2 superconformal field theories that appear at the fixed points of the renormalization group flows of Landau-Ginsburg models are discussed. Some of the techniques of singularity theory are employed to deduce properties of these superconformal theories. These ideas are then used to deduce the relationship between Calabi-Yau compactifications and tensored discrete series models. The chiral rings of general N = 2 superconformal theories are also described. 14 refs

  17. Algebraic quantum field theory, perturbation theory, and the loop expansion

    International Nuclear Information System (INIS)

    Duetsch, M.; Fredenhagen, K.

    2001-01-01

    The perturbative treatment of quantum field theory is formulated within the framework of algebraic quantum field theory. We show that the algebra of interacting fields is additive, i.e. fully determined by its subalgebras associated to arbitrary small subregions of Minkowski space. We also give an algebraic formulation of the loop expansion by introducing a projective system A (n) of observables ''up to n loops'', where A (0) is the Poisson algebra of the classical field theory. Finally we give a local algebraic formulation for two cases of the quantum action principle and compare it with the usual formulation in terms of Green's functions. (orig.)

  18. Operator algebras and conformal field theory

    International Nuclear Information System (INIS)

    Gabbiani, F.; Froehlich, J.

    1993-01-01

    We define and study two-dimensional, chiral conformal field theory by the methods of algebraic field theory. We start by characterizing the vacuum sectors of such theories and show that, under very general hypotheses, their algebras of local observables are isomorphic to the unique hyperfinite type III 1 factor. The conformal net determined by the algebras of local observables is proven to satisfy Haag duality. The representation of the Moebius group (and presumably of the entire Virasoro algebra) on the vacuum sector of a conformal field theory is uniquely determined by the Tomita-Takesaki modular operators associated with its vacuum state and its conformal net. We then develop the theory of Mebius covariant representations of a conformal net, using methods of Doplicher, Haag and Roberts. We apply our results to the representation theory of loop groups. Our analysis is motivated by the desire to find a 'background-independent' formulation of conformal field theories. (orig.)

  19. Classical gravity and quantum matter fields in unified field theory

    Science.gov (United States)

    von Borzeszkowski, Horst-Heino; Treder, Hans-Jürgen

    1996-01-01

    The Einstein-Schrödinger purely affine field theory of the non-symmetric field provides canonical field equations without constraints. These equations imply the Heisenberg-Pauli commutation rules of quantum field theory. In the Schrödinger gauging of the Einstein field coordinatesU {/kl i }=Γ{/kl i }-δ{/l i }Γ{/km m }, this unified geometric field theory becomes a model of the coupling between a quantized Maxwellian field in a medium and classical gravity. Therefore, independently of the question as to the physical truth of this model, its analysis performed in the present paper demonstrates that, in the framework of a quantized unified field theory, gravity can appear as a genuinely classical field.

  20. Engineering of mixed pairing and non-Abelian Majorana states in chiral p-wave superconductor Sr2RuO4 and other materials

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ying [Pennsylvania State Univ., University Park, PA (United States). Dept. of Physics

    2015-11-30

    This project deals with odd-parity superconductor Sr2RuO4 and related material systems, aiming at understanding the unconventional nature of superconductivity in this material. An odd-parity superconductor is expected to feature a novel topological object, the half-flux-quantum vortex that hosts a Majorana anyons. Majorana anyons carry non-Abelian statistics that can be used as the building block for constructing a fault-tolerated topological quantum computer. Half-flux-quantum vortices form in an odd-parity superconductor because of the availability of charge neutral spin supercurrent in addition to the normal supercurrent. Half-height magnetization steps were found in a cantilever magnetometry measurement of doubly connected mesoscopic samples of Sr2RuO4 in the presence of an in-plane magnetic field (J. Jang, D. G. Ferguson, V. Vakaryuk, R. Budakian, S. B. Chung, P. M. Goldbart, and Y. Maeno, Science 331, 186 (2011)), which suggests the presence of a half-flux-quantum (Φ0/2 = h/4e) state. Evidence for half flux quantum states, which can be viewed as coreless half vortices, was obtained in mesoscopic samples of Sr2RuO4 in the torque magnetomitry measurements. However, the existence of such an important property has not been confirmed by any other independent measurement.

  1. Relativistic quantum mechanics and field theory

    CERN Document Server

    Gross, Franz

    1999-01-01

    An accessible, comprehensive reference to modern quantum mechanics and field theory.In surveying available books on advanced quantum mechanics and field theory, Franz Gross determined that while established books were outdated, newer titles tended to focus on recent developments and disregard the basics. Relativistic Quantum Mechanics and Field Theory fills this striking gap in the field. With a strong emphasis on applications to practical problems as well as calculations, Dr. Gross provides complete, up-to-date coverage of both elementary and advanced topics essential for a well-rounded understanding of the field.

  2. Mathematical aspects of quantum field theories

    CERN Document Server

    Strobl, Thomas

    2015-01-01

    Despite its long history and stunning experimental successes, the mathematical foundation of perturbative quantum field theory is still a subject of ongoing research. This book aims at presenting some of the most recent advances in the field, and at reflecting the diversity of approaches and tools invented and currently employed. Both leading experts and comparative newcomers to the field present their latest findings, helping readers to gain a better understanding of not only quantum but also classical field theories. Though the book offers a valuable resource for mathematicians and physicists alike, the focus is more on mathematical developments. This volume consists of four parts: The first Part covers local aspects of perturbative quantum field theory, with an emphasis on the axiomatization of the algebra behind the operator product expansion. The second Part highlights Chern-Simons gauge theories, while the third examines (semi-)classical field theories. In closing, Part 4 addresses factorization homolo...

  3. Holographic applications of logarithmic conformal field theories

    NARCIS (Netherlands)

    Grumiller, D.; Riedler, W.; Rosseel, J.; Zojer, T.

    2013-01-01

    We review the relations between Jordan cells in various branches of physics, ranging from quantum mechanics to massive gravity theories. Our main focus is on holographic correspondences between critically tuned gravity theories in anti-de Sitter space and logarithmic conformal field theories in

  4. New results in topological field theory and Abelian gauge theory

    International Nuclear Information System (INIS)

    Thompson, G.

    1995-10-01

    These are the lecture notes of a set of lectures delivered at the 1995 Trieste summer school in June. I review some recent work on duality in four dimensional Maxwell theory on arbitrary four manifolds, as well as a new set of topological invariants known as the Seiberg-Witten invariants. Much of the necessary background material is given, including a crash course in topological field theory, cohomology of manifolds, topological gauge theory and the rudiments of four manifold theory. My main hope is to wet the readers appetite, so that he or she will wish to read the original works and perhaps to enter this field. (author). 41 refs, 5 figs

  5. Adiabatic regularization for gauge fields and the conformal anomaly

    Science.gov (United States)

    Chu, Chong-Sun; Koyama, Yoji

    2017-03-01

    Adiabatic regularization for quantum field theory in conformally flat spacetime is known for scalar and Dirac fermion fields. In this paper, we complete the construction by establishing the adiabatic regularization scheme for the gauge field. We show that the adiabatic expansion for the mode functions and the adiabatic vacuum can be defined in a similar way using Wentzel-Kramers-Brillouin-type (WKB-type) solutions as the scalar fields. As an application of the adiabatic method, we compute the trace of the energy momentum tensor and reproduce the known result for the conformal anomaly obtained by the other regularization methods. The availability of the adiabatic expansion scheme for the gauge field allows one to study various renormalized physical quantities of theories coupled to (non-Abelian) gauge fields in conformally flat spacetime, such as conformal supersymmetric Yang Mills, inflation, and cosmology.

  6. Topological quantum field theory and four manifolds

    CERN Document Server

    Marino, Marcos

    2005-01-01

    The present book is the first of its kind in dealing with topological quantum field theories and their applications to topological aspects of four manifolds. It is not only unique for this reason but also because it contains sufficient introductory material that it can be read by mathematicians and theoretical physicists. On the one hand, it contains a chapter dealing with topological aspects of four manifolds, on the other hand it provides a full introduction to supersymmetry. The book constitutes an essential tool for researchers interested in the basics of topological quantum field theory, since these theories are introduced in detail from a general point of view. In addition, the book describes Donaldson theory and Seiberg-Witten theory, and provides all the details that have led to the connection between these theories using topological quantum field theory. It provides a full account of Witten’s magic formula relating Donaldson and Seiberg-Witten invariants. Furthermore, the book presents some of the ...

  7. Worked examples in engineering field theory

    CERN Document Server

    Fuller, A J Baden

    1976-01-01

    Worked Examples in Engineering Field Theory is a product of a lecture course given by the author to first-year students in the Department of Engineering in the University of Leicester. The book presents a summary of field theory together with a large number of worked examples and solutions to all problems given in the author's other book, Engineering Field Theory. The 14 chapters of this book are organized into two parts. Part I focuses on the concept of flux including electric flux. This part also tackles the application of the theory in gravitation, ideal fluid flow, and magnetism. Part II d

  8. Introduction to algebraic quantum field theory

    International Nuclear Information System (INIS)

    Horuzhy, S.S.

    1990-01-01

    This volume presents a systematic introduction to the algebraic approach to quantum field theory. The structure of the contents corresponds to the way the subject has advanced. It is shown how the algebraic approach has developed from the purely axiomatic theory of observables via superselection rules into the dynamical formalism of fields and observables. Chapter one discusses axioms and their consequences -many of which are now classical theorems- and deals, in general, with the axiomatic theory of local observable algebras. The absence of field concepts makes this theory incomplete and, in chapter two, superselection rules are shown to be the key to the reconstruction of fields from observables. Chapter three deals with the algebras of Wightman fields, first unbounded operator algebras, then Von Neumann field algebras (with a special section on wedge region algebras) and finally local algebras of free and generalised free fields. (author). 447 refs.; 4 figs

  9. Using field theory in hadron physics

    International Nuclear Information System (INIS)

    Abarbanel, H.D.I.

    1978-03-01

    Topics are covered on the connection of field theory and hadron physics. The renormalization group and infrared and ultraviolet limits of field theory, in particular quantum chromodynamics, spontaneous mass generation, color confinement, instantons, and the vacuum state in quantum chromodynamics are treated. 21 references

  10. Calculations in perturbative string field theory

    International Nuclear Information System (INIS)

    Thorn, C.B.

    1987-01-01

    The author discusses methods for evaluating the Feynman diagrams of string field theory, with particular emphasis on Witten's version of open string field theory. It is explained in some detail how the rules states by Giddings and Martinec for relating a given diagram to a Polyakov path integral emerge from the Feynman rules

  11. An introduction to conformal field theory

    International Nuclear Information System (INIS)

    Zuber, J.B.

    1995-01-01

    The aim of these lectures is to present an introduction at a fairly elementary level to recent developments in two dimensional field theory, namely in conformal field theory. We shall see the importance of new structures related to infinite dimensional algebras: current algebras and Virasoro algebra. These topics will find physically relevant applications in the lectures by Shankar and Ian Affeck. (author)

  12. Using field theory in hadron physics

    Energy Technology Data Exchange (ETDEWEB)

    Abarbanel, H.D.I.

    1978-03-01

    Topics are covered on the connection of field theory and hadron physics. The renormalization group and infrared and ultraviolet limits of field theory, in particular quantum chromodynamics, spontaneous mass generation, color confinement, instantons, and the vacuum state in quantum chromodynamics are treated. 21 references. (JFP)

  13. Semiclassical Quantization of Classical Field Theories

    NARCIS (Netherlands)

    Cattaneo, A.; Mnev, P.; Reshetikhin, N.; Calaque, D.; Strobi, Th.

    2015-01-01

    Abstract These lectures are an introduction to formal semiclassical quantization of classical field theory. First we develop the Hamiltonian formalism for classical field theories on space time with boundary. It does not have to be a cylinder as in the usual Hamiltonian framework. Then we outline

  14. On the interplay between string theory and field theory

    International Nuclear Information System (INIS)

    Brunner, I.

    1998-01-01

    In this thesis, we have discussed various aspects of branes in string theory and M-theory. In chapter 2 we were able to construct six-dimensional chiral interacting eld theories from Hanany-Witten like brane setups. The field theory requirement that the anomalies cancel was reproduced by RR-charge conservation in the brane setup. The data of the Hanany-Witten setup, which consists of brane positions, was mapped to instanton data. The orbifold construction can be extended to D and E type singularities. In chapter 3 we discussed a matrix conjecture, which claims that M-theory in the light cone gauge is described by the quantum mechanics of D0 branes. Toroidal compactifications of M-theory have a description in terms of super Yang-Mills theory an the dual torus. For more than three compactified dimensions, more degrees of freedom have to be added. In some sense, the philosophy in this chapter is orthogonal to the previous chapter: Here, we want to get M-theory results from eld theory considerations, whereas in the previous chapter we obtained eld theory results by embedding the theories in string theory. Our main focus was on the compactification on T 6 , which leads to complications. Here, the Matrix model is again given by an eleven dimensional theory, not by a lower dimensional field theory. Other problems and possible resolutions of Matrix theory are discussed at the end of chapter 3. In the last chapter we considered M- and F-theory compactifications on Calabi-Yau fourfolds. After explaining some basics of fourfolds, we showed that the web of fourfolds is connected by singular transitions. The two manifolds which are connected by the transition are different resolutions of the same singular manifold. The resolution of the singularities can lead to a certain type of divisors, which lead to non-perturbative superpotentials, when branes wrap them. The vacua connected by the transitions can be physically very different. (orig.)

  15. Quantum Field Theory in a Semiotic Perspective

    CERN Document Server

    Günter Dosch, Hans; Sieroka, Norman

    2005-01-01

    Viewing physical theories as symbolic constructions came to the fore in the middle of the nineteenth century with the emancipation of the classical theory of the electromagnetic field from mechanics; most notably this happened through the work of Helmholtz, Hertz, Poincaré, and later Weyl. The epistemological problems that nourished this development are today highlighted within quantum field theory. The present essay starts off with a concise and non-technical outline of the firmly based aspects of relativistic quantum field theory, i.e. the very successful description of subnuclear phenomena. The particular methods, by which these different aspects have to be accessed, then get described as distinct facets of quantum field theory. The authors show how these different facets vary with respect to the relation between quantum fields and associated particles. Thus, by emphasising the respective role of various basic concepts involved, the authors claim that only a very general epistemic approach can properly ac...

  16. Introduction to field theory of strings

    International Nuclear Information System (INIS)

    Kikkawa, K.

    1987-01-01

    The field theory of bosonic string is reviewed. First, theory is treated in a light-cone gauge. After a brief survey of the first quantized theory of free string, the second quantization is discussed. All possible interactions of strings are introduced based on a smoothness condition of work sheets swept out by strings. Perturbation theory is developed. Finally a possible way to the manifest covariant formalism is discussed

  17. Gauge fields

    International Nuclear Information System (INIS)

    Mills, R.

    1989-01-01

    This article is a survey of the history and ideas of gauge theory. Described here are the gradual emergence of symmetry as a driving force in the shaping of physical theory; the elevation of Noether's theorem, relating symmetries to conservation laws, to a fundamental principle of nature; and the force of the idea (''the gauge principle'') that the symmetries of nature, like the interactions themselves, should be local in character. The fundamental role of gauge fields in mediating the interactions of physics springs from Noether's theorem and the gauge principle in a remarkably clean and elegant way, leaving, however, some tantalizing loose ends that might prove to be the clue to a future deeper level of understanding. The example of the electromagnetic field as the prototype gauge theory is discussed in some detail and serves as the basis for examining the similarities and differences that emerge in generalizing to non-Abelian gauge theories. The article concludes with a brief examination of the dream of total unification: all the forces of nature in a single unified gauge theory, with the differences among the forces due to the specific way in which the fundamental symmetries are broken in the local environment

  18. Austerity and geometric structure of field theories

    International Nuclear Information System (INIS)

    Kheyfets, A.

    1986-01-01

    The relation between the austerity idea and the geometric structure of the three basic field theories - electrodynamics, Yang-Mills theory, and general relativity - is studied. One of the most significant manifestations of the austerity idea in field theories is thought to be expressed by the boundary of a boundary principle (BBP). The BBP says that almost all content of the field theories can be deduced from the topological identity of delta dot produced with delta = 0 used twice, at the 1-2-3-dimensional level (providing the homogeneous field equations), and at the 2-3-4-dimensional level (providing the conservation laws for the source currents). There are some difficulties in this line of thought due to the apparent lack of universality in application of the BBP to the three basic modern field theories above. This dissertation: (a) analyzes the difficulties by means of algebraic topology, integration theory, and modern differential geometry based on the concepts of principal bundles and Ehresmann connections: (b) extends the BBP to the unified Kaluza-Klein theory; (c) reformulates the inhomogeneous field equations and the BBP in terms of E. Cartan moment of rotation, in the way universal for the three theories and compatible with the original austerity idea; and (d) underlines the important role of the soldering structure on spacetime, and indicates that the future development of the austerity idea would involve the generalized theories

  19. Schrodinger representation in renormalizable quantum field theory

    International Nuclear Information System (INIS)

    Symanzik, K.

    1983-01-01

    The problem of the Schrodinger representation arose from work on the Nambu-Goto Ansatz for integration over surfaces. Going beyond semiclassical approximation leads to two problems of nonrenormalizibility and of whether Dirichlet boundary conditions can be imposed on a ''Euclidean'' quantum field theory. The Schrodinger representation is constructed in a way where the principles of general renormalization theory can be refered to. The Schrodinger function of surface terms is studied, as well as behaviour at the boundary. The Schrodinger equation is derived. Completeness, unitarity, and computation of expectation values are considered. Extensions of these methods into other Bose field theories such as Fermi fields and Marjorana fields is straightforward

  20. Local algebras in Euclidean quantum field theory

    International Nuclear Information System (INIS)

    Guerra, Francesco.

    1975-06-01

    The general structure of the local observable algebras of Euclidean quantum field theory is described, considering the very simple examples of the free scalar field, the vector meson field, and the electromagnetic field. The role of Markov properties, and the relations between Euclidean theory and Hamiltonian theory in Minkowski space-time are especially emphasized. No conflict appears between covariance (in the Euclidean sense) and locality (in the Markov sense) on one hand and positive definiteness of the metric on the other hand [fr

  1. Mathematical aspects of quantum field theory

    CERN Document Server

    de Faria, Edson

    2010-01-01

    Over the last century quantum field theory has made a significant impact on the formulation and solution of mathematical problems and inspired powerful advances in pure mathematics. However, most accounts are written by physicists, and mathematicians struggle to find clear definitions and statements of the concepts involved. This graduate-level introduction presents the basic ideas and tools from quantum field theory to a mathematical audience. Topics include classical and quantum mechanics, classical field theory, quantization of classical fields, perturbative quantum field theory, renormalization, and the standard model. The material is also accessible to physicists seeking a better understanding of the mathematical background, providing the necessary tools from differential geometry on such topics as connections and gauge fields, vector and spinor bundles, symmetries and group representations.

  2. Supersymmetry and Duality in Field Theory and String Theory

    CERN Document Server

    Kiritsis, Elias B

    1999-01-01

    This is a set of lectures given at the 99' Cargese Summer School, "Particle Physics : Ideas and Recent Developments". They contain a pedestrian exposition of recent theoretical progress in non-perturbative field theory and string theory based on ideas of duality.

  3. Introduction to conformal field theory and string theory

    International Nuclear Information System (INIS)

    Dixon, L.J.

    1989-12-01

    These lectures are meant to provide a brief introduction to conformal field theory (CFT) and string theory for those with no prior exposure to the subjects. There are many excellent reviews already available, and most of these go in to much more detail than I will be able to here. 52 refs., 11 figs

  4. Introduction to conformal field theory and string theory

    Energy Technology Data Exchange (ETDEWEB)

    Dixon, L.J.

    1989-12-01

    These lectures are meant to provide a brief introduction to conformal field theory (CFT) and string theory for those with no prior exposure to the subjects. There are many excellent reviews already available, and most of these go in to much more detail than I will be able to here. 52 refs., 11 figs.

  5. String field theory in curved space

    International Nuclear Information System (INIS)

    Kikkawa, Keiji; Maeno, Masahiro; Sawada, Shiro

    1988-01-01

    The purely cubic action in the string field theory is shown to provide a set of equations of motion for background fields which agree to those obtained by the vanishing condition of β-functions in the non-linear sigma model. Using the sigma model as an auxiliary tool, a systematic method for solving the string field theory in curved space is proposed. (author)

  6. Inflating with large effective fields

    Energy Technology Data Exchange (ETDEWEB)

    Burgess, C.P. [PH-TH Division, CERN, CH-1211, Genève 23 (Switzerland); Cicoli, M. [Dipartimento di Fisica e Astronomia, Università di Bologna, Via Irnerio 46, 40126 Bologna (Italy); Quevedo, F. [Abdus Salam ICTP, Strada Costiera 11, Trieste 34014 (Italy); Williams, M., E-mail: cburgess@perimeterinstitute.ca, E-mail: mcicoli@ictp.it, E-mail: f.quevedo@damtp.cam.ac.uk, E-mail: mwilliams@perimeterinsititute.ca [Department of Physics and Astronomy, McMaster University, 1280 Main Street West, Hamilton ON (Canada)

    2014-11-01

    We re-examine large scalar fields within effective field theory, in particular focussing on the issues raised by their use in inflationary models (as suggested by BICEP2 to obtain primordial tensor modes). We argue that when the large-field and low-energy regimes coincide the scalar dynamics is most effectively described in terms of an asymptotic large-field expansion whose form can be dictated by approximate symmetries, which also help control the size of quantum corrections. We discuss several possible symmetries that can achieve this, including pseudo-Goldstone inflatons characterized by a coset G/H (based on abelian and non-abelian, compact and non-compact symmetries), as well as symmetries that are intrinsically higher dimensional. Besides the usual trigonometric potentials of Natural Inflation we also find in this way simple large-field power laws (like V ∝ φ{sup 2}) and exponential potentials, V(φ) = ∑{sub k}V{sub x}e{sup −kφ/M}. Both of these can describe the data well and give slow-roll inflation for large fields without the need for a precise balancing of terms in the potential. The exponential potentials achieve large r through the limit |η| || ε and so predict r ≅ (8/3)(1-n{sub s}); consequently n{sub s} ≅ 0.96 gives r ≅ 0.11 but not much larger (and so could be ruled out as measurements on r and n{sub s} improve). We examine the naturalness issues for these models and give simple examples where symmetries protect these forms, using both pseudo-Goldstone inflatons (with non-abelian non-compact shift symmetries following familiar techniques from chiral perturbation theory) and extra-dimensional models.

  7. Inflating with large effective fields

    Science.gov (United States)

    Burgess, C. P.; Cicoli, M.; Quevedo, F.; Williams, M.

    2014-11-01

    We re-examine large scalar fields within effective field theory, in particular focussing on the issues raised by their use in inflationary models (as suggested by BICEP2 to obtain primordial tensor modes). We argue that when the large-field and low-energy regimes coincide the scalar dynamics is most effectively described in terms of an asymptotic large-field expansion whose form can be dictated by approximate symmetries, which also help control the size of quantum corrections. We discuss several possible symmetries that can achieve this, including pseudo-Goldstone inflatons characterized by a coset G/H (based on abelian and non-abelian, compact and non-compact symmetries), as well as symmetries that are intrinsically higher dimensional. Besides the usual trigonometric potentials of Natural Inflation we also find in this way simple large-field power laws (like V propto phi2) and exponential potentials, V(phi) = ∑kVxe-kphi/M. Both of these can describe the data well and give slow-roll inflation for large fields without the need for a precise balancing of terms in the potential. The exponential potentials achieve large r through the limit |η| ll epsilon and so predict r simeq (8/3)(1-ns) consequently ns simeq 0.96 gives r simeq 0.11 but not much larger (and so could be ruled out as measurements on r and ns improve). We examine the naturalness issues for these models and give simple examples where symmetries protect these forms, using both pseudo-Goldstone inflatons (with non-abelian non-compact shift symmetries following familiar techniques from chiral perturbation theory) and extra-dimensional models.

  8. Light-front quantization of field theory

    Energy Technology Data Exchange (ETDEWEB)

    Srivastava, Prem P. [Universidade do Estado, Rio de Janeiro, RJ (Brazil). Inst. de Fisica]|[Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil)

    1996-07-01

    Some basic topics in Light-Front (LF) quantized field theory are reviewed. Poincare algebra and the LF spin operator are discussed. The local scalar field theory of the conventional framework is shown to correspond to a non-local Hamiltonian theory on the LF in view of the constraint equations on the phase space, which relate the bosonic condensates to the non-zero modes. This new ingredient is useful to describe the spontaneous symmetry breaking on the LF. The instability of the symmetric phase in two dimensional scalar theory when the coupling constant grows is shown in the LF theory renormalized to one loop order. Chern-Simons gauge theory, regarded to describe excitations with fractional statistics, is quantized in the light-cone gauge and a simple LF Hamiltonian obtained which may allow us to construct renormalized theory of anyons. (author). 20 refs.

  9. Field theory of relativistic strings: I. Trees

    International Nuclear Information System (INIS)

    Kaku, M.; Kikkawa, K.

    1985-01-01

    The authors present an entirely new kind of field theory, a field theory quantized not at space-time points, but quantized along an extended set of multilocal points on a string. This represents a significant departure from the usual quantum field theory, whose free theory represents a definite set of elementary particles, because the field theory on relativistic strings can accommodate an infinite set of linearly rising Regge trajectories. In this paper, the authors (1) present canonical quantization and the Green's function of the free string, (2) introduce three-string interactions, (3) resolve the question of multiple counting, (4) complete the counting arguments for all N-point trees, and (5) introduce four-string interactions which yield a Yang-Mills structure when the zero-slope limit is taken

  10. A Field Theory with Curvature and Anticurvature

    Directory of Open Access Journals (Sweden)

    M. I. Wanas

    2014-01-01

    Full Text Available The present work is an attempt to construct a unified field theory in a space with curvature and anticurvature, the PAP-space. The theory is derived from an action principle and a Lagrangian density using a symmetric linear parameterized connection. Three different methods are used to explore physical contents of the theory obtained. Poisson’s equations for both material and charge distributions are obtained, as special cases, from the field equations of the theory. The theory is a pure geometric one in the sense that material distribution, charge distribution, gravitational and electromagnetic potentials, and other physical quantities are defined in terms of pure geometric objects of the structure used. In the case of pure gravity in free space, the spherical symmetric solution of the field equations gives the Schwarzschild exterior field. The weak equivalence principle is respected only in the case of pure gravity in free space; otherwise it is violated.

  11. Mass corrections in string theory and lattice field theory

    International Nuclear Information System (INIS)

    Del Debbio, Luigi; Kerrane, Eoin; Russo, Rodolfo

    2009-01-01

    Kaluza-Klein (KK) compactifications of higher-dimensional Yang-Mills theories contain a number of 4-dimensional scalars corresponding to the internal components of the gauge field. While at tree level the scalar zero modes are massless, it is well known that quantum corrections make them massive. We compute these radiative corrections at 1 loop in an effective field theory framework, using the background field method and proper Schwinger-time regularization. In order to clarify the proper treatment of the sum over KK modes in the effective field theory approach, we consider the same problem in two different UV completions of Yang-Mills: string theory and lattice field theory. In both cases, when the compactification radius R is much bigger than the scale of the UV completion (R>>√(α ' ), a), we recover a mass renormalization that is independent of the UV scale and agrees with the one derived in the effective field theory approach. These results support the idea that the value of the mass corrections is, in this regime, universal for any UV completion that respects locality and gauge invariance. The string analysis suggests that this property holds also at higher loops. The lattice analysis suggests that the mass of the adjoint scalars appearing in N=2, 4 super Yang-Mills is highly suppressed, even if the lattice regularization breaks all supersymmetries explicitly. This is due to an interplay between the higher-dimensional gauge invariance and the degeneracy of bosonic and fermionic degrees of freedom.

  12. Fermion boson metamorphosis in field theory

    International Nuclear Information System (INIS)

    Ha, Y.K.

    1982-01-01

    In two-dimensional field theories many features are especially transparent if the Fermi fields are represented by non-local expressions of the Bose fields. Such a procedure is known as boson representation. Bilinear quantities appear in the Lagrangian of a fermion theory transform, however, as simple local expressions of the bosons so that the resulting theory may be written as a theory of bosons. Conversely, a theory of bosons may be transformed into an equivalent theory of fermions. Together they provide a basis for generating many interesting equivalences between theories of different types. In the present work a consistent scheme for constructing a canonical Fermi field in terms of a real scalar field is developed and such a procedure is valid and consistent with the tenets of quantum field theory is verified. A boson formulation offers a unifying theme in understanding the structure of many theories. This is illustrated by the boson formulation of a multifermion theory with chiral and internal symmetries. The nature of dynamical generation of mass when the theory undergoes boson transmutation and the preservation of continuous chiral symmetry in the massive case are examined. The dynamics of the system depends to a great extent on the specific number of fermions and different models of the same system can have very different properties. Many unusual symmetries of the fermion theory, such as hidden symmetry, duality and triality symmetries, are only manifest in the boson formulation. The underlying connections between some models with U(N) internal symmetry and another class of fermion models built with Majorana fermions which have O(2N) internal symmetry are uncovered

  13. Abelian gauge theories with tensor gauge fields

    International Nuclear Information System (INIS)

    Kapuscik, E.

    1984-01-01

    Gauge fields of arbitrary tensor type are introduced. In curved space-time the gravitational field serves as a bridge joining different gauge fields. The theory of second order tensor gauge field is developed on the basis of close analogy to Maxwell electrodynamics. The notion of tensor current is introduced and an experimental test of its detection is proposed. The main result consists in a coupled set of field equations representing a generalization of Maxwell theory in which the Einstein equivalence principle is not satisfied. (author)

  14. Introduction to classical and quantum field theory

    International Nuclear Information System (INIS)

    Ng, Tai-Kai

    2009-01-01

    This is the first introductory textbook on quantum field theory to be written from the point of view of condensed matter physics. As such, it presents the basic concepts and techniques of statistical field theory, clearly explaining how and why they are integrated into modern quantum (and classical) field theory, and includes the latest developments. Written by an expert in the field, with a broad experience in teaching and training, it manages to present such substantial topics as phases and phase transitions or solitons and instantons in an accessible and concise way. Divided into three parts, the first part covers fundamental physics and the mathematics background needed by students in order to enter the field, while the second part introduces more advanced concepts and techniques. Part III discusses applications of quantum field theory to a few basic problems. The emphasis here lies on how modern concepts of quantum field theory are embedded in these approaches, and also on the limitations of standard quantum field theory techniques in facing, 'real' physics problems. Throughout there are numerous end-of-chapter problems, and a free solutions manual is available for lecturers. (orig.)

  15. M(atrix) theory: matrix quantum mechanics as a fundamental theory

    International Nuclear Information System (INIS)

    Taylor, Washington

    2001-01-01

    This article reviews the matrix model of M theory. M theory is an 11-dimensional quantum theory of gravity that is believed to underlie all superstring theories. M theory is currently the most plausible candidate for a theory of fundamental physics which reconciles gravity and quantum field theory in a realistic fashion. Evidence for M theory is still only circumstantial -- no complete background-independent formulation of the theory exists as yet. Matrix theory was first developed as a regularized theory of a supersymmetric quantum membrane. More recently, it has appeared in a different guise as the discrete light-cone quantization of M theory in flat space. These two approaches to matrix theory are described in detail and compared. It is shown that matrix theory is a well-defined quantum theory that reduces to a supersymmetric theory of gravity at low energies. Although its fundamental degrees of freedom are essentially pointlike, higher-dimensional fluctuating objects (branes) arise through the non-Abelian structure of the matrix degrees of freedom. The problem of formulating matrix theory in a general space-time background is discussed, and the connections between matrix theory and other related models are reviewed

  16. Effective theories of single field inflation when heavy fields matter

    CERN Document Server

    Achucarro, Ana; Hardeman, Sjoerd; Palma, Gonzalo A; Patil, Subodh P

    2012-01-01

    We compute the low energy effective field theory (EFT) expansion for single-field inflationary models that descend from a parent theory containing multiple other scalar fields. By assuming that all other degrees of freedom in the parent theory are sufficiently massive relative to the inflaton, it is possible to derive an EFT valid to arbitrary order in perturbations, provided certain generalized adiabaticity conditions are respected. These conditions permit a consistent low energy EFT description even when the inflaton deviates off its adiabatic minimum along its slowly rolling trajectory. By generalizing the formalism that identifies the adiabatic mode with the Goldstone boson of this spontaneously broken time translational symmetry prior to the integration of the heavy fields, we show that this invariance of the parent theory dictates the entire non-perturbative structure of the descendent EFT. The couplings of this theory can be written entirely in terms of the reduced speed of sound of adiabatic perturbat...

  17. Conformal techniques in string theory and string field theory

    International Nuclear Information System (INIS)

    Giddings, S.B.

    1987-01-01

    The application of some conformal and Riemann surface techniques to string theory and string field theory is described. First a brief review of Riemann surface techniques and of the Polyakov approach to string theory is presented. This is followed by a discussion of some features of string field theory and of its Feynman rules. Specifically, it is shown that the Feynman diagrams for Witten's string field theory respect modular invariance, and in particular give a triangulation of moduli space. The Polyakov formalism is then used to derive the Feynman rules that should follow from this theory upon gauge-fixing. It should also be possible to apply this derivation to deduce the Feynman rules for other gauge-fixed string field theories. Following this, Riemann surface techniques are turned to the problem of proving the equivalence of the Polyakov and light-cone formalisms. It is first shown that the light-cone diagrams triangulate moduli space. Then the Polyakov measure is worked out for these diagrams, and shown to equal that deduced from the light-cone gauge fixed formalism. Also presented is a short description of the comparison of physical states in the two formalisms. The equivalence of the two formalisms in particular constitutes a proof of the unitarity of the Polyakov framework for the closed bosonic string

  18. [Studies in quantum field theory]: Progress report

    International Nuclear Information System (INIS)

    Polmar, S.K.

    1988-01-01

    The theoretical physics group at Washington University has been devoted to the solution of problems in theoretical and mathematical physics. All of the personnel on this task have a similar approach to their research in that they apply sophisticated analytical and numerical techniques to problems primarily in quantum field theory. Specifically, this group has worked on quantum chromodynamics, classical Yang-Mills fields, chiral symmetry breaking condensates, lattice field theory, strong-coupling approximations, perturbation theory in large order, nonlinear waves, 1/N expansions, quantum solitons, phase transitions, nuclear potentials, and early universe calculations

  19. Effective field theory for NN interactions

    International Nuclear Information System (INIS)

    Tran Duy Khuong; Vo Hanh Phuc

    2003-01-01

    The effective field theory of NN interactions is formulated and the power counting appropriate to this case is reviewed. It is more subtle than in most effective field theories since in the limit that the S-wave NN scattering lengths go to infinity. It is governed by nontrivial fixed point. The leading two body terms in the effective field theory for nucleon self interactions are scale invariant and invariant under Wigner SU(4) spin-isospin symmetry in this limit. Higher body terms with no derivatives (i.e. three and four body terms) are automatically invariant under Wigner symmetry. (author)

  20. Polynomial field theories and nonintegrability

    International Nuclear Information System (INIS)

    Euler, N.; Steeb, W.H.; Cyrus, K.

    1990-01-01

    The nonintegrability of the nonlinear field equation v ηξ = v 3 is studied with the help of the Painleve test. The condition at the resonance is discussed in detail. Particular solutions are given. (orig.)

  1. Conformal field theories and tensor categories. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Bai, Chengming [Nankai Univ., Tianjin (China). Chern Institute of Mathematics; Fuchs, Juergen [Karlstad Univ. (Sweden). Theoretical Physics; Huang, Yi-Zhi [Rutgers Univ., Piscataway, NJ (United States). Dept. of Mathematics; Kong, Liang [Tsinghua Univ., Beijing (China). Inst. for Advanced Study; Runkel, Ingo; Schweigert, Christoph (eds.) [Hamburg Univ. (Germany). Dept. of Mathematics

    2014-08-01

    First book devoted completely to the mathematics of conformal field theories, tensor categories and their applications. Contributors include both mathematicians and physicists. Some long expository articles are especially suitable for beginners. The present volume is a collection of seven papers that are either based on the talks presented at the workshop ''Conformal field theories and tensor categories'' held June 13 to June 17, 2011 at the Beijing International Center for Mathematical Research, Peking University, or are extensions of the material presented in the talks at the workshop. These papers present new developments beyond rational conformal field theories and modular tensor categories and new applications in mathematics and physics. The topics covered include tensor categories from representation categories of Hopf algebras, applications of conformal field theories and tensor categories to topological phases and gapped systems, logarithmic conformal field theories and the corresponding non-semisimple tensor categories, and new developments in the representation theory of vertex operator algebras. Some of the papers contain detailed introductory material that is helpful for graduate students and researchers looking for an introduction to these research directions. The papers also discuss exciting recent developments in the area of conformal field theories, tensor categories and their applications and will be extremely useful for researchers working in these areas.

  2. Metric quantum field theory: A preliminary look

    International Nuclear Information System (INIS)

    Watson, W.N.

    1988-01-01

    Spacetime coordinates are involved in uncertainty relations; spacetime itself appears to exhibit curvature. Could the continua associated with field variables exhibit curvature? This question, as well as the ideas that (a) difficulties with quantum theories of gravitation may be due to their formulation in an incorrect analogy with other quantum field theories, (b) spacetime variables should not be any more basic than others for describing physical phenomena, and (c) if field continua do not exhibit curvature, the reasons would be of interest, motivated the formulation of a theory of variable curvature and torsion in the electromagnetic four-potential's reciprocal space. Curvature and torsion equation completely analogous to those for a gauge theory of gravitation (the Einstein-Cartan-Sciama-Kibble theory) are assumed for this continuum. The interaction-Hamiltonian density of this theory, to a first approximation, implies that in addition to the Maxwell-Dirac field interaction of ordinary quantum electrodynamics, there should also be an interaction between Dirac-field vector and pseudovector currents unmediated by photons, as well as other interactions involving two or three Dirac-field currents interacting with the Maxwell field at single spacetime events. Calculations expressing Bhabha-scattering cross sections for incident beams with parallel spins differ from those of unmodified quantum electrodynamics by terms of first order in the gravitational constant of the theory, but the corresponding cross section for unpolarized incident beams differs from that of the unmodified theory only by terms of higher order in that constant. Undesirable features of the present theory include its nonrenormalizability, the obscurity of the meaning of its inverse field operator, and its being based on electrodynamics rather than electroweak dynamics

  3. The conceptual framework of quantum field theory

    CERN Document Server

    Duncan, Anthony

    2012-01-01

    The book attempts to provide an introduction to quantum field theory emphasizing conceptual issues frequently neglected in more "utilitarian" treatments of the subject. The book is divided into four parts, entitled respectively "Origins", "Dynamics", "Symmetries", and "Scales". The emphasis is conceptual - the aim is to build the theory up systematically from some clearly stated foundational concepts - and therefore to a large extent anti-historical, but two historical Chapters ("Origins") are included to situate quantum field theory in the larger context of modern physical theories. The three remaining sections of the book follow a step by step reconstruction of this framework beginning with just a few basic assumptions: relativistic invariance, the basic principles of quantum mechanics, and the prohibition of physical action at a distance embodied in the clustering principle. The "Dynamics" section of the book lays out the basic structure of quantum field theory arising from the sequential insertion of quan...

  4. Factorization algebras in quantum field theory

    CERN Document Server

    Costello, Kevin

    2017-01-01

    Factorization algebras are local-to-global objects that play a role in classical and quantum field theory which is similar to the role of sheaves in geometry: they conveniently organize complicated information. Their local structure encompasses examples like associative and vertex algebras; in these examples, their global structure encompasses Hochschild homology and conformal blocks. In this first volume, the authors develop the theory of factorization algebras in depth, but with a focus upon examples exhibiting their use in field theory, such as the recovery of a vertex algebra from a chiral conformal field theory and a quantum group from Abelian Chern-Simons theory. Expositions of the relevant background in homological algebra, sheaves and functional analysis are also included, thus making this book ideal for researchers and graduates working at the interface between mathematics and physics.

  5. Magnetic fields, special relativity and potential theory elementary electromagnetic theory

    CERN Document Server

    Chirgwin, B H; Kilmister, C W

    1972-01-01

    Magnetic Fields, Special Relativity and Potential Theory is an introduction to electromagnetism, special relativity, and potential theory, with emphasis on the magnetic field of steady currents (magnetostatics). Topics covered range from the origin of the magnetic field and the magnetostatic scalar potential to magnetization, electromagnetic induction and magnetic energy, and the displacement current and Maxwell's equations. This volume is comprised of five chapters and begins with an overview of magnetostatics, followed by a chapter on the methods of solving potential problems drawn from elec

  6. Thermo field dynamics: a quantum field theory at finite temperature

    International Nuclear Information System (INIS)

    Mancini, F.; Marinaro, M.; Matsumoto, H.

    1988-01-01

    A brief review of the theory of thermo field dynamics (TFD) is presented. TFD is introduced and developed by Umezawa and his coworkers at finite temperature. The most significant concept in TFD is that of a thermal vacuum which satisfies some conditions denoted as thermal state conditions. The TFD permits to reformulate theories at finite temperature. There is no need in an additional principle to determine particle distributions at T ≠ 0. Temperature and other macroscopic parameters are introduced in the definition of the vacuum state. All operator formalisms used in quantum field theory at T=0 are preserved, although the field degrees of freedom are doubled. 8 refs

  7. String theory inspired deformations of quantum field theories

    Science.gov (United States)

    Chiou, Dah-Wei

    In this dissertation, some extensions on field theories with deformations inspired by string theory are explored and their implications are investigated. These are: (i) noncommutative dipole field theory (DFT) and unitarity; (ii) three dimensional super Yang-Mills theory and mini-twistor string theory; (iii) massive super Yang-Mills theory and twistor string theory; and (iv) a deformation of twistor space and N = 4 super Yang-Mills theory with a chiral mass term. The DFT with fixed spacetime vectors ("dipole-vectors") is formulated for gauge theory coupled with a scalar field of adjoint charge. The argument for the violation of unitarity in field theories on a noncommutative spacetime is extended to the case of DFT: with a timelike dipole vector, 1-loop amplitudes are shown not to obey the optical theorem and thus violate unitarity. Likewise, a simple 0 + 1D quantum mechanical system with nonlocal potential of finite extent in time also gives violation of unitarity. Associated with D = 3 super Yang-Mills theory, the topological B-model is constructed for the twistor string theory, of which the target space is the (super-)mini-twistor space. As the D = 4 twistor space can be considered as a fibration over D = 3 mini-twistor space, the dimensional reduction from D = 4 to D = 3 is conducted to obtain the scattering amplitudes for D = 3 super Yang-Mills theory. The result shows that, analogous to the D = 4 case, the twistor transformed D = 3 amplitudes are supported on holomorphic curves in the (super-)mini-twistor space. Another alternative twistor description---Berkovits's open string theory---is also analyzed. By the prescription which interrelates Witten's B-model and Berkovits's open string theory, the dimensional reduction can be made for Berkovits's model as well, in which the enhanced R-symmetry Spin(7) is recognized, whereas only the subgroup SU(4) is manifest in the B-model. The extension of the twistor string theory by adding mass terms is then proposed and

  8. Lectures on interacting string field theory

    International Nuclear Information System (INIS)

    Jevicki, A.

    1986-09-01

    We give a detailed review of the current formulations of interacting string field theory. The historical development of the subject is taken beginning with the old dual resonance model theory. The light cone approach is reviewed in some detail with emphasis on conformal mapping techniques. Witten's covariant approach is presented. The main body of the lectures concentrates on developing the operator formulation of Witten's theory. 38 refs., 22 figs., 5 tabs

  9. Dynamical symmetry breaking in quantum field theories

    CERN Document Server

    Miransky, Vladimir A

    1993-01-01

    The phenomenon of dynamical symmetry breaking (DSB) in quantum field theory is discussed in a detailed and comprehensive way. The deep connection between this phenomenon in condensed matter physics and particle physics is emphasized. The realizations of DSB in such realistic theories as quantum chromodynamics and electroweak theory are considered. Issues intimately connected with DSB such as critical phenomenona and effective lagrangian approach are also discussed.

  10. Recent progress in reggeon field theory

    International Nuclear Information System (INIS)

    Sugar, R.L.

    1977-01-01

    The present status of the pomeron theory in the reggeon field theory is summarized. For α 0 ( 0 -a bare intercept, αsub(oc) - a certain critical value) the theory is in a very good shape. It appears to satisfy both S and t-channel unitarity, and to avoid all of the decreases which plagued the simple pole model of the pomeron. For α 0 >αsub(oc) the situation is less clear

  11. Pure field theories and MACSYMA algorithms

    Science.gov (United States)

    Ament, W. S.

    1977-01-01

    A pure field theory attempts to describe physical phenomena through singularity-free solutions of field equations resulting from an action principle. The physics goes into forming the action principle and interpreting specific results. Algorithms for the intervening mathematical steps are sketched. Vacuum general relativity is a pure field theory, serving as model and providing checks for generalizations. The fields of general relativity are the 10 components of a symmetric Riemannian metric tensor; those of the Einstein-Straus generalization are the 16 components of a nonsymmetric. Algebraic properties are exploited in top level MACSYMA commands toward performing some of the algorithms of that generalization. The light cone for the theory as left by Einstein and Straus is found and simplifications of that theory are discussed.

  12. Axion topological field theory of topological superconductors

    Science.gov (United States)

    Qi, Xiao-Liang; Witten, Edward; Zhang, Shou-Cheng

    2013-04-01

    Topological superconductors are gapped superconductors with gapless and topologically robust quasiparticles propagating on the boundary. In this paper, we present a topological field theory description of three-dimensional time-reversal invariant topological superconductors. In our theory the topological superconductor is characterized by a topological coupling between the electromagnetic field and the superconducting phase fluctuation, which has the same form as the coupling of “axions” with an Abelian gauge field. As a physical consequence of our theory, we predict the level crossing induced by the crossing of special “chiral” vortex lines, which can be realized by considering s-wave superconductors in proximity with the topological superconductor. Our theory can also be generalized to the coupling with a gravitational field.

  13. An introduction to relativistic quantum field theory

    CERN Document Server

    Schweber, Silvan S

    1961-01-01

    Complete, systematic, and self-contained, this text introduces modern quantum field theory. "Combines thorough knowledge with a high degree of didactic ability and a delightful style." - Mathematical Reviews. 1961 edition.

  14. Quantum field theory with infinite component local fields as an alternative to the string theories

    International Nuclear Information System (INIS)

    Krasnikov, N.V.

    1987-05-01

    We show that the introduction of the infinite component local fields with higher order derivatives in the interaction makes the theory completely ultraviolet finite. For the γ 5 -anomalous theories the introduction of the infinite component field makes the theory renormalizable or superrenormalizable. (orig.)

  15. The conceptual basis of Quantum Field Theory

    NARCIS (Netherlands)

    Hooft, G. 't

    2005-01-01

    Relativistic Quantum Field Theory is a mathematical scheme to describe the sub-atomic particles and forces. The basic starting point is that the axioms of Special Relativity on the one hand and those of Quantum Mechanics on the other, should be combined into one theory. The fundamental

  16. Renormalizability of effective scalar field theory

    CERN Document Server

    Ball, R D

    1994-01-01

    We present a comprehensive discussion of the consistency of the effective quantum field theory of a single $Z_2$ symmetric scalar field. The theory is constructed from a bare Euclidean action which at a scale much greater than the particle's mass is constrained only by the most basic requirements; stability, finiteness, analyticity, naturalness, and global symmetry. We prove to all orders in perturbation theory the boundedness, convergence, and universality of the theory at low energy scales, and thus that the theory is perturbatively renormalizable in the sense that to a certain precision over a range of such scales it depends only on a finite number of parameters. We then demonstrate that the effective theory has a well defined unitary and causal analytic S--matrix at all energy scales. We also show that redundant terms in the Lagrangian may be systematically eliminated by field redefinitions without changing the S--matrix, and discuss the extent to which effective field theory and analytic S--matrix theory...

  17. Introductory lectures on quantum field theory

    International Nuclear Information System (INIS)

    Alvarez-Gaume, L.; Vasquez-Mozo, M.A.

    2011-01-01

    In these lectures we present a few topics in quantum field theory in detail. Some of them are conceptual and some more practical. They have been selected because they appear frequently in current applications to particle physics and string theory. (author)

  18. Klein Topological Field Theories from Group Representations

    Directory of Open Access Journals (Sweden)

    Sergey A. Loktev

    2011-07-01

    Full Text Available We show that any complex (respectively real representation of finite group naturally generates a open-closed (respectively Klein topological field theory over complex numbers. We relate the 1-point correlator for the projective plane in this theory with the Frobenius-Schur indicator on the representation. We relate any complex simple Klein TFT to a real division ring.

  19. Electromagnetic Field Theory A Collection of Problems

    CERN Document Server

    Mrozynski, Gerd

    2013-01-01

    After a brief introduction into the theory of electromagnetic fields and the definition of the field quantities the book teaches the analytical solution methods of Maxwell’s equations by means of several characteristic examples. The focus is on static and stationary electric and magnetic fields, quasi stationary fields, and electromagnetic waves. For a deeper understanding, the many depicted field patterns are very helpful. The book offers a collection of problems and solutions which enable the reader to understand and to apply Maxwell’s theory for a broad class of problems including classical static problems right up to waveguide eigenvalue problems. Content Maxwell’s Equations - Electrostatic Fields - Stationary Current Distributions – Magnetic Field of Stationary Currents – Quasi Stationary Fields: Eddy Currents - Electromagnetic Waves Target Groups Advanced Graduate Students in Electrical Engineering, Physics, and related Courses Engineers and Physicists Authors Professor Dr.-Ing. Gerd Mrozynski...

  20. Simple recursion relations for general field theories

    International Nuclear Information System (INIS)

    Cheung, Clifford; Shen, Chia-Hsien; Trnka, Jaroslav

    2015-01-01

    On-shell methods offer an alternative definition of quantum field theory at tree-level, replacing Feynman diagrams with recursion relations and interaction vertices with a handful of seed scattering amplitudes. In this paper we determine the simplest recursion relations needed to construct a general four-dimensional quantum field theory of massless particles. For this purpose we define a covering space of recursion relations which naturally generalizes all existing constructions, including those of BCFW and Risager. The validity of each recursion relation hinges on the large momentum behavior of an n-point scattering amplitude under an m-line momentum shift, which we determine solely from dimensional analysis, Lorentz invariance, and locality. We show that all amplitudes in a renormalizable theory are 5-line constructible. Amplitudes are 3-line constructible if an external particle carries spin or if the scalars in the theory carry equal charge under a global or gauge symmetry. Remarkably, this implies the 3-line constructibility of all gauge theories with fermions and complex scalars in arbitrary representations, all supersymmetric theories, and the standard model. Moreover, all amplitudes in non-renormalizable theories without derivative interactions are constructible; with derivative interactions, a subset of amplitudes is constructible. We illustrate our results with examples from both renormalizable and non-renormalizable theories. Our study demonstrates both the power and limitations of recursion relations as a self-contained formulation of quantum field theory.

  1. Classical theory of electric and magnetic fields

    CERN Document Server

    Good, Roland H

    1971-01-01

    Classical Theory of Electric and Magnetic Fields is a textbook on the principles of electricity and magnetism. This book discusses mathematical techniques, calculations, with examples of physical reasoning, that are generally applied in theoretical physics. This text reviews the classical theory of electric and magnetic fields, Maxwell's Equations, Lorentz Force, and Faraday's Law of Induction. The book also focuses on electrostatics and the general methods for solving electrostatic problems concerning images, inversion, complex variable, or separation of variables. The text also explains ma

  2. Unified-field theory: yesterday, today, tomorrow

    International Nuclear Information System (INIS)

    Bergman, P.G.

    1982-01-01

    Beginning with the expounding of Einstein understanding of advantages and disadvantages of general relativity theory, the authors proceed to consideration of what the complete unified theory have to be according to Einstein. The four theories which can be considered as ''unified'', namely weyl and Calutsa ones, worked out a half of century ago, and twistor twisting and supersymmetry theories, nowadays attracting attention, are briefly described and discussed. The authors come to a conclusion that achievements in elementary-particle physics have to affect any future theory, that this theory has to explain the principle contradictions between classical and quantum field theories, and that finally it can lead to change of the modern space-time model as a four-dimensional variety

  3. Quantum field theory in a semiotic perspective

    International Nuclear Information System (INIS)

    Dosch, H.G.

    2005-01-01

    Viewing physical theories as symbolic constructions came to the fore in the middle of the nineteenth century with the emancipation of the classical theory of the electromagnetic field from mechanics; most notably this happened through the work of Helmholtz, Hertz, Poincare, and later Weyl. The epistemological problems that nourished this development are today highlighted within quantum field theory. The present essay starts off with a concise and non-technical outline of the firmly based aspects of relativistic quantum field theory, i.e. the very successful description of subnuclear phenomena. The particular methods, by which these different aspects have to be accessed, then get described as distinct facets of quantum field theory. The authors show how these different facets vary with respect to the relation between quantum fields and associated particles. Thus, by emphasising the respective role of various basic concepts involved, the authors claim that only a very general epistemic approach can properly account for this diversity - an account they trace back to the philosophical writings of the aforementioned physicists and mathematicians. Finally, what they call their semiotic perspective on quantum field theory gets related to recent discussions within the philosophy of science and turns out to act as a counterbalance to, for instance, structural realism. (orig.)

  4. Quantum field theory in a semiotic perspective

    Energy Technology Data Exchange (ETDEWEB)

    Dosch, H.G. [Heidelberg Univ. (Germany). Inst. fuer Theoretische Physik; Mueller, V.F. [Technische Univ. Kaiserslautern (Germany). Fachbereich Physik; Sieroka, N. [Zurich Univ. (Switzerland)

    2005-07-01

    Viewing physical theories as symbolic constructions came to the fore in the middle of the nineteenth century with the emancipation of the classical theory of the electromagnetic field from mechanics; most notably this happened through the work of Helmholtz, Hertz, Poincare, and later Weyl. The epistemological problems that nourished this development are today highlighted within quantum field theory. The present essay starts off with a concise and non-technical outline of the firmly based aspects of relativistic quantum field theory, i.e. the very successful description of subnuclear phenomena. The particular methods, by which these different aspects have to be accessed, then get described as distinct facets of quantum field theory. The authors show how these different facets vary with respect to the relation between quantum fields and associated particles. Thus, by emphasising the respective role of various basic concepts involved, the authors claim that only a very general epistemic approach can properly account for this diversity - an account they trace back to the philosophical writings of the aforementioned physicists and mathematicians. Finally, what they call their semiotic perspective on quantum field theory gets related to recent discussions within the philosophy of science and turns out to act as a counterbalance to, for instance, structural realism. (orig.)

  5. Superstring field theory equivalence: Ramond sector

    International Nuclear Information System (INIS)

    Kroyter, Michael

    2009-01-01

    We prove that the finite gauge transformation of the Ramond sector of the modified cubic superstring field theory is ill-defined due to collisions of picture changing operators. Despite this problem we study to what extent could a bijective classical correspondence between this theory and the (presumably consistent) non-polynomial theory exist. We find that the classical equivalence between these two theories can almost be extended to the Ramond sector: We construct mappings between the string fields (NS and Ramond, including Chan-Paton factors and the various GSO sectors) of the two theories that send solutions to solutions in a way that respects the linearized gauge symmetries in both sides and keeps the action of the solutions invariant. The perturbative spectrum around equivalent solutions is also isomorphic. The problem with the cubic theory implies that the correspondence of the linearized gauge symmetries cannot be extended to a correspondence of the finite gauge symmetries. Hence, our equivalence is only formal, since it relates a consistent theory to an inconsistent one. Nonetheless, we believe that the fact that the equivalence formally works suggests that a consistent modification of the cubic theory exists. We construct a theory that can be considered as a first step towards a consistent RNS cubic theory.

  6. arXiv Gauge Backgrounds and Zero-Mode Counting in F-Theory

    CERN Document Server

    Bies, Martin; Weigand, Timo

    2017-11-14

    Computing the exact spectrum of charged massless matter is a crucial step towards understanding the effective field theory describing F-theory vacua in four dimensions. In this work we further develop a coherent framework to determine the charged massless matter in F-theory compactified on elliptic fourfolds, and demonstrate its application in a concrete example. The gauge background is represented, via duality with M-theory, by algebraic cycles modulo rational equivalence. Intersection theory within the Chow ring allows us to extract coherent sheaves on the base of the elliptic fibration whose cohomology groups encode the charged zero-mode spectrum. The dimensions of these cohomology groups are computed with the help of modern techniques from algebraic geometry, which we implement in the software gap. We exemplify this approach in models with an Abelian and non-Abelian gauge group and observe jumps in the exact massless spectrum as the complex structure moduli are varied. An extended mathematical appendix gi...

  7. Magnetic Catalysis in Graphene Effective Field Theory.

    Science.gov (United States)

    DeTar, Carleton; Winterowd, Christopher; Zafeiropoulos, Savvas

    2016-12-23

    We report on the first calculation of magnetic catalysis at zero temperature in a fully nonperturbative simulation of the graphene effective field theory. Using lattice gauge theory, a nonperturbative analysis of the theory of strongly interacting, massless, (2+1)-dimensional Dirac fermions in the presence of an external magnetic field is performed. We show that in the zero-temperature limit, a nonzero value for the chiral condensate is obtained which signals the spontaneous breaking of chiral symmetry. This result implies a nonzero value for the dynamical mass of the Dirac quasiparticle.

  8. Supersymmetric gauge theories, quantization of Mflat, and conformal field theory

    International Nuclear Information System (INIS)

    Teschner, J.; Vartanov, G.S.

    2013-02-01

    We propose a derivation of the correspondence between certain gauge theories with N=2 supersymmetry and conformal field theory discovered by Alday, Gaiotto and Tachikawa in the spirit of Seiberg-Witten theory. Based on certain results from the literature we argue that the quantum theory of the moduli spaces of flat SL(2,R)-connections represents a nonperturbative ''skeleton'' of the gauge theory, protected by supersymmetry. It follows that instanton partition functions can be characterized as solutions to a Riemann-Hilbert type problem. In order to solve it, we describe the quantization of the moduli spaces of flat connections explicitly in terms of two natural sets of Darboux coordinates. The kernel describing the relation between the two pictures represents the solution to the Riemann Hilbert problem, and is naturally identified with the Liouville conformal blocks.

  9. Infrared problems in field perturbation theory

    International Nuclear Information System (INIS)

    David, Francois.

    1982-12-01

    The work presented mainly covers questions related to the presence of ''infrared'' divergences in perturbation expansions of the Green functions of certain massless field theories. It is important to determine the mathematical status of perturbation expansions in field theory in order to define the region in which they are valid. Renormalization and the symmetry of a theory are important factors in infrared problems. The main object of this thesis resides in the mathematical techniques employed: integral representations of the Feynman amplitudes; methods for desingularization, regularization and dimensional renormalization. Nonlinear two dimensional space-time sigma models describing Goldstone's low energy boson dynamics associated with a breaking of continuous symmetry are studied. Random surface models are then investigated followed by infrared divergences in super-renormalizable theories. Finally, nonperturbation effects in massless theories are studied by expanding the two-dimensional nonlinear sigma model in 1/N [fr

  10. Towards the mathematics of quantum field theory

    CERN Document Server

    Paugam, Frédéric

    2014-01-01

    The aim of this book is to introduce mathematicians (and, in particular, graduate students) to the mathematical methods of theoretical and experimental quantum field theory, with an emphasis on coordinate-free presentations of the mathematical objects in play. This should in turn promote interaction between mathematicians and physicists by supplying a common and flexible language for the good of both communities, even if the mathematical one is the primary target. This reference work provides a coherent and complete mathematical toolbox for classical and quantum field theory, based on categorical and homotopical methods, representing an original contribution to the literature. The first part of the book introduces the mathematical methods needed to work with the physicists' spaces of fields, including parameterized and functional differential geometry, functorial analysis, and the homotopical geometric theory of non-linear partial differential equations, with applications to general gauge theories. The second...

  11. Gravitation Field Dynamics in Jeans Theory

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... Closed system of time equations for nonrelativistic gravitation field and hydrodynamic medium was obtained by taking into account binary correlations of the field, which is the generalization of Jeans theory. Distribution function of the systemwas built on the basis of the Bogolyubov reduced description ...

  12. Field theory of polar continua

    International Nuclear Information System (INIS)

    Heinz, C.

    1988-01-01

    A Lagrangian density in the polar space X 1+3+3 depending of the potentials and their derivativs and of the fluxes is introduced. The potentials are then the mechanical and electromagnetic potentials, the potentials of gravity and in the polar space X 1+3+3 the components of affine connection. The fluxes are essentially the tangential motors of the mechanical and electromagnetic world-lines multiplied with the density of mass and electric charge. The Hamilton principle gives, with the in variational calculus usual integrations by part, here done via the theorem of Gauss, the equations of motion and the field equations. The conditions of integrability for these equations are discussed. (author)

  13. Mean-field magnetohydrodynamics and dynamo theory

    CERN Document Server

    Krause, F

    2013-01-01

    Mean-Field Magnetohydrodynamics and Dynamo Theory provides a systematic introduction to mean-field magnetohydrodynamics and the dynamo theory, along with the results achieved. Topics covered include turbulence and large-scale structures; general properties of the turbulent electromotive force; homogeneity, isotropy, and mirror symmetry of turbulent fields; and turbulent electromotive force in the case of non-vanishing mean flow. The turbulent electromotive force in the case of rotational mean motion is also considered. This book is comprised of 17 chapters and opens with an overview of the gen

  14. Circuit complexity in quantum field theory

    Science.gov (United States)

    Jefferson, Robert A.; Myers, Robert C.

    2017-10-01

    Motivated by recent studies of holographic complexity, we examine the question of circuit complexity in quantum field theory. We provide a quantum circuit model for the preparation of Gaussian states, in particular the ground state, in a free scalar field theory for general dimensions. Applying the geometric approach of Nielsen to this quantum circuit model, the complexity of the state becomes the length of the shortest geodesic in the space of circuits. We compare the complexity of the ground state of the free scalar field to the analogous results from holographic complexity, and find some surprising similarities.

  15. Dark Matter, Elko Fields and Weinberg's Quantum Field Theory Formalism

    Science.gov (United States)

    Gillard, Adam; Martin, Benjamin

    2012-02-01

    The Elko quantum field was introduced by Ahluwalia and Grumiller, who proposed it as a candidate for dark matter. We study the Elko field in Wemberg's formalism for quantum field theory. We prove that if one takes the symmetry group to be the full Pomcaré group then the Elko field is not a quantum field in the sense of Weinberg. This confirms results of Ahluwalia, Lee and Schritt, who showed using a different approach that the Elko field does not transform covariantly under rotations and hence has a preferred axis.

  16. Coadjoint orbits and conformal field theory

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, IV, Washington [Univ. of California, Berkeley, CA (United States)

    1993-08-01

    This thesis is primarily a study of certain aspects of the geometric and algebraic structure of coadjoint orbit representations of infinite-dimensional Lie groups. The goal of this work is to use coadjoint orbit representations to construct conformal field theories, in a fashion analogous to the free-field constructions of conformal field theories. The new results which are presented in this thesis are as follows: First, an explicit set of formulae are derived giving an algebraic realization of coadjoint orbit representations in terms of differential operators acting on a polynomial Fock space. These representations are equivalent to dual Verma module representations. Next, intertwiners are explicitly constructed which allow the construction of resolutions for irreducible representations using these Fock space realizations. Finally, vertex operators between these irreducible representations are explicitly constructed as chain maps between the resolutions; these vertex operators allow the construction of rational conformal field theories according to an algebraic prescription.

  17. Knots, topology and quantum field theories

    International Nuclear Information System (INIS)

    Lusanna, L.

    1989-01-01

    The title of the workshop, Knots, Topology and Quantum Field Theory, accurate reflected the topics discussed. There have been important developments in mathematical and quantum field theory in the past few years, which had a large impact on physicist thinking. It is historically unusual and pleasing that these developments are taking place as a result of an intense interaction between mathematical physicists and mathematician. On the one hand, topological concepts and methods are playing an increasingly important lead to novel mathematical concepts: for instance, the study of quantum groups open a new chapter in the deformation theory of Lie algebras. These developments at present will lead to new insights into the theory of elementary particles and their interactions. In essence, the talks dealt with three, broadly defined areas of theoretical physics. One was topological quantum field theories, the other the problem of quantum groups and the third one certain aspects of more traditional field theories, such as, for instance, quantum gravity. These topics, however, are interrelated and the general theme of the workshop defies rigid classification; this was evident from the cross references to be found in almo all the talks

  18. Cutkosky rules for superstring field theory

    International Nuclear Information System (INIS)

    Pius, Roji; Sen, Ashoke

    2016-01-01

    Superstring field theory expresses the perturbative S-matrix of superstring theory as a sum of Feynman diagrams each of which is manifestly free from ultraviolet divergences. The interaction vertices fall off exponentially for large space-like external momenta making the ultraviolet finiteness property manifest, but blow up exponentially for large time-like external momenta making it impossible to take the integration contours for loop energies to lie along the real axis. This forces us to carry out the integrals over the loop energies by choosing appropriate contours in the complex plane whose ends go to infinity along the imaginary axis but which take complicated form in the interior navigating around the various poles of the propagators. We consider the general class of quantum field theories with this property and prove Cutkosky rules for the amplitudes to all orders in perturbation theory. Besides having applications to string field theory, these results also give an alternative derivation of Cutkosky rules in ordinary quantum field theories.

  19. Cutkosky rules for superstring field theory

    Energy Technology Data Exchange (ETDEWEB)

    Pius, Roji [Perimeter Institute for Theoretical Physics,Waterloo, ON N2L 2Y5 (Canada); Sen, Ashoke [Harish-Chandra Research Institute,Chhatnag Road, Jhusi, Allahabad 211019 (India)

    2016-10-06

    Superstring field theory expresses the perturbative S-matrix of superstring theory as a sum of Feynman diagrams each of which is manifestly free from ultraviolet divergences. The interaction vertices fall off exponentially for large space-like external momenta making the ultraviolet finiteness property manifest, but blow up exponentially for large time-like external momenta making it impossible to take the integration contours for loop energies to lie along the real axis. This forces us to carry out the integrals over the loop energies by choosing appropriate contours in the complex plane whose ends go to infinity along the imaginary axis but which take complicated form in the interior navigating around the various poles of the propagators. We consider the general class of quantum field theories with this property and prove Cutkosky rules for the amplitudes to all orders in perturbation theory. Besides having applications to string field theory, these results also give an alternative derivation of Cutkosky rules in ordinary quantum field theories.

  20. Experimental signature of scaling violation implied by field theories

    International Nuclear Information System (INIS)

    Tung, W.

    1975-01-01

    Renormalizable field theories are found to predict a surprisingly specific pattern of scaling violation in deep inelastic scattering. Comparison with experiments is discussed. The feasibility of distinguishing asymptotically free field theories from conventional field theories is evaluated