WorldWideScience

Sample records for tensor gauge field

  1. Tensor gauge condition and tensor field decomposition

    Science.gov (United States)

    Zhu, Ben-Chao; Chen, Xiang-Song

    2015-10-01

    We discuss various proposals of separating a tensor field into pure-gauge and gauge-invariant components. Such tensor field decomposition is intimately related to the effort of identifying the real gravitational degrees of freedom out of the metric tensor in Einstein’s general relativity. We show that as for a vector field, the tensor field decomposition has exact correspondence to and can be derived from the gauge-fixing approach. The complication for the tensor field, however, is that there are infinitely many complete gauge conditions in contrast to the uniqueness of Coulomb gauge for a vector field. The cause of such complication, as we reveal, is the emergence of a peculiar gauge-invariant pure-gauge construction for any gauge field of spin ≥ 2. We make an extensive exploration of the complete tensor gauge conditions and their corresponding tensor field decompositions, regarding mathematical structures, equations of motion for the fields and nonlinear properties. Apparently, no single choice is superior in all aspects, due to an awkward fact that no gauge-fixing can reduce a tensor field to be purely dynamical (i.e. transverse and traceless), as can the Coulomb gauge in a vector case.

  2. 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)

  3. Confinement through tensor gauge fields

    International Nuclear Information System (INIS)

    Salam, A.; Strathdee, J.

    1977-12-01

    Using the 0(3,2)-symmetric de Sitter solution of Einstein's equation describing a strongly interacting tensor field it is shown that hadronic bags confining quarks can be represented as de Sitter ''micro-universes'' with radii given 1/R 2 =lambdak 2 /6. Here k 2 and lambda are the strong coupling and the ''cosmological'' constant which apear in the Einstein equation used. Surprisingly the energy spectrum for the two-body hadronic states is the same as that for a harmonic oscillator potential, though the wave functions are completely different. The Einstein equation can be extended to include colour for the tensor fields

  4. Renormalization of nonabelian gauge theories with tensor matter fields

    International Nuclear Information System (INIS)

    Lemes, Vitor; Renan, Ricardo; Sorella, Silvio Paolo

    1996-03-01

    The renormalizability of a nonabelian model describing the coupling between antisymmetric second rank tensor matter fields and Yang-Mills gauge fields is discussed within the BRS algebraic framework. (author). 12 refs

  5. Extended pure Yang-Mills gauge theories with scalar and tensor gauge fields

    International Nuclear Information System (INIS)

    Gabrielli, E.

    1991-01-01

    The usual abelian gauge theory is extended to an interacting Yang-Mills-like theory containing vector, scalar and tensor gauge fields. These gauge fields are seen as components along the Clifford algebra basis of a gauge vector-spinorial field. Scalar fields φ naturally coupled to vector and tensor fields have been found, leading to a natural φ 4 coupling in the lagrangian. The full expression of the lagrangian for the euclidean version of the theory is given. (orig.)

  6. Non-Abelian tensor gauge fields and higher-spin extension of standard model

    International Nuclear Information System (INIS)

    Savvidy, G.

    2006-01-01

    We suggest an extension of the gauge principle which includes non-Abelian tensor gauge fields. The invariant Lagrangian is quadratic in the field strength tensors and describes interaction of charged tensor gauge bosons of arbitrary large integer spin 1,2,l. Non-Abelian tensor gauge fields can be viewed as a unique gauge field with values in the infinite-dimensional current algebra associated with compact Lie group. The full Lagrangian exhibits also enhanced local gauge invariance with double number of gauge parameters which allows to eliminate all negative norm states of the nonsymmetric second-rank tensor gauge field, which describes therefore two polarizations of helicity-two massless charged tensor gauge boson and the helicity-zero ''axion'' The geometrical interpretation of the enhanced gauge symmetry with double number of gauge parameters is not yet known. (Abstract Copyright [2006], Wiley Periodicals, Inc.)

  7. A Third-Rank Tensor Field Based on a U(1) Gauge Theory in Loop Space

    OpenAIRE

    Shinichi, DEGUCHI; Tadahito, NAKAJIMA; Department of Physics and Atomic Energy Research Institute College of Science and Technology; Department of Physics and Atomic Energy Research Institute College of Science and Technology

    1995-01-01

    We derive the Stueckelberg formalism extended to a third-rank tensor field from a U(1) gauge theory in loop space, the space of all loops in space-time. The third-rank tensor field is regarded as a constrained U(1) gauge field on the loop space.

  8. 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

  9. Antisymmetric tensor Zp gauge symmetries in field theory and string theory

    International Nuclear Information System (INIS)

    Berasaluce-González, Mikel; Ramírez, Guillermo; Uranga, Angel M.

    2014-01-01

    We consider discrete gauge symmetries in D dimensions arising as remnants of broken continuous gauge symmetries carried by general antisymmetric tensor fields, rather than by standard 1-forms. The lagrangian for such a general Z p gauge theory can be described in terms of a r-form gauge field made massive by a (r−1)-form, or other dual realizations, that we also discuss. The theory contains charged topological defects of different dimensionalities, generalizing the familiar charged particles and strings in D=4. We describe realizations in string theory compactifications with torsion cycles, or with background field strength fluxes. We also provide examples of non-abelian discrete groups, for which the group elements are associated with charged objects of different dimensionality

  10. 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.

  11. Gauge theories, duality relations and the tensor hierarchy

    NARCIS (Netherlands)

    Bergshoeff, Eric A.; Hartong, Jelle; Hohm, Olaf; Huebscher, Mechthild; Ortin, Tomas; Hübscher, Mechthild

    We compute the complete 3- and 4-dimensional tensor hierarchies, i.e. sets of p-form fields, with 1 We construct gauge-invariant actions that include all the fields in the tensor hierarchies. We elucidate the relation between the gauge transformations of the p-form fields in the action and those of

  12. Gauge theories, duality relations and the tensor hierarchy

    International Nuclear Information System (INIS)

    Bergshoeff, Eric A.; Hohm, Olaf; Hartong, Jelle; Huebscher, Mechthild; OrtIn, Tomas

    2009-01-01

    We compute the complete 3- and 4-dimensional tensor hierarchies, i.e. sets of p-form fields, with 1 ≤ p ≤ D, which realize an off-shell algebra of bosonic gauge transformations. We show how these tensor hierarchies can be put on-shell by introducing a set of duality relations, thereby introducing additional scalars and a metric tensor. These so-called duality hierarchies encode the equations of motion of the bosonic part of the most general gauged supergravity theories in those dimensions, including the (projected) scalar equations of motion. We construct gauge-invariant actions that include all the fields in the tensor hierarchies. We elucidate the relation between the gauge transformations of the p-form fields in the action and those of the same fields in the tensor hierarchy.

  13. 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

  14. Gauge fields

    International Nuclear Information System (INIS)

    Itzykson, C.

    1978-01-01

    In these notes the author provides some background on the theory of gauge fields, a subject of increasing popularity among particle physicists (and others). Detailed motivations and applications which are covered in the other lectures of this school are not presented. In particular the application to weak interactions is omitted by referring to the introduction given by J. Ilipoulos a year ago (CERN Report 76-11). The aim is rather to stress those aspects which suggest that gauge fields may play some role in a future theory of strong interactions. (Auth.)

  15. Gauge and non-gauge curvature tensor copies

    International Nuclear Information System (INIS)

    Srivastava, P.P.

    1982-10-01

    A procedure for constructing curvature tensor copies is discussed using the anholonomic geometrical framework. The corresponding geometries are compared and the notion of gauge copy is elucidated. An explicit calculation is also made. (author)

  16. Systematics of higher-spin gauge fields

    International Nuclear Information System (INIS)

    de Wit, B.; Freedman, D.Z.

    1980-01-01

    Free-field theories for symmetric tensor and tensor-spinor gauge fields have recently been obtained which describe massless particles of arbitrary integer or half-integer spin. An independent discussion of these field theories is given here, based on a hierarchy of generalized Christoffel symbols with simple gauge transformation properties. The necessity of certain constraints on gauge fields and parameters is easily seen. Wave equations and Lagrangians are expressed in terms of the Christoffel symbols, and the independent modes of the system are counted in covariant gauges. Minimal-coupling inconsistency and a combined system of higher-spin boson gauge fields interacting with relativistic particles is discussed

  17. Continuum gauge fields from lattice gauge fields

    International Nuclear Information System (INIS)

    Goeckeler, M.; Kronfeld, A.S.; Schierholz, G.; Wiese, U.J.

    1993-01-01

    On the lattice some of the salient features of pure gauge theories and of gauge theories with fermions in complex representations of the gauge group seem to be lost. These features can be recovered by considering part of the theory in the continuum. The prerequisite for that is the construction of continuum gauge fields from lattice gauge fields. Such a construction, which is gauge covariant and complies with geometrical constructions of the topological charge on the lattice, is given in this paper. The procedure is explicitly carried out in the U(1) theory in two dimensions, where it leads to simple results. (orig.)

  18. Aspects of the Antisymmetric Tensor Field

    Science.gov (United States)

    Lahiri, Amitabha

    1991-02-01

    With the possible exception of gravitation, fundamental interactions are generally described by theories of point particles interacting via massless gauge fields. Since the advent of string theories the picture of physical interaction has changed to accommodate one in which extended objects interact with each other. The generalization of the gauge theories to extended objects leads to theories of antisymmetric tensor fields. At scales corresponding to present-day laboratory experiments one expects to see only point particles, their interactions modified by the presence of antisymmetric tensor fields in the theory. Therefore, in order to establish the validity of any theory with antisymmetric tensor fields one needs to look for manifestations of these fields at low energies. The principal problem of gauge theories is the failure to provide a suitable explanation for the generation of masses for the fields in the theory. While there is a known mechanism (spontaneous symmetry breaking) for generating masses for both the matter fields and the gauge fields, the lack of experimental evidence in support of an elementary scalar field suggests that one look for alternative ways of generating masses for the fields. The interaction of gauge fields with an antisymmetric tensor field seems to be an attractive way of doing so, especially since all indications point to the possibility that there will be no remnant degrees of freedom. On the other hand the interaction of such a field with black holes suggest an independent way of verifying the existence of such fields. In this dissertation the origins of the antisymmetric tensor field are discussed in terms of string theory. The interaction of black holes with such a field is discussed next. The last chapter discusses the effects of an antisymmetric tensor field on quantum electrodynamics when the fields are minimally coupled.

  19. Derivation of the Finslerian gauge field equations

    International Nuclear Information System (INIS)

    Asanov, G.S.

    1984-01-01

    As is well known the simplest way of formulating the equations for the Yang-Mills gauge fields consists in taking the Lagrangian to be quadratic in the gauge tensor, whereas the application of such an approach to the gravitational field yields equations which are of essentially more complicated structure than the Einstein equations. On the other hand, in the gravitational field theory the Lagrangian can be constructed to be of forms which may be both quadratic and linear in the curvature tensor, whereas the latter possibility is absent in the current gauge field theories. In previous work it has been shown that the Finslerian structure of the space-time gives rise to certain gauge fields provided that the internal symmetries may be regarded as symmetries of a three-dimensional Riemannian space. Continuing this work we show that appropriate equations for these gauge fields can be formulated in both ways, namely on the basis of the quadratic Lagrangian or, if a relevant generalization of the Palatini method is applied, on the basis of a Lagrangian linear in the gauge field strength tensor. The latter possibility proves to result in equations which are similar to the Einstein equations, a distinction being that the Finslerian Cartan curvature tensor rather then the Riemann curvature tensor enters the equations. (author)

  20. Anomalous coupling of scalars to gauge fields

    Energy Technology Data Exchange (ETDEWEB)

    Brax, Philippe [CEA, IPhT, CNRS, URA 2306, Gif-sur-Yvette (France). Inst. de Physique Theorique; Burrage, Clare [Geneve Univ. (Switzerland). Dept. de Physique Theorique; Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Davis, Anne-Christine [Centre for Mathematical Sciences, Cambridge (United Kingdom). Dept. of Applied Mathematics and Theoretical Physics; Seery, David [Sussex Univ., Brighton (United Kingdom). Dept. of Physics and Astronomy; Weltman, Amanda [Cape Town Univ., Rondebosch (South Africa). Astronomy, Cosmology and Gravity Centre

    2010-10-15

    We study the transformation properties of a scalar-tensor theory, coupled to fermions, under the Weyl rescaling associated with a transition from the Jordan to the Einstein frame. We give a simple derivation of the corresponding modification to the gauge couplings. After changing frames, this gives rise to a direct coupling between the scalar and the gauge fields. (orig.)

  1. Anomalous coupling of scalars to gauge fields

    International Nuclear Information System (INIS)

    Brax, Philippe; Davis, Anne-Christine; Seery, David; Weltman, Amanda

    2010-10-01

    We study the transformation properties of a scalar-tensor theory, coupled to fermions, under the Weyl rescaling associated with a transition from the Jordan to the Einstein frame. We give a simple derivation of the corresponding modification to the gauge couplings. After changing frames, this gives rise to a direct coupling between the scalar and the gauge fields. (orig.)

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

    International Nuclear Information System (INIS)

    Barcelos Neto, J.; Cabo, A.; Silva, M.B.D.

    1995-08-01

    We obtain a non-Abelian version of a theory involving vector and tensor and tensor gauge fields interacting via a massive topological coupling, besides the nonminimum one. The new fact is that the non-Abelian theory is not reducible and Stuckelberg fields are introduced in order to compatibilize gauge invariance, nontrivial physical degrees of freedom and the limit of the Abelian case. (author). 9 refs

  3. Gauge field copies

    International Nuclear Information System (INIS)

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

    1979-01-01

    The construction of field strength copies without any gauge constraint is discussed. Several examples are given, one of which is not only a field strength copy but also (at the same time) a 'current copy'. (author) [pt

  4. Gauge field models

    International Nuclear Information System (INIS)

    Becchi, C.; Rouet, A.; Stora, R.

    1975-10-01

    Stora's analysis is continued in discussing the nonabelian (Yang-Mills) gauge field models (G.F.M.). The gauge independence of the physical scattering operator is discussed in some details and the connection between its unitary and the Slavnov symmetry outlined. Only the models involving semisimple gauge groups are considered. This greatly simplifies the analysis of the possible quantum corrections to the Quantum Action Principle which is reduced to the study of the cohomology group of the Lie algebra characterizing the gauge theory. The discussion is at the classical level for the algebraic properties of the SU(2) Higgs-Kibble-Englert-Brout-Faddeev-Popov lagrangian and its invariance under Slavnov identity transformations is exhibited. The renormalization of the Slavnov identity in the G.M.F. involving semisimple gauge groups is studied. The unitary and gauge independence of the physical S operator in the SU(2) H.K. model is dealt with [fr

  5. Gauge fields in a torsion field

    International Nuclear Information System (INIS)

    Rosu, Ion

    2004-01-01

    In this paper we analyse the motion and the field equations in a non-null curvature and torsion space. In this 4-n dimensional space, the connection coefficients are γ bc a = 1/2S bc a + 1/2T bc a, where S bc a is the symmetrical part and T bc a are the components of the torsion tensor. We will consider that all the fields depend on x = x α , α = 1,2,3,4 and do not depend on y = y k , k=1,2,...,n. The factor S bc a depends on the components of the metric tensor g αβ (x) and on the gauge fields A ν s 0 (x) and the components of the torsion depend only on the gauge fields A ν s 0 (x). We take into consideration the particular case for which the geodesic equations coincide with the motion equations in the presence of the gravitational and the gauge fields. In this case the field equations are Einstein equations in a 4-n dimensional space. We show that both the geodesic equations and the field equations can be obtained from a variational principle. (author)

  6. Gauge field theories

    International Nuclear Information System (INIS)

    Leite Lopes, J.

    1981-01-01

    The book is intended to explain, in an elementary way, the basic notions and principles of gauge theories. Attention is centred on the Salem-Weinberg model of electro-weak interactions, as well as neutrino-lepton scattering and the parton model. Classical field theory, electromagnetic, Yang-Mills and gravitational gauge fields, weak interactions, Higgs mechanism and the SU(5) model of grand unification are also discussed. (U.K.)

  7. On behaviour of Weyl's gauge field

    International Nuclear Information System (INIS)

    Yuan Zhong Zhang.

    1990-05-01

    We consider a system, consisting of a metric tensor g μυ , a scalar field φ, a Weyl's gauge field A μ and a scalar matter field Φ, which is invariant under general coordinate transformation and Weyl's gauge transformation. Two kinds of identities and field equations are given and discussed. A special space-time with g μυ =φ -2 η μυ is considered in a gauge-independent manner. We point out that in a correct treatment where g μυ is not regarded as an independent variable, an auxiliary condition for Weyl's gauge field cannot be obtained. Therefore Weyl's gauge field can be treated as a usual field of positive norm. (author). 11 refs

  8. The geomagnetic field gradient tensor

    DEFF Research Database (Denmark)

    Kotsiaros, Stavros; Olsen, Nils

    2012-01-01

    We develop the general mathematical basis for space magnetic gradiometry in spherical coordinates. The magnetic gradient tensor is a second rank tensor consisting of 3 × 3 = 9 spatial derivatives. Since the geomagnetic field vector B is always solenoidal (∇ · B = 0) there are only eight independent...... tensor elements. Furthermore, in current free regions the magnetic gradient tensor becomes symmetric, further reducing the number of independent elements to five. In that case B is a Laplacian potential field and the gradient tensor can be expressed in series of spherical harmonics. We present properties...... of the magnetic gradient tensor and provide explicit expressions of its elements in terms of spherical harmonics. Finally we discuss the benefit of using gradient measurements for exploring the Earth’s magnetic field from space, in particular the advantage of the various tensor elements for a better determination...

  9. Magnetoelasticity as a gauge field

    International Nuclear Information System (INIS)

    Zorawski, Marek

    1987-01-01

    The goal of the paper is to formulate such a system in such a metric space that the geodesics of the space give the movement equations with the influence of electromagnetic forces. Local fields (stress) should be, of course, also included in the movement equations. For the geometrical structure of energy-momentum tensor, the known Einstein equation is adopted. It is also supposed that the Bianchi identities hold. Then in Riemannian space a non-holonomic system of reference is introduced, and the anholonomity object is associated to the electromagnetic field, as a gauge field. The considered theory is the classical one, it is not difficult to extend it to quantum field theory. (Auth.)

  10. Supersymmetric gauge field theories

    International Nuclear Information System (INIS)

    Slavnov, A.A.

    1976-01-01

    The paper is dealing with the role of supersymmetric gauge theories in the quantum field theory. Methods of manipulating the theories as well as possibilities of their application in elementary particle physics are presented. In particular, the necessity is explained of a theory in which there is symmetry between Fermi and Bose fields, in other words, of the supersymmetric gauge theory for construction of a scheme for the Higgs particle connecting parameters of scalar mesons with those of the rest fields. The mechanism of supersymmetry breaking is discussed which makes it possible to remain the symmetric procedure of renormalization intact. The above mechanism of spontaneous symmetry breaking is applied to demonstrate possibilities of constructing models of weak and electromagnetic interactions which would be acceptable from the point of view of experiments. It is noted that the supersymmetric gauge theories represent a natural technique for description of vector-like models

  11. Chiral primordial blue tensor spectra from the axion-gauge couplings

    Energy Technology Data Exchange (ETDEWEB)

    Obata, Ippei, E-mail: obata@tap.scphys.kyoto-u.ac.jp [Department of Physics, Kyoto University, Kyoto, 606-8502 (Japan)

    2017-06-01

    We suggest the new feature of primordial gravitational waves sourced by the axion-gauge couplings, whose forms are motivated by the dimensional reduction of the form field in the string theory. In our inflationary model, as an inflaton we adopt two types of axion, dubbed the model-independent axion and the model-dependent axion, which couple with two gauge groups with different sign combination each other. Due to these forms both polarization modes of gauge fields are amplified and enhance both helicies of tensor modes during inflation. We point out the possibility that a primordial blue-tilted tensor power spectra with small chirality are provided by the combination of these axion-gauge couplings, intriguingly both amplitudes and chirality are potentially testable by future space-based gravitational wave interferometers such as DECIGO and BBO project.

  12. Quantized gauge field

    International Nuclear Information System (INIS)

    Arodz, H.

    1987-01-01

    The two formulations of quantum theory of the free electromagnetic field are presented. In the Coulomb gauge approach the independent dynamical variables have been identified and then, in order to quantize the theory, it has been sufficient to apply the straightforward canonical quantization. In the Gupta-Bleuler approach the auxilliary theory is first considered. The straightforward canonical quantization of it leads to the quantum theory defined in the space G with indefinite norm. 15 refs. (author)

  13. 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

  14. Gauge field theories

    International Nuclear Information System (INIS)

    Pokorski, S.

    1987-01-01

    Quantum field theory forms the present theoretical framework for the understanding of the fundamental interactions of particle physics. This book examines gauge theories and their symmetries with an emphasis on their physical and technical aspects. The author discusses field-theoretical techniques and encourages the reader to perform many of the calculations presented. This book includes a brief introduction to perturbation theory, the renormalization programme, and the use of the renormalization group equation. Several topics of current research interest are covered, including chiral symmetry and its breaking, anomalies, and low energy effective lagrangians and some basics of supersymmetry

  15. Gauge field vacuum structure in geometrical aspect

    International Nuclear Information System (INIS)

    Konopleva, N.P.

    2003-01-01

    Vacuum conception is one of the main conceptions of quantum field theory. Its meaning in classical field theory is also very profound. In this case the vacuum conception is closely connected with ideas of the space-time geometry. The global and local geometrical space-time conceptions lead to different vacuum definitions and therefore to different ways of physical theory construction. Some aspects of the gauge field vacuum structure are analyzed. It is shown that in the gauge field theory the vacuum Einstein equation solutions describe the relativistic vacuum as common vacuum of all gauge fields and its sources. Instantons (both usual and hyperbolical) are regarded as nongravitating matter, because they have zero energy-momentum tensors and correspond to vacuum Einstein equations

  16. Gauge fields and inflation

    Science.gov (United States)

    Maleknejad, A.; Sheikh-Jabbari, M. M.; Soda, J.

    2013-07-01

    The isotropy and homogeneity of the cosmic microwave background (CMB) favors “scalar driven” early Universe inflationary models. However, gauge fields and other non-scalar fields are far more common at all energy scales, in particular at high energies seemingly relevant to inflation models. Hence, in this review we consider the role and consequences, theoretical and observational, that gauge fields can have during the inflationary era. Gauge fields may be turned on in the background during inflation, or may become relevant at the level of cosmic perturbations. There have been two main classes of models with gauge fields in the background, models which show violation of the cosmic no-hair theorem and those which lead to isotropic FLRW cosmology, respecting the cosmic no-hair theorem. Models in which gauge fields are only turned on at the cosmic perturbation level, may source primordial magnetic fields. We also review specific observational features of these models on the CMB and/or the primordial cosmic magnetic fields. Our discussions will be mainly focused on the inflation period, with only a brief discussion on the post inflationary (p)reheating era. Large field models: The initial value of the inflaton field is large, generically super-Planckian, and it rolls slowly down toward the potential minimum at smaller φ values. For instance, chaotic inflation is one of the representative models of this class. The typical potential of large-field models has a monomial form as V(φ)=V0φn. A simple analysis using the dynamical equations reveals that for number of e-folds Ne larger than 60, we require super-Planckian initial field values,5φ0>3M. For these models typically ɛ˜η˜Ne-1. Small field models: Inflaton field is initially small and slowly evolves toward the potential minimum at larger φ values. The small field models are characterized by the following potential V(φ)=V0(1-(), which corresponds to a Taylor expansion about the origin, but more realistic

  17. Gravitating SO (3,1) gauge field

    International Nuclear Information System (INIS)

    Aragone, C.; Restuccia, A.

    1978-01-01

    In this article, we postulate SO (3,1) as a local symmetry of any relativistic theory. This is equivalent to assuming the existence of a gauge field associated with this noncompact group. This SO (3,1) gauge field is the spinorial affinity which usually appears when we deal with weighting spinors, which, as is well known, cannot be coupled to the metric tensor field. Furthermore, according to the integral approach to gauge fields proposed by Yang, it is also recognized that in order to obtain models of gravity we have to introduce ordinary affinities as the gauge field associated with GL (4) (the local symmetry determined by the parallel transport). Thus if we assume both GL (4) and SO (3,1) as local independent symmetries we are led to analyze the dynamical gauge system constituted by the Einstein field interacting with the SO (3,1) Weyl--Yang gauge field. We think this system is a possible model of strong gravity. Once we give the first-order action for this Einstein--Weyl--Yang system we study whether the SO (3,1) gauge field could have a tetrad associated with it. It is also shown that both fields propagate along a unique characteristic cone. Algebraic and differential constraints are solved when the system evolves along a null coordinate. The unconstrained expression for the action of the system is found working in the Bondi gauge. That allows us to exhibit an explicit expression of the dynamical generator of the system. Its signature turns out to be nondefinite, due to the nondefinite contribution of the Weyl--Yang field, which has the typical spinorial behavior. A conjecture is made that such an unpleasant feature could be overcome in the quantized version of this model

  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. Emergent Abelian Gauge Fields from Noncommutative Gravity

    Directory of Open Access Journals (Sweden)

    Allen Stern

    2010-02-01

    Full Text Available We construct exact solutions to noncommutative gravity following the formulation of Chamseddine and show that they are in general accompanied by Abelian gauge fields which are first order in the noncommutative scale. This provides a mechanism for generating cosmological electromagnetic fields in an expanding space-time background, and also leads to multipole-like fields surrounding black holes. Exact solutions to noncommutative Einstein-Maxwell theory can give rise to first order corrections to the metric tensor, as well as to the electromagnetic fields. This leads to first order shifts in the horizons of charged black holes.

  20. The gauge-invariant canonical energy-momentum tensor

    Science.gov (United States)

    Lorcé, Cédric

    2016-03-01

    The canonical energy-momentum tensor is often considered as a purely academic object because of its gauge dependence. However, it has recently been realized that canonical quantities can in fact be defined in a gauge-invariant way provided that strict locality is abandoned, the non-local aspect being dictacted in high-energy physics by the factorization theorems. Using the general techniques for the parametrization of non-local parton correlators, we provide for the first time a complete parametrization of the energy-momentum tensor (generalizing the purely local parametrizations of Ji and Bakker-Leader-Trueman used for the kinetic energy-momentum tensor) and identify explicitly the parts accessible from measurable two-parton distribution functions (TMDs and GPDs). As by-products, we confirm the absence of model-independent relations between TMDs and parton orbital angular momentum, recover in a much simpler way the Burkardt sum rule and derive three similar new sum rules expressing the conservation of transverse momentum.

  1. The gauge-invariant canonical energy-momentum tensor

    International Nuclear Information System (INIS)

    Lorce, C.

    2016-01-01

    The canonical energy-momentum tensor is often considered as a purely academic object because of its gauge dependence. However, it has recently been realized that canonical quantities can in fact be defined in a gauge-invariant way provided that strict locality is abandoned, the non-local aspect being dictated in high-energy physics by the factorization theorems. Using the general techniques for the parametrization of non-local parton correlators, we provide for the first time a complete parametrization of the energy-momentum tensor (generalizing the purely local parametrizations of Ji and Bakker-Leader-Trueman used for the kinetic energy-momentum tensor) and identify explicitly the parts accessible from measurable two-parton distribution functions (TMD and GPD). As by-products, we confirm the absence of model-independent relations between TMDs and parton orbital angular momentum, recover in a much simpler way the Burkardt sum rule and derive 3 similar new sum rules expressing the conservation of transverse momentum. (author)

  2. The topology of gauge fields

    International Nuclear Information System (INIS)

    Tellis, D.R.

    2000-01-01

    Full text: Instantons in pure Yang-Mills gauge theory have been studied extensively by physicists and mathematicians alike. The surprisingly rich topological structure plays an important role in hadron structure. A crucial role is played by how the boundary conditions on the gauge fields are imposed. While the topology of gauge fields in pure Yang-Mills gauge theory is understood for the compact manifold of the 4-sphere, the manifold of the 4-torus remains an active area of study. The latter is particularly important in the study of Lattice QCD

  3. Gauge-invariant Yang-Mills fields and the role of Lorentz gauge condition

    International Nuclear Information System (INIS)

    Skachkov, N.B.; Shevchenko, O.Yu.

    1985-01-01

    A new class of gauge-invariant (G.I.) fields is constructed. The inversion formulae that express these fields through the G.I. strength tensor are obtained. It is shown that for the G.I. fields the Lorentz gauge condition appears as the secondary constraint. These fields coincide with the usual ones in some definite gauges. The Dyson-Schwinger equations for the G.I. spinor propagator are derived. It is found that in QED this propagator has a simple pole singularity (p-m) -1 in the infrared limit

  4. Model of unified gauge fields

    International Nuclear Information System (INIS)

    Leite Lopes, J.

    1998-04-01

    In this work, we discuss the physical ideas which represents the basis for the unified gauge field model. Despite of the difficulties that we presently have for embodying in a natural manner muons and hadrons in that model, we have the feeling that we are on the way which seems to lead to the construction of a theory in which the Maxwell electromagnetic field and the Fermi weak interaction field are manifestations of a unique subjacent physical entity - the unified gauge fields. (author)

  5. Gauge invariance of string fields

    International Nuclear Information System (INIS)

    Banks, T.; Peskin, M.E.

    1985-10-01

    Some work done to understand the appearance of gauge bosons and gravitons in string theories is reported. An action has been constructed for free (bosonic) string field theory which is invariant under an infinite set of gauge transformations which include Yang-Mills transformations and general coordinate transformations as special cases. 15 refs., 1 tab

  6. 'Baldin autumn' and gauge fields

    International Nuclear Information System (INIS)

    Konopleva, N.P.

    2008-01-01

    The paper is the reminiscences of the participant of the gauge field theory beginning and the first 'Baldin Autumn' conference in 1969. This conference was named 'Vector Mesons and Electromagnetic Interactions'. At that time, just the processes with vector mesons participation contained some experimental indications of new universal interactions existence. Vector dominance was the experimental evidence of physical reasons of the gauge field theory. In the course of time the gauge field theory form, which was under discussion thirty seven years ago, became generally recognized and experimentally corroborated. It led to construction of the well-known Standard Model of elementary particle interactions

  7. Non-Abelian gauge fields in two spatial dimensions

    International Nuclear Information System (INIS)

    Hagen, C.R.

    1987-01-01

    Generalizing an earlier work on the Abelian case the most general non-Abelian gauge theory in two spatial dimensions is derived. It is shown that local gauge invariance leads to a new term in the action which in turn requires that the gauge current operator have a part which is bilinear in the non-Abelian gauge field-strength tensor. Although a radiation (or axial) gauge quantization is possible, this approach is found not to yield the maximal set of commutation relations among the basic fields. The latter goal can be accomplished only by a rather unusual gauge choice which has not previously been studied. Quantization conditions on the coupling constant implied by invariance under large gauge transformations are also derived

  8. Antisymmetric tensor generalizations of affine vector fields.

    Science.gov (United States)

    Houri, Tsuyoshi; Morisawa, Yoshiyuki; Tomoda, Kentaro

    2016-02-01

    Tensor generalizations of affine vector fields called symmetric and antisymmetric affine tensor fields are discussed as symmetry of spacetimes. We review the properties of the symmetric ones, which have been studied in earlier works, and investigate the properties of the antisymmetric ones, which are the main theme in this paper. It is shown that antisymmetric affine tensor fields are closely related to one-lower-rank antisymmetric tensor fields which are parallelly transported along geodesics. It is also shown that the number of linear independent rank- p antisymmetric affine tensor fields in n -dimensions is bounded by ( n + 1)!/ p !( n - p )!. We also derive the integrability conditions for antisymmetric affine tensor fields. Using the integrability conditions, we discuss the existence of antisymmetric affine tensor fields on various spacetimes.

  9. Massive and massless gauge fields of any spin and symmetry

    International Nuclear Information System (INIS)

    Hussain, F.; Jarvis, P.D.

    1988-05-01

    An analysis of the BRST approach to massive and massless gauge fields of any spin and symmetry is presented. Previous results on massless gauge fields are extended to totally antisymmetric massless tensors and Kaehler-Dirac particles. Two methods for arriving at a BRST invariant, massive theory from the corresponding massless one are discussed. The first allows for an interpretation in terms of dimensional reduction, while the second keeps the BRST operator of the massless theory, but employs gauge invariant fields. (author). 10 refs

  10. Towards a unified picture for gauge and Higgs fields

    International Nuclear Information System (INIS)

    Mecklenburg, W.

    1981-01-01

    A scheme for a geometrical unification of gauge and Higgs fields, previously given for SU 2 , is generalized to include arbitrary semisimple gauge groups. Gauge and physical Higgs fields appear as different components of the same tensor in a high dimensional manifold, the higher dimensions being comprised by the group coordinates. Their respective inhomogeneous transformation behaviour is derived from the same principle. The number of Higgs fields is restricted. The form of the Higgs potential is fixed and the mass of the Higgs particle is predicted in terms of the vector boson mass. (author)

  11. Decorated tensor network renormalization for lattice gauge theories and spin foam models

    International Nuclear Information System (INIS)

    Dittrich, Bianca; Mizera, Sebastian; Steinhaus, Sebastian

    2016-01-01

    Tensor network techniques have proved to be powerful tools that can be employed to explore the large scale dynamics of lattice systems. Nonetheless, the redundancy of degrees of freedom in lattice gauge theories (and related models) poses a challenge for standard tensor network algorithms. We accommodate for such systems by introducing an additional structure decorating the tensor network. This allows to explicitly preserve the gauge symmetry of the system under coarse graining and straightforwardly interpret the fixed point tensors. We propose and test (for models with finite Abelian groups) a coarse graining algorithm for lattice gauge theories based on decorated tensor networks. We also point out that decorated tensor networks are applicable to other models as well, where they provide the advantage to give immediate access to certain expectation values and correlation functions. (paper)

  12. Decorated tensor network renormalization for lattice gauge theories and spin foam models

    Science.gov (United States)

    Dittrich, Bianca; Mizera, Sebastian; Steinhaus, Sebastian

    2016-05-01

    Tensor network techniques have proved to be powerful tools that can be employed to explore the large scale dynamics of lattice systems. Nonetheless, the redundancy of degrees of freedom in lattice gauge theories (and related models) poses a challenge for standard tensor network algorithms. We accommodate for such systems by introducing an additional structure decorating the tensor network. This allows to explicitly preserve the gauge symmetry of the system under coarse graining and straightforwardly interpret the fixed point tensors. We propose and test (for models with finite Abelian groups) a coarse graining algorithm for lattice gauge theories based on decorated tensor networks. We also point out that decorated tensor networks are applicable to other models as well, where they provide the advantage to give immediate access to certain expectation values and correlation functions.

  13. twistors and gauge fields

    Directory of Open Access Journals (Sweden)

    A. G. Sergeev

    1986-01-01

    Full Text Available We describe briefly the basic ideas and results of the twistor theory. The main points: twistor representation of Minkowsky space, Penrose correspondence and its geometrical properties, twistor interpretation of linear massless fields, Yang-Mills fields (including instantons and monopoles and Einstein-Hilbert equations.

  14. Renormalization of gauge fields models

    International Nuclear Information System (INIS)

    Becchi, C.; Rouet, A.; Stora, R.

    1974-01-01

    A new approach to gauge field models is described. It is based on the Bogoliubov-Parasiuk-Hepp-Zimmermann (BPHZ) renormalization scheme making extensive use of the quantum action principle, and the Slavnov invariance. The quantum action principle being first summarized in the framework of the BPHZ is then applied to a global symmetry problem. The symmetry property of the gauge field Lagrangians in the tree approximation is exhibited, and the preservation of this property at the quantum level is discussed. The main results relative to the Abelian and SU(2) Higgs-Kibble models are briefly reviewed [fr

  15. The Topology of Symmetric Tensor Fields

    Science.gov (United States)

    Levin, Yingmei; Batra, Rajesh; Hesselink, Lambertus; Levy, Yuval

    1997-01-01

    Combinatorial topology, also known as "rubber sheet geometry", has extensive applications in geometry and analysis, many of which result from connections with the theory of differential equations. A link between topology and differential equations is vector fields. Recent developments in scientific visualization have shown that vector fields also play an important role in the analysis of second-order tensor fields. A second-order tensor field can be transformed into its eigensystem, namely, eigenvalues and their associated eigenvectors without loss of information content. Eigenvectors behave in a similar fashion to ordinary vectors with even simpler topological structures due to their sign indeterminacy. Incorporating information about eigenvectors and eigenvalues in a display technique known as hyperstreamlines reveals the structure of a tensor field. The simplify and often complex tensor field and to capture its important features, the tensor is decomposed into an isotopic tensor and a deviator. A tensor field and its deviator share the same set of eigenvectors, and therefore they have a similar topological structure. A a deviator determines the properties of a tensor field, while the isotopic part provides a uniform bias. Degenerate points are basic constituents of tensor fields. In 2-D tensor fields, there are only two types of degenerate points; while in 3-D, the degenerate points can be characterized in a Q'-R' plane. Compressible and incompressible flows share similar topological feature due to the similarity of their deviators. In the case of the deformation tensor, the singularities of its deviator represent the area of vortex core in the field. In turbulent flows, the similarities and differences of the topology of the deformation and the Reynolds stress tensors reveal that the basic addie-viscosity assuptions have their validity in turbulence modeling under certain conditions.

  16. Introduction to gauge field theory

    International Nuclear Information System (INIS)

    Bailin, D.; Love, A.

    1986-01-01

    This book provides a postgraduate level introduction to gauge field theory entirely from a path integral standpoint without any reliance on the more traditional method of canonical quantisation. The ideas are developed by quantising the self-interacting scalar field theory, and are then used to deal with all the gauge field theories relevant to particle physics, quantum electrodynamics, quantum chromodynamics, electroweak theory, grand unified theories, and field theories at non-zero temperature. The use of these theories to make precise experimental predictions requires the development of the renormalised theories. This book provides a knowledge of relativistic quantum mechanics, but not of quantum field theory. The topics covered form a foundation for a knowledge of modern relativistic quantum field theory, providing a comprehensive coverage with emphasis on the details of actual calculations rather than the phenomenology of the applications

  17. Gauge invariant fractional electromagnetic fields

    International Nuclear Information System (INIS)

    Lazo, Matheus Jatkoske

    2011-01-01

    Fractional derivatives and integrations of non-integers orders was introduced more than three centuries ago but only recently gained more attention due to its application on nonlocal phenomenas. In this context, several formulations of fractional electromagnetic fields was proposed, but all these theories suffer from the absence of an effective fractional vector calculus, and in general are non-causal or spatially asymmetric. In order to deal with these difficulties, we propose a spatially symmetric and causal gauge invariant fractional electromagnetic field from a Lagrangian formulation. From our fractional Maxwell's fields arose a definition for the fractional gradient, divergent and curl operators. -- Highlights: → We propose a fractional Lagrangian formulation for fractional Maxwell's fields. → We obtain gauge invariant fractional electromagnetic fields. → Our generalized fractional Maxwell's field is spatially symmetrical. → We discuss the non-causality of the theory.

  18. Gauge invariant fractional electromagnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Lazo, Matheus Jatkoske, E-mail: matheuslazo@furg.br [Instituto de Matematica, Estatistica e Fisica - FURG, Rio Grande, RS (Brazil)

    2011-09-26

    Fractional derivatives and integrations of non-integers orders was introduced more than three centuries ago but only recently gained more attention due to its application on nonlocal phenomenas. In this context, several formulations of fractional electromagnetic fields was proposed, but all these theories suffer from the absence of an effective fractional vector calculus, and in general are non-causal or spatially asymmetric. In order to deal with these difficulties, we propose a spatially symmetric and causal gauge invariant fractional electromagnetic field from a Lagrangian formulation. From our fractional Maxwell's fields arose a definition for the fractional gradient, divergent and curl operators. -- Highlights: → We propose a fractional Lagrangian formulation for fractional Maxwell's fields. → We obtain gauge invariant fractional electromagnetic fields. → Our generalized fractional Maxwell's field is spatially symmetrical. → We discuss the non-causality of the theory.

  19. 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

  20. 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.)

  1. Seamless warping of diffusion tensor fields

    DEFF Research Database (Denmark)

    Xu, Dongrong; Hao, Xuejun; Bansal, Ravi

    2008-01-01

    To warp diffusion tensor fields accurately, tensors must be reoriented in the space to which the tensors are warped based on both the local deformation field and the orientation of the underlying fibers in the original image. Existing algorithms for warping tensors typically use forward mapping...... of seams, including voxels in which the deformation is extensive. Backward mapping, however, cannot reorient tensors in the template space because information about the directional orientation of fiber tracts is contained in the original, unwarped imaging space only, and backward mapping alone cannot...... transfer that information to the template space. To combine the advantages of forward and backward mapping, we propose a novel method for the spatial normalization of diffusion tensor (DT) fields that uses a bijection (a bidirectional mapping with one-to-one correspondences between image spaces) to warp DT...

  2. On gauge fields with sources

    International Nuclear Information System (INIS)

    Torres del Castillo, G.F.; Departamento de Fisica, Centro de Investigacion y de Estudios Avanzados del IPN, Apartado Postal 14-740, 07000 Mexico, D. F., Mexico)

    1987-01-01

    It is shown that in an algebraically special space-time that admits a congruence of null strings, the Yang--Mills equations with sources reduce to a pair of nonlinear first-order differential equations for two matrices, provided that the gauge field is aligned with the congruence. In the case where the current is tangent to the null strings, the gauge field is determined by a matrix potential that has to satisfy a second-order differential equation with quadratic nonlinearities. As an example of this case, the Yang--Mills--Weyl equations are reduced, assuming that the multiplet of Weyl neutrino fields are also aligned with the congruence, and a reduced form of the Einstein--Yang--Mills--Weyl equations is also given

  3. On the equivalence among stress tensors in a gauge-fluid system

    Science.gov (United States)

    Mitra, Arpan Krishna; Banerjee, Rabin; Ghosh, Subir

    2017-12-01

    In this paper, we bring out the subtleties involved in the study of a first-order relativistic field theory with auxiliary field variables playing an essential role. In particular, we discuss the nonisentropic Eulerian (or Hamiltonian) fluid model. Interactions are introduced by coupling the fluid to a dynamical Maxwell (U(1)) gauge field. This dynamical nature of the gauge field is crucial in showing the equivalence, on the physical subspace, of the stress tensor derived from two definitions, i.e. the canonical (Noether) one and the symmetric one. In the conventional equal-time formalism, we have shown that the generators of the space-time transformations obtained from these two definitions agree modulo the Gauss constraint. This equivalence in the physical sector has been achieved only because of the dynamical nature of the gauge fields. Subsequently, we have explicitly demonstrated the validity of the Schwinger condition. A detailed analysis of the model in lightcone formalism has also been done where several interesting features are revealed.

  4. Non-Abelian gauge fields

    Science.gov (United States)

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

    2013-07-01

    Building a universal quantum computer is a central goal of emerging quantum technologies, which has the potential to revolutionize science and technology. Unfortunately, this future does not seem to be very close at hand. However, quantum computers built for a special purpose, i.e. quantum simulators , are currently developed in many leading laboratories. Many schemes for quantum simulation have been proposed and realized using, e.g., ultracold atoms in optical lattices, ultracold trapped ions, atoms in arrays of cavities, atoms/ions in arrays of traps, quantum dots, photonic networks, or superconducting circuits. The progress in experimental implementations is more than spectacular. Particularly interesting are those systems that simulate quantum matter evolving in the presence of gauge fields. In the quantum simulation framework, the generated (synthetic) gauge fields may be Abelian, in which case they are the direct analogues of the vector potentials commonly associated with magnetic fields. In condensed matter physics, strong magnetic fields lead to a plethora of fascinating phenomena, among which the most paradigmatic is perhaps the quantum Hall effect. The standard Hall effect consists in the appearance of a transverse current, when a longitudinal voltage difference is applied to a conducting sample. For quasi-two-dimensional semiconductors at low temperatures placed in very strong magnetic fields, the transverse conductivity, the ratio between the transverse current and the applied voltage, exhibits perfect and robust quantization, independent for instance of the material or of its geometry. Such an integer quantum Hall effect, is now understood as a deep consequence of underlying topological order. Although such a system is an insulator in the bulk, it supports topologically robust edge excitations which carry the Hall current. The robustness of these chiral excitations against backscattering explains the universality of the quantum Hall effect. Another

  5. arXiv Tensor to scalar ratio from single field magnetogenesis

    CERN Document Server

    Giovannini, Massimo

    2017-08-10

    The tensor to scalar ratio is affected by the evolution of the large-scale gauge fields potentially amplified during an inflationary stage of expansion. After deriving the exact evolution equations for the scalar and tensor modes of the geometry in the presence of dynamical gauge fields, it is shown that the tensor to scalar ratio is bounded from below by the dominance of the adiabatic contribution and it cannot be smaller than one thousands whenever the magnetogenesis is driven by a single inflaton field.

  6. Gauge invariant fractional electromagnetic fields

    Science.gov (United States)

    Lazo, Matheus Jatkoske

    2011-09-01

    Fractional derivatives and integrations of non-integers orders was introduced more than three centuries ago but only recently gained more attention due to its application on nonlocal phenomenas. In this context, several formulations of fractional electromagnetic fields was proposed, but all these theories suffer from the absence of an effective fractional vector calculus, and in general are non-causal or spatially asymmetric. In order to deal with these difficulties, we propose a spatially symmetric and causal gauge invariant fractional electromagnetic field from a Lagrangian formulation. From our fractional Maxwell's fields arose a definition for the fractional gradient, divergent and curl operators.

  7. 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.

  8. Conformal field theories and tensor categories. Proceedings

    International Nuclear Information System (INIS)

    Bai, Chengming; Fuchs, Juergen; Huang, Yi-Zhi; Kong, Liang; Runkel, Ingo; Schweigert, Christoph

    2014-01-01

    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.

  9. Real-Time Dynamics in U(1 Lattice Gauge Theories with Tensor Networks

    Directory of Open Access Journals (Sweden)

    T. Pichler

    2016-03-01

    Full Text Available Tensor network algorithms provide a suitable route for tackling real-time-dependent problems in lattice gauge theories, enabling the investigation of out-of-equilibrium dynamics. We analyze a U(1 lattice gauge theory in (1+1 dimensions in the presence of dynamical matter for different mass and electric-field couplings, a theory akin to quantum electrodynamics in one dimension, which displays string breaking: The confining string between charges can spontaneously break during quench experiments, giving rise to charge-anticharge pairs according to the Schwinger mechanism. We study the real-time spreading of excitations in the system by means of electric-field and particle fluctuations. We determine a dynamical state diagram for string breaking and quantitatively evaluate the time scales for mass production. We also show that the time evolution of the quantum correlations can be detected via bipartite von Neumann entropies, thus demonstrating that the Schwinger mechanism is tightly linked to entanglement spreading. To present a variety of possible applications of this simulation platform, we show how one could follow the real-time scattering processes between mesons and the creation of entanglement during scattering processes. Finally, we test the quality of quantum simulations of these dynamics, quantifying the role of possible imperfections in cold atoms, trapped ions, and superconducting circuit systems. Our results demonstrate how entanglement properties can be used to deepen our understanding of basic phenomena in the real-time dynamics of gauge theories such as string breaking and collisions.

  10. Contemporary status of gauge fields

    International Nuclear Information System (INIS)

    Slavnov, A.A.

    1979-01-01

    A successive and a self-consistent scheme of calculation is developed for the Yang-Mills theory. Boundary conditions related to the problem on the physical vacuum are predetermined for solving the field theory equations. It is noted that the principal problem for the Yang-Mills theory consists in finding the actual ground state. The role of instantons in constructing the gauge field ground state and of the dynamic mechanism of quark confinement are also discussed. An assumption has been made that the Yang-Mills theory can be solved exactly. This assumption is based on analogy between the Yang-Mills theory and the two-dimensional nonlinear σ-model. An exceptionality of the Yang-Mills theory is stressed which consists in the fact that it is a unique massless vector field theory in which no patologies are observed connected with nonpositive determination of energy

  11. Adding gauge fields to Kaplan's fermions

    International Nuclear Information System (INIS)

    Blum, T.; Kaerkkaeinen, L.

    1994-01-01

    We experiment with adding dynamical gauge field to Kaplan (defect) fermions. In the case of U(1) gauge theory we use an inhomogeneous Higgs mechanism to restrict the 3d gauge dynamics to a planar 2d defect. In our simulations the 3d theory produce the correct 2d gauge dynamics. We measure fermion propagators with dynamical gauge fields. They posses the correct chiral structure. The fermions at the boundary of the support of the gauge field (waveguide) are non-chiral, and have a mass two times heavier than the chiral modes. Moreover, these modes cannot be excited by a source at the defect; implying that they are dynamically decoupled. We have also checked that the anomaly relation is fullfilled for the case of a smooth external gauge field. (orig.)

  12. Classical confining solutions of a tensor gauge theory incorporating colour

    International Nuclear Information System (INIS)

    Salam, A.; Strathdee, J.

    1977-04-01

    A mass-modified Einstein-Weyl gauge theory of colour carrying spin-two mesons is formulated. A classical solution is exhibited for the case of internal SU(2) symmetry which may confine quarks in colour singlets

  13. (Ln-bar, g)-spaces. Special tensor fields

    International Nuclear Information System (INIS)

    Manoff, S.; Dimitrov, B.

    1998-01-01

    The Kronecker tensor field, the contraction tensor field, as well as the multi-Kronecker and multi-contraction tensor fields are determined and the action of the covariant differential operator, the Lie differential operator, the curvature operator, and the deviation operator on these tensor fields is established. The commutation relations between the operators Sym and Asym and the covariant and Lie differential operators are considered acting on symmetric and antisymmetric tensor fields over (L n bar, g)-spaces

  14. Gauge field condensation in geometric quantum chromodynamics

    International Nuclear Information System (INIS)

    Guendelman, E.I.

    1991-09-01

    In odd number of dimensions, it is possible to construct general covariant gauge theories, where the metric is not an independent variable, but local function of the gauge fields. Starting from standardly defined gauge theory, upon functional integration of some variables, we could end up with such moodels. For models with SU(2) and SU(3) symmetry in three dimensions, gauge field condensation take place in the vacuum, which is nevertheless homogeneous and isotropic up to a gauge transformation, provided the space is flat. Introducing Higgs fields that spontaneously break the gauge symmetry, we get a breakdown of the homogenity and isotropy of the vacuum. Finally, we discuss how some of this ideas can be generalized to four and other even dimensions. (author)

  15. Measurability of non-abelium gauge fields

    Energy Technology Data Exchange (ETDEWEB)

    Ivanenko, D.D.; Obukhov, Yu.N.

    New estimations of the accuracy of measurement of non-abeliar gauge field components are obtained on the base of qualitative analysis of the test body equations of motion. They generalize the Bohr and Rosenfeld results on the measurability of an electomagnetic field for the case of an arbitrary gauge group.

  16. The light-front gauge-invariant energy-momentum tensor

    International Nuclear Information System (INIS)

    Lorce, Cedric

    2015-01-01

    In this study, we provide for the first time a complete parametrization for the matrix elements of the generic asymmetric, non-local and gauge-invariant canonical energy-momentum tensor, generalizing therefore former works on the symmetric, local and gauge-invariant kinetic energy-momentum tensor also known as the Belinfante-Rosenfeld energy-momentum tensor. We discuss in detail the various constraints imposed by non-locality, linear and angular momentum conservation. We also derive the relations with two-parton generalized and transverse-momentum dependent distributions, clarifying what can be learned from the latter. In particular, we show explicitly that two-parton transverse-momentum dependent distributions cannot provide any model-independent information about the parton orbital angular momentum. On the way, we recover the Burkardt sum rule and obtain similar new sum rules for higher-twist distributions

  17. Visualization and processing of tensor fields

    CERN Document Server

    Weickert, Joachim

    2007-01-01

    Presents information on the visualization and processing of tensor fields. This book serves as an overview for the inquiring scientist, as a basic foundation for developers and practitioners, and as a textbook for specialized classes and seminars for graduate and doctoral students.

  18. From stochastic completion fields to tensor voting

    NARCIS (Netherlands)

    Almsick, van M.A.; Duits, R.; Franken, E.M.; Haar Romenij, ter B.M.; Olsen, O.F.; Florack, L.M.J.; Kuijper, A.

    2005-01-01

    Several image processing algorithms imitate the lateral interaction of neurons in the visual striate cortex V1 to account for the correlations along contours and lines. Here we focus on two methodologies: tensor voting by Guy and Medioni, and stochastic completion fields by Mumford, Williams and

  19. Stress-energy tensors for vector fields outside a static black hole

    International Nuclear Information System (INIS)

    Barrios, F.A.; Vaz, C.

    1989-01-01

    We obtain new, approximate stress-energy tensors to describe gauge fields in the neighborhood of a Schwarzschild black hole. We assume that the coefficient of ∇ 2 R in the trace anomaly is correctly given by ζ-function regularization. Our approximation differs from that of Page and of Brown and Ottewill and relies upon a new, improved ansatz for the form of the stress-energy tensor in the ultrastatic optical metric of the black hole. The Israel-Hartle-Hawking thermal tensor is constructed to be regular on the horizon and possess the correct asymptotic behavior. Our approximation of Unruh's tensor is likewise constructed to be regular on the future horizon and exhibit a luminosity which agrees with Page's numerically obtained value. Geometric expressions for the approximate tensors are given, and the approximate energy density of the thermal tensor on the horizon is compared with recent numerical estimates

  20. Relativistic particles with spin and antisymmetric tensor fields

    International Nuclear Information System (INIS)

    Sandoval Junior, L.

    1990-09-01

    A study is made on antisymmetric tensor fields particularly on second order tensor field as far as his equivalence to other fields and quantization through the path integral are concerned. Also, a particle model is studied which has been recently proposed and reveals to be equivalent to antisymmetric tensor fields of any order. (L.C.J.A.)

  1. Wormholes, emergent gauge fields, and the weak gravity conjecture

    Energy Technology Data Exchange (ETDEWEB)

    Harlow, Daniel [Center for the Fundamental Laws of Nature, Physics Department, Harvard University,Cambridge MA, 02138 (United States)

    2016-01-20

    This paper revisits the question of reconstructing bulk gauge fields as boundary operators in AdS/CFT. In the presence of the wormhole dual to the thermofield double state of two CFTs, the existence of bulk gauge fields is in some tension with the microscopic tensor factorization of the Hilbert space. I explain how this tension can be resolved by splitting the gauge field into charged constituents, and I argue that this leads to a new argument for the “principle of completeness”, which states that the charge lattice of a gauge theory coupled to gravity must be fully populated. I also claim that it leads to a new motivation for (and a clarification of) the “weak gravity conjecture”, which I interpret as a strengthening of this principle. This setup gives a simple example of a situation where describing low-energy bulk physics in CFT language requires knowledge of high-energy bulk physics. This contradicts to some extent the notion of “effective conformal field theory”, but in fact is an expected feature of the resolution of the black hole information problem. An analogous factorization issue exists also for the gravitational field, and I comment on several of its implications for reconstructing black hole interiors and the emergence of spacetime more generally.

  2. Energy-momentum tensor of intermediate vector bosons in an external electromagnetic field

    International Nuclear Information System (INIS)

    Mostepanenko, V.M.; Sokolov, I.Yu.

    1988-01-01

    Expressions are obtained for the canonical and metric energy-momentum tensors of the vector field of intermediate bosons in an external electromagnetic field. It is shown that in the case of a gyromagnetic ratio not equal to unity the energy-momentum tensor cannot be symmetrized on its indices, and an additional term proportional to the anomalous magnetic moment appears in the conservation laws. A modification of the canonical formalism for scalar and vector fields in an external field is proposed in accordance with which the Hamiltonian density is equal to the 00 component of the energy-momentum tensor. An expression for the energy-momentum tensor of a closed system containing a gauge field of intermediate bosons and an electromagnetic field is obtained

  3. Constraints on Gauge Field Production during Inflation

    DEFF Research Database (Denmark)

    Nurmi, Sami; Sloth, Martin Snoager

    2014-01-01

    In order to gain new insights into the gauge field couplings in the early universe, we consider the constraints on gauge field production during inflation imposed by requiring that their effect on the CMB anisotropies are subdominant. In particular, we calculate systematically the bispectrum...... of the primordial curvature perturbation induced by the presence of vector gauge fields during inflation. Using a model independent parametrization in terms of magnetic non-linearity parameters, we calculate for the first time the contribution to the bispectrum from the cross correlation between the inflaton...

  4. Correlation functions of the energy-momentum tensor in SU(2) gauge theory at finite temperature

    DEFF Research Database (Denmark)

    Huebner, K.; Karsch, F.; Pica, Claudio

    2008-01-01

    We calculate correlation functions of the energy-momentum tensor in the vicinity of the deconfinement phase transition of (3+1)-dimensional SU(2) gauge theory and discuss their critical behavior in the vicinity of the second order deconfinement transition. We show that correlation functions...... of the trace of the energy momentum tensor diverge uniformly at the critical point in proportion to the specific heat singularity. Correlation functions of the pressure, on the other hand, stay finite at the critical point. We discuss the consequences of these findings for the analysis of transport...... coefficients, in particular the bulk viscosity, in the vicinity of a second order phase transition point....

  5. Elastic Gauge Fields in Weyl Semimetals

    Science.gov (United States)

    Cortijo, Alberto; Ferreiros, Yago; Landsteiner, Karl; Hernandez Vozmediano, Maria Angeles

    We show that, as it happens in graphene, elastic deformations couple to the electronic degrees of freedom as pseudo gauge fields in Weyl semimetals. We derive the form of the elastic gauge fields in a tight-binding model hosting Weyl nodes and see that this vector electron-phonon coupling is chiral, providing an example of axial gauge fields in three dimensions. As an example of the new response functions that arise associated to these elastic gauge fields, we derive a non-zero phonon Hall viscosity for the neutral system at zero temperature. The axial nature of the fields provides a test of the chiral anomaly in high energy with three axial vector couplings. European Union structural funds and the Comunidad de Madrid MAD2D-CM Program (S2013/MIT-3007).

  6. Gauge fields in nonlinear group realizations involving two-dimensional space-time symmetry

    International Nuclear Information System (INIS)

    Machacek, M.E.; McCliment, E.R.

    1975-01-01

    It is shown that gauge fields may be consistently introduced into a model Lagrangian previously considered by the authors. The model is suggested by the spontaneous breaking of a Lorentz-type group into a quasiphysical two-dimensional space-time and one internal degree of freedom, loosely associated with charge. The introduction of zero-mass gauge fields makes possible the absorption via the Higgs mechanism of the Goldstone fields that appear in the model despite the fact that the Goldstone fields do not transform as scalars. Specifically, gauge invariance of the Yang-Mills type requires the introduction of two sets of massless gauge fields. The transformation properties in two-dimensional space-time suggest that one set is analogous to a charge doublet that behaves like a second-rank tensor in real four-dimensional space time. The other set suggests a spin-one-like charge triplet. Via the Higgs mechanism, the first set absorbs the Goldstone fields and acquires mass. The second set remains massless. If massive gauge fields are introduced, the associated currents are not conserved and the Higgs mechanism is no longer fully operative. The Goldstone fields are not eliminated, but coupling between the Goldstone fields and the gauge fields does shift the mass of the antisymmetric second-rank-tensor gauge field components

  7. 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.

  8. World-sheet gauge fields in superstrings

    International Nuclear Information System (INIS)

    Porrati, M.; Tomboulis, E.T.

    1989-01-01

    We investigate the introduction of world-sheet 2-dimensional gauge fields in a manner consistent with world-sheet supersymmetry. We obtain the effective string action resulting from the exact integration over the world-sheet gauge fields to show that it generally describes string models with spontaneous breaking of gauge symmetries with continuous breaking parameters. We examine the question of spacetime supersymmetry spontaneous breaking, and show that breaking with continuous, in particular arbitrarily small breaking parameters does not occur; only breaking for discrete values of parameters is possible. (orig.)

  9. Scalar potential for the gauged Heisenberg algebra and a non-polynomial antisymmetric tensor theory

    International Nuclear Information System (INIS)

    D'Auria, R.; Ferrara, S.; Trigiante, M.; Vaula, S.

    2005-01-01

    We study some issues related to the effective theory of Calabi-Yau compactifications with fluxes in type II theories. At first the scalar potential for a generic electric Abelian gauging of the Heisenberg algebra, underlying all possible gaugings of R-R isometries, is presented and shown to exhibit, in some circumstances, a 'dual' no-scale structure under the interchange of hypermultiplets and vector multiplets. Subsequently a new setting of such theories, when all R-R scalars are dualized into antisymmetric tensors, is discussed. This formulation falls in the class of non-polynomial tensor theories considered long ago by Freedman and Townsend and it may be relevant for the introduction of both electric and magnetic charges

  10. Gauge bridges in classical field theory

    International Nuclear Information System (INIS)

    Jakobs, S.

    2009-03-01

    In this thesis Poisson structures of two classical gauge field theories (Maxwell-Klein-Gordon- and Maxwell-Dirac-system) are constructed using the parametrix construction of Green's functions. Parametrices for the Maxwell-Klein-Gordon- and Maxwell-Dirac-system are constructed in Minkowski space and this construction is later generalized to curved space times for the Maxwell-Klein-Gordon-system. With these Green's functions Poisson brackets will be defined as Peierls brackets. Finally non-local, gauge invariant observables, the so-called ''gauge bridges''are constructed. Gauge bridges are the matrix elements of holonomy operators. It is shown, that these emerge from Poisson brackets of local, gauge invariant observables. (orig.)

  11. Globally conformal invariant gauge field theory with rational correlation functions

    CERN Document Server

    Nikolov, N M; Todorov, I T; CERN. Geneva; Todorov, Ivan T.

    2003-01-01

    Operator product expansions (OPE) for the product of a scalar field with its conjugate are presented as infinite sums of bilocal fields $V_{\\kappa} (x_1, x_2)$ of dimension $(\\kappa, \\kappa)$. For a {\\it globally conformal invariant} (GCI) theory we write down the OPE of $V_{\\kappa}$ into a series of {\\it twist} (dimension minus rank) $2\\kappa$ symmetric traceless tensor fields with coefficients computed from the (rational) 4-point function of the scalar field. We argue that the theory of a GCI hermitian scalar field ${\\cal L} (x)$ of dimension 4 in $D = 4$ Minkowski space such that the 3-point functions of a pair of ${\\cal L}$'s and a scalar field of dimension 2 or 4 vanish can be interpreted as the theory of local observables of a conformally invariant fixed point in a gauge theory with Lagrangian density ${\\cal L} (x)$.

  12. Group theory and lattice gauge fields

    International Nuclear Information System (INIS)

    Creutz, M.

    1988-09-01

    Lattice gauge theory, formulated in terms of invariant integrals over group elements on lattice bonds, benefits from many group theoretical notions. Gauge invariance provides an enormous symmetry and powerful constraints on expectation values. Strong coupling expansions require invariant integrals over polynomials in group elements, all of which can be evaluated by symmetry considerations. Numerical simulations involve random walks over the group. These walks automatically generate the invariant group measure, avoiding explicit parameterization. A recently proposed overrelaxation algorithm is particularly efficient at exploring the group manifold. These and other applications of group theory to lattice gauge fields are reviewed in this talk. 17 refs

  13. Emergent Gauge Fields in Holographic Superconductors

    CERN Document Server

    Domènech, Oriol; Pomarol, Alex; Salvio, Alberto; Silva, Pedro J

    2010-01-01

    Holographic superconductors have been studied so far in the absence of dynamical electromagnetic fields, namely in the limit in which they coincide with holographic superfluids. It is possible, however, to introduce dynamical gauge fields if a Neumann-type boundary condition is imposed on the AdS-boundary. In 3+1 dimensions, the dual theory is a 2+1 dimensional CFT whose spectrum contains a massless gauge field, signaling the emergence of a gauge symmetry. We study the impact of a dynamical gauge field in vortex configurations where it is known to significantly affect the energetics and phase transitions. We calculate the critical magnetic fields H_c1 and H_c2, obtaining that holographic superconductors are of Type II (H_c1 < H_c2). We extend the study to 4+1 dimensions where the gauge field does not appear as an emergent phenomena, but can be introduced, by a proper renormalization, as an external dynamical field. We also compare our predictions with those arising from a Ginzburg-Landau theory and identif...

  14. Vacuum Polarization Tensor for QED in the Light Front Gauge

    International Nuclear Information System (INIS)

    Suzuki, A.T.; Soriano, L.A.; Bolzan, J.D.; Sales, J.H.O.

    2012-01-01

    The use of light front coordinates in quantum field theories (QFT) always brought some problems and controversies. In this work we explore some aspects of its formalism with respect to the employment of dimensional regularization in the computation of the photon's self-energy at the one-loop level and how the fermion propagator has an important role in the outcoming results. (author)

  15. Energy-momentum tensor for a Casimir apparatus in a weak gravitational field

    International Nuclear Information System (INIS)

    Bimonte, Giuseppe; Calloni, Enrico; Esposito, Giampiero; Rosa, Luigi

    2006-01-01

    The influence of the gravity acceleration on the regularized energy-momentum tensor of the quantized electromagnetic field between two plane-parallel conducting plates is derived. We use Fermi coordinates and work to first order in the constant acceleration parameter. A perturbative expansion, to this order, of the Green functions involved and of the energy-momentum tensor is derived by means of the covariant geodesic point-splitting procedure. In correspondence to the Green functions satisfying mixed and gauge-invariant boundary conditions, and Ward identities, the energy-momentum tensor is covariantly conserved and satisfies the expected relation between gauge-breaking and ghost parts, while a new simple formula for the trace anomaly is obtained to first order in the constant acceleration. A more systematic derivation is therefore obtained of the theoretical prediction according to which the Casimir device in a weak gravitational field will experience a tiny push in the upwards direction

  16. Gauge field theories an introduction with applications

    CERN Document Server

    Guidry, Mike

    1991-01-01

    Acquaints readers with the main concepts and literature of elementary particle physics and quantum field theory. In particular, the book is concerned with the elaboration of gauge field theories in nuclear physics; the possibility of creating fundamental new states of matter such as an extended quark-gluon plasma in ultra-relativistic heavy ion collisions; and the relation of gauge theories to the creation and evolution of the universe. Divided into three parts, it opens with an introduction to the general principles of relativistic quantum field theory followed by the essential ingredients of gauge fields for weak and electromagnetic interactions, quantum chromodynamics and strong interactions. The third part is concerned with the interface between modern elementary particle physics and "applied disciplines" such as nuclear physics, astrophysics and cosmology. Includes references and numerous exercises

  17. Vacuum in intensive gauge fields

    International Nuclear Information System (INIS)

    Matinian, S.G.

    1977-12-01

    The behaviour of vacuum in a covariantly constant Yang-Mills field is considered. The expressions for the effective Lagrangian in an intensive field representing the asymptotic freedom of the theory are found

  18. Feature Surfaces in Symmetric Tensor Fields Based on Eigenvalue Manifold.

    Science.gov (United States)

    Palacios, Jonathan; Yeh, Harry; Wang, Wenping; Zhang, Yue; Laramee, Robert S; Sharma, Ritesh; Schultz, Thomas; Zhang, Eugene

    2016-03-01

    Three-dimensional symmetric tensor fields have a wide range of applications in solid and fluid mechanics. Recent advances in the (topological) analysis of 3D symmetric tensor fields focus on degenerate tensors which form curves. In this paper, we introduce a number of feature surfaces, such as neutral surfaces and traceless surfaces, into tensor field analysis, based on the notion of eigenvalue manifold. Neutral surfaces are the boundary between linear tensors and planar tensors, and the traceless surfaces are the boundary between tensors of positive traces and those of negative traces. Degenerate curves, neutral surfaces, and traceless surfaces together form a partition of the eigenvalue manifold, which provides a more complete tensor field analysis than degenerate curves alone. We also extract and visualize the isosurfaces of tensor modes, tensor isotropy, and tensor magnitude, which we have found useful for domain applications in fluid and solid mechanics. Extracting neutral and traceless surfaces using the Marching Tetrahedra method can cause the loss of geometric and topological details, which can lead to false physical interpretation. To robustly extract neutral surfaces and traceless surfaces, we develop a polynomial description of them which enables us to borrow techniques from algebraic surface extraction, a topic well-researched by the computer-aided design (CAD) community as well as the algebraic geometry community. In addition, we adapt the surface extraction technique, called A-patches, to improve the speed of finding degenerate curves. Finally, we apply our analysis to data from solid and fluid mechanics as well as scalar field analysis.

  19. The Topology of Three-Dimensional Symmetric Tensor Fields

    Science.gov (United States)

    Lavin, Yingmei; Levy, Yuval; Hesselink, Lambertus

    1994-01-01

    We study the topology of 3-D symmetric tensor fields. The goal is to represent their complex structure by a simple set of carefully chosen points and lines analogous to vector field topology. The basic constituents of tensor topology are the degenerate points, or points where eigenvalues are equal to each other. First, we introduce a new method for locating 3-D degenerate points. We then extract the topological skeletons of the eigenvector fields and use them for a compact, comprehensive description of the tensor field. Finally, we demonstrate the use of tensor field topology for the interpretation of the two-force Boussinesq problem.

  20. Hamiltonian quantization of self-dual tensor fields and a bosonic Nielsen-Ninomiya theorem

    International Nuclear Information System (INIS)

    Tang Waikeung

    1989-01-01

    The quantization of self-dual tensor fields is carried out following the procedure of Batalin and Fradkin. The (anti) self-duality constraints (either fermionic or bosonic) in the action leads to the gravitational anomaly. In the process of gauge fixing, the impossibility of the co-existence of a positive hamiltonian and covariant action is shown. A version of the Nielsen-Ninomiya theorem applies to self-dual tensor fields viz. the lattice version of the theory shows species doubling with zero net chirality. (orig.)

  1. Glyph-Based Comparative Visualization for Diffusion Tensor Fields.

    Science.gov (United States)

    Zhang, Changgong; Schultz, Thomas; Lawonn, Kai; Eisemann, Elmar; Vilanova, Anna

    2016-01-01

    Diffusion Tensor Imaging (DTI) is a magnetic resonance imaging modality that enables the in-vivo reconstruction and visualization of fibrous structures. To inspect the local and individual diffusion tensors, glyph-based visualizations are commonly used since they are able to effectively convey full aspects of the diffusion tensor. For several applications it is necessary to compare tensor fields, e.g., to study the effects of acquisition parameters, or to investigate the influence of pathologies on white matter structures. This comparison is commonly done by extracting scalar information out of the tensor fields and then comparing these scalar fields, which leads to a loss of information. If the glyph representation is kept, simple juxtaposition or superposition can be used. However, neither facilitates the identification and interpretation of the differences between the tensor fields. Inspired by the checkerboard style visualization and the superquadric tensor glyph, we design a new glyph to locally visualize differences between two diffusion tensors by combining juxtaposition and explicit encoding. Because tensor scale, anisotropy type, and orientation are related to anatomical information relevant for DTI applications, we focus on visualizing tensor differences in these three aspects. As demonstrated in a user study, our new glyph design allows users to efficiently and effectively identify the tensor differences. We also apply our new glyphs to investigate the differences between DTI datasets of the human brain in two different contexts using different b-values, and to compare datasets from a healthy and HIV-infected subject.

  2. Novel symmetries in Weyl-invariant gravity with massive gauge field

    Energy Technology Data Exchange (ETDEWEB)

    Abhinav, K. [S.N. Bose National Centre for Basic Sciences, Salt Lake, Kolkata (India); Shukla, A.; Panigrahi, P.K. [Indian Institute of Science Education and Research Kolkata, Mohanpur (India)

    2016-11-15

    The background field method is used to linearize the Weyl-invariant scalar-tensor gravity, coupled with a Stueckelberg field. For a generic background metric, this action is found not to be invariant, under both a diffeomorphism and generalized Weyl symmetry, the latter being a combination of gauge and Weyl transformations. Interestingly, the quadratic Lagrangian, emerging from a background of Minkowski metric, respects both transformations independently. The Becchi-Rouet-Stora-Tyutin symmetry of scalar-tensor gravity coupled with a Stueckelberg-like massive gauge particle, possessing a diffeomorphism and generalized Weyl symmetry, reveals that in both cases negative-norm states with unphysical degrees of freedom do exist. We then show that, by combining diffeomorphism and generalized Weyl symmetries, all the ghost states decouple, thereby removing the unphysical redundancies of the theory. During this process, the scalar field does not represent any dynamic mode, yet modifies the usual harmonic gauge condition through non-minimal coupling with gravity. (orig.)

  3. Hairy black hole solutions in U(1) gauge-invariant scalar-vector-tensor theories

    Science.gov (United States)

    Heisenberg, Lavinia; Tsujikawa, Shinji

    2018-05-01

    In U (1) gauge-invariant scalar-vector-tensor theories with second-order equations of motion, we study the properties of black holes (BH) on a static and spherically symmetric background. In shift-symmetric theories invariant under the shift of scalar ϕ → ϕ + c, we show the existence of new hairy BH solutions where a cubic-order scalar-vector interaction gives rise to a scalar hair manifesting itself around the event horizon. In the presence of a quartic-order interaction besides the cubic coupling, there are also regular BH solutions endowed with scalar and vector hairs.

  4. Energy-momentum tensor of the electromagnetic field

    International Nuclear Information System (INIS)

    Horndeski, G.W.; Wainwright, J.

    1977-01-01

    In this paper we investigate the energy-momentum tensor of the most general second-order vector-tensor theory of gravitation and electromagnetism which has field equations which are (i) derivable from a variational principle, (ii) consistent with the notion of conservation of charge, and (iii) compatible with Maxwell's equations in a flat space. This energy-momentum tensor turns out to be quadratic in the first partial derivatives of the electromagnetic field tensor and depends upon the curvature tensor. The asymptotic behavior of this energy-momentum tensor is examined for solutions to Maxwell's equations in Minkowski space, and it is demonstrated that this energy-momentum tensor predicts regions of negative energy density in the vicinity of point sources

  5. Constrained gauge fields from spontaneous Lorentz violation

    DEFF Research Database (Denmark)

    Chkareuli, J. L.; Froggatt, C. D.; Jejelava, J. G.

    2008-01-01

    Spontaneous Lorentz violation realized through a nonlinear vector field constraint of the type AµAµ=M2 (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...... couplings when expressed in terms of the pure Goldstone vector modes. However, they do not lead to physical Lorentz violation due to the simultaneously generated gauge invariance. Udgivelsesdato: June 11...

  6. Finite N=1 SUSY gauge field theories

    International Nuclear Information System (INIS)

    Kazakov, D.I.

    1986-01-01

    The authors give a detailed description of the method to construct finite N=1 SUSY gauge field theories in the framework of N=1 superfields within dimensional regularization. The finiteness of all Green functions is based on supersymmetry and gauge invariance and is achieved by a proper choice of matter content of the theory and Yukawa couplings in the form Y i =f i (ε)g, where g is the gauge coupling, and the function f i (ε) is regular at ε=0 and is calculated in perturbation theory. Necessary and sufficient conditions for finiteness are determined already in the one-loop approximation. The correspondence with an earlier proposed approach to construct finite theories based on aigenvalue solutions of renormalization-group equations is established

  7. Gauge field theories. Part three. Renormalization

    International Nuclear Information System (INIS)

    Frampon, P.H.

    1978-01-01

    The renormalization of nonabelian gauge theories both with exact symmetry and with spontaneous symmetry breaking is discussed. The method of dimensional regularization is described and used in the ensuing discussion. Triangle anomalies and their implications and the method for cancellation of anomalies in an SU(2) x U(1) theory, introduction of the BRS form of local gauge transformation and its use for the iterative proof of renormalizability to all orders for pure Yang--Mills and with fermion and scalar matter fields are considered. Lastly for massive vectors arising from spontaneous breaking, the demonstration of renormalizability is given, using the 't Hooft gauges introduced first in 1971. While the treatment is not totally rigorous, all the principle steps are given. 108 references

  8. Field-theoretical investigations in nonlinear realizations of gauge symmetry

    International Nuclear Information System (INIS)

    Lee, Chenhan.

    1989-01-01

    A review of both linear realization and non-linear realization of gauge symmetries is given and the connection between the two recipes is carefully examined. The author then constructs both linear and non-linear realizations for of supersymmetric theories. The supermultiplets of the Goldstone modes contain Goldstone bosons, quasi-Goldstone bosons and quasi-Goldstone fermions. He makes an attempt to construct a specific model of a supersymmetric non-linear realization for the Nambu-Goldstone superfields and the quasi-Goldstone fermions are identified with the quarks and leptons. Further, he discusses a mechanism by which the components of the Nambu-Goldstone supermultiplets are given non-zero mass splittings by the coupling to a hidden sector. Next, he turns to anti-symmetric tensor gauge theories, which are shown to be classically equivalent to the non-linear models describing the complete symmetry breakdown. To study the quantum mechanical equivalence of these two models, he carries out the tensor gauge fixing and the quantization procedures for the anti-symmetric tensor theories and establish the global symmetry currents which connect the two models. He then builds the supersymmetric extensions of the anti-symmetric tensor gauge theories in both abelian and non-abelian versions. Such super-tensor gauge theories are shown, by using the superfield equations of motion, to be equivalent to the fully doubled supersymmetric non-linear models of complete symmetry breakdown

  9. Gauge field copies and Higgs mechanism

    International Nuclear Information System (INIS)

    Gleiser, M.

    1982-07-01

    From the algebric classification of the possible solutions of the necessary and sufficient condition for the existence of gauge field copies in two possible classes the Higgs mechanism for the potential obtained from the difference between two copied potentials is applied. It is shown that for class I 'electric type' it is possible to construct a vector field that satisfies an electromagnetic wave equation. For class I 'magnetic type', a vector field that satisfies a non-linear equation as a consequence of the non-abelianity of the theory, is obtained. It is shown that for class II it's not possible to apply the Higgs mechanism. A possible physical interpretation for the 'gauge field copies' phenomenon, is obtained. (author) [pt

  10. Shadow fields and local supersymmetric gauges

    International Nuclear Information System (INIS)

    Baulieu, L.; Bossard, G.; Sorella, S.P.

    2006-01-01

    To control supersymmetry and gauge invariance in super-Yang-Mills theories we introduce new fields, called shadow fields, which enable us to enlarge the conventional Faddeev-Popov framework and write down a set of useful Slavnov-Taylor identities. These identities allow us to address and answer the issue of the supersymmetric Yang-Mills anomalies, and to perform the conventional renormalization programme in a fully regularization-independent way

  11. 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

  12. Gauge field configurations in curved spacetimes (II)

    International Nuclear Information System (INIS)

    Boutaleb-Joutei, H.; Chakrabarti, A.; Comtet, A.

    1979-05-01

    One continues the study of gauge field configurations in curved spaces, using the formalism and results of a previous paper. A class of static, finite action, selfdual solutions of SU(2) gauge fields on a Euclidean section of de Sitter space is presented. The action depends on a continuous parameter. The spin connection solution is obtained as a particular case and a certain passage to the limiting case of a flat space is shown to reproduce the Euclidean Prasad-Sommerfield solution. The significance and possible interest of such solutions are discussed. The results are then generalized to a non-Einstein but conformally flat space, including de Sitter space as an Einstein limit. Next Baecklund type transformations are constructed starting from selfduality constraints for such curved spaces. These transformations are applied to the above mentioned solutions. The last two sections contain remarks on solutions with a background Robinson-Bertotti metric and on static, axially symmetric solutions respectively

  13. Zero energy gauge fields and the phases of a gauge theory

    International Nuclear Information System (INIS)

    Guendelman, E.I.

    1990-01-01

    A new approach to the definition of the phases of a Poincare invariant gauge theory is developed. It is based on the role of gauge transformations that change the asymptotic value of the gauge fields from zero to a constant. In the context of theories without Higgs fields, this symmetry can be spontaneously broken when the gauge fields are massless particles, explicitly broken when the gauge fields develop a mass. Finally, the vacuum can be invariant under this transformation, this last case can be achieved when the theory has a violent infrared behavior, which in some theories can be connected to a confinement mechanism

  14. Expansion Formulation of General Relativity: the Gauge Functions for Energy-Momentum Tensor

    Science.gov (United States)

    Beloushko, Konstantin; Karbanovski, Valeri

    , that the problem consist not in a existence of the GF energy, and in it localization which is forbidden by an equivalence principle. We shall consider the possibility for generalization of transformation (ref{GrindEQ__1_3_}) on the Riemann space-time for EMT satisfying a condition (ref{GrindEQ__1_1_}). This problem reduce to construction of tensor h(ikl) which will be consistent with a constraint (ref{GrindEQ__1_4_}) and with requirement begin{equation} ⪉bel{GrindEQ__2_1_} h^{ikl} _{;l;k} =0. For such EMT a following transformation is permissible begin{equation} ⪉bel{GrindEQ__2_2_} T^{ik} to tilde{T}^{ik} =T^{ik} +h^{ikl} _{;l} , which not violate the property (ref{GrindEQ__1_1_}). As begin{equation} ⪉bel{GrindEQ__2_3_} h^{ikl} _{;l;k} =frac{1}{2} left(h^{ikl} -h^{ilk} right)_{;l;k} =frac{1}{2} R^{i} _{mlk} h^{mlk} , then from (ref{GrindEQ__2_1_}) it is follows begin{equation} ⪉bel{GrindEQ__2_4_} R^{i} _{mlk} h^{mlk} =0. For a flat space-time the last condition is reduced to identity (i.e. R(i) _{klm} =0). Therefore the requirement (ref{GrindEQ__2_4_}) can be interpreted as a ``Riemann's constraint'' for h(ikl) . References begin{enumerate} A. Einstein and M. Grossman - Z. Math. und Phys., 1913, B62, s.225. L.D. Landau and E.M. Lifshitz. The Classical Theory of Fields - New York, Pergamon, 1994. W. Pauli, A. Sommerfeld. Theory of Relativity - New York, Pergamon, 1985. D. Gilbert - Göttingen Nachrichten, 4 (1917) 4. A.A. Logunov “Lectures on the relativity and gravity theory”, N.P. Konopleva, V.N. Popov. The gauge field - Moscow, Atomizdat, 1988. (in Russian) V.A. Fock. The Theory of Space, Time and Gravitation - London, Pergamon, 1959. Ch. Misner, Kip S. Thorne, Jh. A. Wheeler. Gravitation. - San Francisco, W.H. Freeman and Company, 1973.

  15. Fundamental problems of gauge field theory

    International Nuclear Information System (INIS)

    Velo, G.; Wightman, A.S.

    1986-01-01

    As a result of the experimental and theoretical developments of the last two decades, gauge field theory, in one form or another, now provides the standard language for the description of Nature; QCD and the standard model of the electroweak interactions illustrate this point. It is a basic task of mathematical physics to provide a solid foundation for these developments by putting the theory in a physically transparent and mathematically rigorous form. The lecture notes collected in this volume concentrate on the many unsolved problems which arise here, and on the general ideas and methods which have been proposed for their solution. In particular, the use of rigorous renormalization group methods to obtain control over the continuum limit of lattice gauge field theories, the exploration of the extraordinary enigmatic connections between Kac-Moody-Virasoro algebras and string theory, and the systematic use of the theory of local algebras and indefinite metric spaces to classify the charged C* states in gauge field theories are mentioned

  16. Energy-momentum tensor in the quantum field theory

    International Nuclear Information System (INIS)

    Azakov, S.I.

    1977-01-01

    An energy-momentum tensor in the scalar field theory is built. The tensor must satisfy the finiteness requirement of the Green function. The Green functions can always be made finite by renormalizations in the S-matrix by introducing counter terms into the Hamiltonian (or Lagrangian) of the interaction. Such a renormalization leads to divergencies in the Green functions. Elimination of these divergencies requires the introduction of new counter terms, which must be taken into account in the energy-momentum tensor

  17. Flavour fields in steady state: stress tensor and free energy

    International Nuclear Information System (INIS)

    Banerjee, Avik; Kundu, Arnab; Kundu, Sandipan

    2016-01-01

    The dynamics of a probe brane in a given gravitational background is governed by the Dirac-Born-Infeld action. The corresponding open string metric arises naturally in studying the fluctuations on the probe. In Gauge-String duality, it is known that in the presence of a constant electric field on the worldvolume of the probe, the open string metric acquires an event horizon and therefore the fluctuation modes on the probe experience an effective temperature. In this article, we bring together various properties of such a system to a formal definition and a subsequent narration of the effective thermodynamics and the stress tensor of the corresponding flavour fields, also including a non-vanishing chemical potential. In doing so, we point out a potentially infinitely-degenerate scheme-dependence of regularizing the free energy, which nevertheless yields a universal contribution in certain cases. This universal piece appears as the coefficient of a log-divergence in free energy when a space-filling probe brane is embedded in AdS d+1 -background, for d=2,4, and is related to conformal anomaly. For the special case of d=2, the universal factor has a striking resemblance to the well-known heat current formula in (1+1)-dimensional conformal field theory in steady-state, which endows a plausible physical interpretation to it. Interestingly, we observe a vanishing conformal anomaly in d=6.

  18. Linear b-gauges for open string fields

    International Nuclear Information System (INIS)

    Kiermaier, Michael; Zwiebach, Barton; Sen, Ashoke

    2008-01-01

    Motivated by Schnabl's gauge choice, we explore open string perturbation theory in gauges where a linear combination of antighost oscillators annihilates the string field. We find that in these linear b-gauges different gauge conditions are needed at different ghost numbers. We derive the full propagator and prove the formal properties which guarantee that the Feynman diagrams reproduce the correct on-shell amplitudes. We find that these properties can fail due to the need to regularize the propagator, and identify a large class of linear b-gauges for which they hold rigorously. In these gauges the propagator has a non-anomalous Schwinger representation and builds Riemann surfaces by adding strip-like domains. Projector-based gauges, like Schnabl's, are not in this class of gauges but we construct a family of regular linear b-gauges which interpolate between Siegel gauge and Schnabl gauge

  19. Noether symmetries, energy-momentum tensors, and conformal invariance in classical field theory

    International Nuclear Information System (INIS)

    Pons, Josep M.

    2011-01-01

    In the framework of classical field theory, we first review the Noether theory of symmetries, with simple rederivations of its essential results, with special emphasis given to the Noether identities for gauge theories. With this baggage on board, we next discuss in detail, for Poincare invariant theories in flat spacetime, the differences between the Belinfante energy-momentum tensor and a family of Hilbert energy-momentum tensors. All these tensors coincide on shell but they split their duties in the following sense: Belinfante's tensor is the one to use in order to obtain the generators of Poincare symmetries and it is a basic ingredient of the generators of other eventual spacetime symmetries which may happen to exist. Instead, Hilbert tensors are the means to test whether a theory contains other spacetime symmetries beyond Poincare. We discuss at length the case of scale and conformal symmetry, of which we give some examples. We show, for Poincare invariant Lagrangians, that the realization of scale invariance selects a unique Hilbert tensor which allows for an easy test as to whether conformal invariance is also realized. Finally we make some basic remarks on metric generally covariant theories and classical field theory in a fixed curved background.

  20. Gauge-invariant intense-field approximations to all orders

    International Nuclear Information System (INIS)

    Faisal, F H M

    2007-01-01

    We present a gauge-invariant formulation of the so-called strong-field KFR approximations in the 'velocity' and 'length' gauges and demonstrate their equivalence in all orders. The theory thus overcomes a longstanding discrepancy between the strong-field velocity and the length-gauge approximations for non-perturbative processes in intense laser fields. (fast track communication)

  1. 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 ...

  2. On energy-momentum tensors of gravitational field

    International Nuclear Information System (INIS)

    Nikishov, A.I.

    2001-01-01

    The phenomenological approach to gravitation is discussed in which the 3-graviton interaction is reduced to the interaction of each graviton with the energy-momentum tensor of two others. If this is so, (and in general relativity this is not so), then the problem of choosing the correct energy-momentum tensor comes to finding the right 3-graviton vertex. Several energy-momentum tensors od gravitational field are considered and compared in the lowest approximation. Each of them together with the energy-momentum tensor of point-like particles satisfies the conservation laws when equations of motion of particles are the same as in general relativity. It is shown that in Newtonian approximation the considered tensors differ one from other in the way their energy density is distributed between energy density of interaction (nonzero only at locations of particles) and energy density of gravitational field. Stating from Lorentz invariance, the Lagrangians for spin-2, mass-0 field are considered [ru

  3. A gauge field theory of fermionic continuous-spin particles

    Energy Technology Data Exchange (ETDEWEB)

    Bekaert, X., E-mail: xavier.bekaert@lmpt.univ-tours.fr [Laboratoire de Mathématiques et Physique Théorique, Unité Mixte de Recherche 7350 du CNRS, Fédération de Recherche 2964 Denis Poisson, Université François Rabelais, Parc de Grandmont, 37200 Tours (France); B.W. Lee Center for Fields, Gravity and Strings, Institute for Basic Science, Daejeon (Korea, Republic of); Najafizadeh, M., E-mail: mnajafizadeh@gmail.com [Laboratoire de Mathématiques et Physique Théorique, Unité Mixte de Recherche 7350 du CNRS, Fédération de Recherche 2964 Denis Poisson, Université François Rabelais, Parc de Grandmont, 37200 Tours (France); Department of Physics, Faculty of Sciences, University of Kurdistan, 66177-15177 Sanandaj (Iran, Islamic Republic of); Setare, M.R., E-mail: rezakord@ipm.ir [Department of Physics, Faculty of Sciences, University of Kurdistan, 66177-15177 Sanandaj (Iran, Islamic Republic of)

    2016-09-10

    In this letter, we suggest a local covariant action for a gauge field theory of fermionic Continuous-Spin Particles (CSPs). The action is invariant under gauge transformations without any constraint on both the gauge field and the gauge transformation parameter. The Fang–Fronsdal equations for a tower of massless fields with all half-integer spins arise as a particular limit of the equation of motion of fermionic CSPs.

  4. A gauge field theory of fermionic continuous-spin particles

    International Nuclear Information System (INIS)

    Bekaert, X.; Najafizadeh, M.; Setare, M.R.

    2016-01-01

    In this letter, we suggest a local covariant action for a gauge field theory of fermionic Continuous-Spin Particles (CSPs). The action is invariant under gauge transformations without any constraint on both the gauge field and the gauge transformation parameter. The Fang–Fronsdal equations for a tower of massless fields with all half-integer spins arise as a particular limit of the equation of motion of fermionic CSPs.

  5. Gauge field theories. 3. enl. ed.

    International Nuclear Information System (INIS)

    Frampton, Paul H.

    2008-01-01

    Gauge theories provide a unified framework to describe three of the four universal forces known so far: the quantum field theories of electromagnetism, the weak force and the strong force. They are an essential part of the so-called standard model of particles and matter. The first edition of this work was quickly adopted by universities and other institutions of higher learning around the world. Completely updated, this third edition continues to be an ideal reference on the subject. In total, more than a quarter of the content has been changed or added. The tried-and-tested logical structuring of the material on gauge invariance, quantization, and renormalization has been retained, while the chapters on electroweak interactions and model building have been revised. Completely new is the chapter on conformality. As in the past, Frampton emphasizes formalism rather than experiments and provides sufficient detail for readers wishing to do their own calculations or pursue theoretical physics research: - gauge invariance, - quantization, - renormalization, - electroweak forces, - renormalization group, - quantum chromodynamics, - model building, - conformality. (orig.)

  6. Gravitational Goldstone fields from affine gauge theory

    Science.gov (United States)

    Tresguerres, Romualdo; Mielke, Eckehard W.

    2000-08-01

    In order to facilitate the application of standard renormalization techniques, gravitation should be described, in the pure connection formalism, as a Yang-Mills theory of a certain spacetime group, say the Poincaré or the affine group. This embodies the translational as well as the linear connection. However, the coframe is not the standard Yang-Mills-type gauge field of the translations, since it lacks the inhomogeneous gradient term in the gauge transformations. By explicitly restoring this ``hidden'' piece within the framework of nonlinear realizations, the usual geometrical interpretation of the dynamical theory becomes possible, and in addition one can avoid the metric or coframe degeneracy which would otherwise interfere with the integrations within the path integral. We claim that nonlinear realizations provide the general mathematical scheme for the foundation of gauge theories of spacetime symmetries. When applied to construct the Yang-Mills theory of the affine group, tetrads become identified with nonlinear translational connections; the anholonomic metric no longer constitutes an independent gravitational potential, since its degrees of freedom reveal a correspondence to eliminateable Goldstone bosons. This may be an important advantage for quantization.

  7. 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.

  8. Light-induced gauge fields for ultracold atoms

    International Nuclear Information System (INIS)

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

    2014-01-01

    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. (review article)

  9. String field theory-inspired algebraic structures in gauge theories

    International Nuclear Information System (INIS)

    Zeitlin, Anton M.

    2009-01-01

    We consider gauge theories in a string field theory-inspired formalism. The constructed algebraic operations lead, in particular, to homotopy algebras of the related Batalin-Vilkovisky theories. We discuss an invariant description of the gauge fixing procedure and special algebraic features of gauge theories coupled to matter fields.

  10. Effective field theory approaches for tensor potentials

    Energy Technology Data Exchange (ETDEWEB)

    Jansen, Maximilian

    2016-11-14

    Effective field theories are a widely used tool to study physical systems at low energies. We apply them to systematically analyze two and three particles interacting via tensor potentials. Two examples are addressed: pion interactions for anti D{sup 0}D{sup *0} scattering to dynamically generate the X(3872) and dipole interactions for two and three bosons at low energies. For the former, the one-pion exchange and for the latter, the long-range dipole force induce a tensor-like structure of the potential. We apply perturbative as well as non-perturbative methods to determine low-energy observables. The X(3872) is of major interest in modern high-energy physics. Its exotic characteristics require approaches outside the range of the quark model for baryons and mesons. Effective field theories represent such methods and provide access to its peculiar nature. We interpret the X(3872) as a hadronic molecule consisting of neutral D and D{sup *} mesons. It is possible to apply an effective field theory with perturbative pions. Within this framework, we address chiral as well as finite volume extrapolations for low-energy observables, such as the binding energy and the scattering length. We show that the two-point correlation function for the D{sup *0} meson has to be resummed to cure infrared divergences. Moreover, next-to-leading order coupling constants, which were introduced by power counting arguments, appear to be essential to renormalize the scattering amplitude. The binding energy as well as the scattering length display a moderate dependence on the light quark masses. The X(3872) is most likely deeper bound for large light quark masses. In a finite volume on the other hand, the binding energy significantly increases. The dependence on the light quark masses and the volume size can be simultaneously obtained. For bosonic dipoles we apply a non-perturbative, numerical approach. We solve the Lippmann-Schwinger equation for the two-dipole system and the Faddeev

  11. On scalar and vector fields coupled to the energy-momentum tensor

    Science.gov (United States)

    Jiménez, Jose Beltrán; Cembranos, Jose A. R.; Sánchez Velázquez, Jose M.

    2018-05-01

    We consider theories for scalar and vector fields coupled to the energy-momentum tensor. Since these fields also carry a non-trivial energy-momentum tensor, the coupling prescription generates self-interactions. In analogy with gravity theories, we build the action by means of an iterative process that leads to an infinite series, which can be resumed as the solution of a set of differential equations. We show that, in some particular cases, the equations become algebraic and that is also possible to find solutions in the form of polynomials. We briefly review the case of the scalar field that has already been studied in the literature and extend the analysis to the case of derivative (disformal) couplings. We then explore theories with vector fields, distinguishing between gauge-and non-gauge-invariant couplings. Interactions with matter are also considered, taking a scalar field as a proxy for the matter sector. We also discuss the ambiguity introduced by superpotential (boundary) terms in the definition of the energy-momentum tensor and use them to show that it is also possible to generate Galileon-like interactions with this procedure. We finally use collider and astrophysical observations to set constraints on the dimensionful coupling which characterises the phenomenology of these models.

  12. Relaxation methods for gauge field equilibrium equations

    International Nuclear Information System (INIS)

    Adler, S.L.; Piran, T.

    1984-01-01

    This article gives a pedagogical introduction to relaxation methods for the numerical solution of elliptic partial differential equations, with particular emphasis on treating nonlinear problems with delta-function source terms and axial symmetry, which arise in the context of effective Lagrangian approximations to the dynamics of quantized gauge fields. The authors present a detailed theoretical analysis of three models which are used as numerical examples: the classical Abelian Higgs model (illustrating charge screening), the semiclassical leading logarithm model (illustrating flux confinement within a free boundary or ''bag''), and the axially symmetric Bogomol'nyi-Prasad-Sommerfield monopoles (illustrating the occurrence of p topological quantum numbers in non-Abelian gauge fields). They then proceed to a self-contained introduction to the theory of relaxation methods and allied iterative numerical methods and to the practical aspects of their implementation, with attention to general issues which arise in the three examples. The authors conclude with a brief discussion of details of the numerical solution of the models, presenting sample numerical results

  13. Invariant gauge families inherent in Abelian-gauge field theory. [Scalar dipole ghost field, free-field equations

    Energy Technology Data Exchange (ETDEWEB)

    Yokoyama, Kan-ichi; Kubo, Reijiro

    1974-12-01

    The framework of the Nakanishi-Lautrup formalism should be enlarged by introducing a scalar dipole ghost field B(x), which is called gauge on field, together with its pair field. By taking free Lagrangian density, Free-field equations can be described. The vacuum is defined by using a neutral vector field U..mu..(x). The state-vector space is generated by the adjoining conjugates of U..mu..sup((+))(x), and auxiliary fields B(x), B/sub 1/(x) and B/sub 2/(x), which were introduced in the form of the Lagrangian density. The physical states can be defined by the supplementary conditions of the form B/sub 1/sup((+))(x) 1 phys>=B/sub 2/sup((+))(x) 1 phys>=0. It is seen that all the field equations and all the commutators are kept form-invariant, and that the gauge parameter ..cap alpha.. is transformed into ..cap alpha..' given by ..cap alpha..'=..cap alpha..+lambda, with epsilon unchanged. The Lagrangian density is specified only by the gauge invariant parameter epsilon. The gauge structure of theory has universal meaning over whole Abelian-gauge field. C-number gauge transformation and the gauge structure in the presence of interaction are also discussed.

  14. Invariant structures in gauge theories and confinement

    International Nuclear Information System (INIS)

    Prokhorov, L.V.; Shabanov, S.V.

    1991-01-01

    The problem of finding all gauge invariants is considered in connection with the problem of confinement. Polylocal gauge tensors are introduced and studied. It is shown (both in physical and pure geometrical approaches) that the path-ordered exponent is the only fundamental bilocal gauge tensor, which means that any irreducible polylocal gauge tensor is built of P-exponents and local tensors (matter fields). The simplest invariant structures in electrodynamics, chromodynamics and a theory with the gauge group SU(2) are considered separately. 23 refs.; 2 figs

  15. Four dimensional sigma model coupled to the metric tensor field

    International Nuclear Information System (INIS)

    Ghika, G.; Visinescu, M.

    1980-02-01

    We discuss the four dimensional nonlinear sigma model with an internal O(n) invariance coupled to the metric tensor field satisfying Einstein equations. We derive a bound on the coupling constant between the sigma field and the metric tensor using the theory of harmonic maps. A special attention is paid to Einstein spaces and some new explicit solutions of the model are constructed. (author)

  16. Reduction of the Poincare gauge field equations by means of a duality rotation

    International Nuclear Information System (INIS)

    Mielke, E.W.

    1981-10-01

    A rather general procedure is developed in order to reduce the two field equations of the Poincare gauge theory of gravity by a modified ansatz for the curvature tensor involving double duality. In the case of quasi-linear Lagrangians of the Yang-Mills type it is shown that non-trivial torsion solutions with duality properties necessarily ''live'' on an Einstein space as metrical background. (author)

  17. Dynamical chaos of nonabelian gauge fields

    International Nuclear Information System (INIS)

    Matinyan, S.G.

    1985-01-01

    A special class of the Yang - Mills field-the spatially homogeneous fields (Yan - Mills classical mechanics)-having no analog in the linear abelian electrodynamics is studied. Both the computer and analytical approaches show that such fields possess dynamical stochasticity, this allowing one to claim that the Yang - Mills classical equations without external sources represent a non-integrable system. The Higgs mechanism eliminates this stochasticity: at some expectation value of scalar field, a phase transition of disorder-order (confinement-deconfinement) type takes plce. The system with external sources behaves apparently analogously. A relation of the discovered stochasticity with the dimensional reduction mechanism in the macroscopic systems as well as with colour confinement is considered. It is shown that the presence of the random (Gaussian) currents in vacuum leads to confinement of fields generated by those currents. Attention is paid to the possible manifestation of the revealed stochasticity of the classical non-abelian gauge fields in the multiple hadrnoproduction processes which apparently reflect the universal stochastic regularities typical of the systems of quite different nature

  18. Dynamical chaos of nonabelian gauge fields

    Energy Technology Data Exchange (ETDEWEB)

    Matinyan, S G

    1985-01-01

    A special class of the Yang - Mills field-the spatially homogeneous fields (Yan - Mills classical mechanics)-having no analog in the linear abelian electrodynamics is studied. Both the computer and analytical approaches show that such fields possess dynamical stochasticity, this allowing one to claim that the Yang - Mills classical equations without external sources represent a non-integrable system. The Higgs mechanism eliminates this stochasticity: at some expectation value of scalar field, a phase transition of disorder-order (confinement-deconfinement) type takes plce. The system with external sources behaves apparently analogously. A relation of the discovered stochasticity with the dimensional reduction mechanism in the macroscopic systems as well as with colour confinement is considered. It is shown that the presence of the random (Gaussian) currents in vacuum leads to confinement of fields generated by those currents. Attention is paid to the possible manifestation of the revealed stochasticity of the classical non-abelian gauge fields in the multiple hadrnoproduction processes which apparently reflect the universal stochastic regularities typical of the systems of quite different nature.

  19. Some physico-geometrical remarks on gauge fields

    International Nuclear Information System (INIS)

    Ikeda, S.

    1976-01-01

    The gauge fields introduced to accomplish gauge invariance under Poincare and Weyl gauge transformations in general relativity are found a new to be absorbed into the covariant derivative operators. Some torsional properties associated with them are also discussed in connection with the principle of minimally coupling and the equivalence principle

  20. Topics in gravitation and gauge fields

    International Nuclear Information System (INIS)

    Leen, T.K.

    1982-01-01

    The theoretical studies presented here address three distinct topics. The first deals with quantum-mechanical effects of classical gravitational radiation. Specifically, the use of the interstellar medium itself as a remote quantum-mechanical detector of gravitational waves is investigated. This study is motivated by the presumed existence of atomic hydrogen in the vicinity of astrophysical sources of gravitational radiation. Space-time curvature produces uniquely identifiable shifts in atomic hydrogen energy levels. The oscillating level shifts induced by a passing gravitational wave could conceivably be detected spectroscopically. Accordingly the level shifts for both low-lying and highly excited states of single electron atoms immersed in gravitational radiation have been studied. The second two topics deal with the theory of quantized fields on curved space-times. In the first of these studies, a naive model of cosmological baryon synthesis is examined. The model incorporates a hard CP violation as well as a baryon (and lepton) non-conserving interaction and is thus capable of generating an excess of matter over antimatter. The time dependent background geometry of the early universe drives the interaction producing net excess of baryon/lepton pairs. In the final topic, the question of renormalizability of non-Abelian gauge fields theories in a general curved space-time is addressed. All modern theories of elementary particle physics are gauge theories and one would like to know if their perturbative expansions continue to be well defined (i.e. renormalizable) on curved backgrounds. In general, one is interested in knowing if field theories renormalizable in Minkowski space remain so in a general curved space-time

  1. Vacuum structure of the SU(3) gauge field theory in the Coulomb gauge

    International Nuclear Information System (INIS)

    Yee, J.H.; Viswanathan, K.S.

    1978-01-01

    The SU(3) gauge field is studied in the Coulomb gauge. The Gribov ambiguities arising in the Coulomb gauge are analysed. Restricting to a class of spherically symmetric vacua it is shown that there exist non-trivial vacua characterized by a topological number eta=0, +-1/2, and +-2. This must be contrasted with the spherically symmetric SU(2) vacua which are characterized by eta=0, +-1/2. (Auth.)

  2. Cutoff effects on energy-momentum tensor correlators in lattice gauge theory

    International Nuclear Information System (INIS)

    Meyer, Harvey B.

    2009-01-01

    We investigate the discretization errors affecting correlators of the energy-momentum tensor T μν at finite temperature in SU(N c ) gauge theory with the Wilson action and two different discretizations of T μν . We do so by using lattice perturbation theory and non-perturbative Monte-Carlo simulations. These correlators, which are functions of Euclidean time x 0 and spatial momentum p, are the starting point for a lattice study of the transport properties of the gluon plasma. We find that the correlator of the energy ∫d 3 x T 00 has much larger discretization errors than the correlator of momentum ∫d 3 x T 0k . Secondly, the shear and diagonal stress correlators (T 12 and T kk ) require N τ ≥ 8 for the Tx 0 = 1/2 point to be in the scaling region and the cutoff effect to be less than 10%. We then show that their discretization errors on an anisotropic lattice with a σ /a τ = 2 are comparable to those on the isotropic lattice with the same temporal lattice spacing. Finally, we also study finite p correlators.

  3. Correspondence between quantum gauge theories without ghost fields and their covariantly quantized theories with ghost fields

    International Nuclear Information System (INIS)

    Cheng Hung; Tsai Ercheng

    1986-01-01

    We give a correspondence formula which equates transition amplitudes in a quantum gauge field theory without ghost fields to those in a quantum theory with the gauge fields covariantly quantized and coupled to ghost fields. (orig.)

  4. Metric interpretation of gauge fields in noncommutative geometry

    International Nuclear Information System (INIS)

    Martinetti, P.

    2007-01-01

    We shall give an overview of the metric interpretation of gauge fields in noncommutative geometry, via Connes distance formula. Especially we shall focus on the Higgs fields in the standard model, and gauge fields in various models of fiber bundle. (author)

  5. Localization of abelian gauge fields on thick branes

    Energy Technology Data Exchange (ETDEWEB)

    Vaquera-Araujo, Carlos A. [Universidad de Colima, Facultad de Ciencias, CUICBAS, Colima (Mexico); Corradini, Olindo [Universidad Autonoma de Chiapas, Ciudad Universitaria, Facultad de Ciencias en Fisica y Matematicas, Tuxtla Gutierrez (Mexico); Universita di Modena e Reggio Emilia, Dipartimento di Scienze Fisiche, Informatiche e Matematiche, Modena (Italy)

    2015-02-01

    In this work, we explore a mechanism for abelian gauge field localization on thick branes based on a five-dimensional Stueckelberg-like action. A normalizable zero mode is found through the identification of a suitable coupling function between the brane and the gauge field. The same mechanism is studied for the localization of the abelian Kalb-Ramond field. (orig.)

  6. Vortex operators in gauge field theories

    International Nuclear Information System (INIS)

    Polchinski, J.

    1980-07-01

    Several related aspects of the 't Hooft vortex operator are studied. The current picture of the vacuum of quantum chromodynamics, the idea of dual field theories, and the idea of the vortex operator are reviewed first. The Abelian vortex operator written in terms of elementary fields and the calculation of its Green's functions are considered. A two-dimensional solvable model of a Dirac string is presented. The expression of the Green's functions more neatly in terms of Wu and Yang's geometrical idea of sections is addressed. The renormalization of the Green's functions of two kinds of Abelian looplike operators, the Wilson loop and the vortex operator, is studied; for both operators only an overall multiplicative renormalization is needed. In the case of the vortex this involves a surprising cancellation. Next, the dependence of the Green's functions of the Wilson and 't Hooft operators on the nature of the vacuum is discussed. The cluster properties of the Green's functions are emphasized. It is seen that the vortex operator in a massive Abelian theory always has surface-like clustering. The form of Green's functions in terms of Feynman graphs is the same in Higgs and symmetric phases; the difference appears in the sum over all tadpole trees. Finally, systems having fields in the fundamental representation are considered. When these fields enter only weakly into the dynamics, a vortex-like operator is anticipated. Any such operator can no longer be local looplike, but must have commutators at long range. A U(1) lattice gauge theory with two matter fields, one singly charged (fundamental) and one doubly charged (adjoint), is examined. When the fundamental field is weakly coupled, the expected phase transitions are found. When it is strongly coupled, the operator still appears to be a good order parameter, a discontinuous change in its behavior leads to a new phase transition. 18 figures

  7. Higher groupoid bundles, higher spaces, and self-dual tensor field equations

    Energy Technology Data Exchange (ETDEWEB)

    Jurco, Branislav [Charles University in Prague, Faculty of Mathematics and Physics, Mathematical Institute, Prague (Czech Republic); Saemann, Christian [Maxwell Institute for Mathematical Sciences, Department of Mathematics, Heriot-Watt University, Edinburgh (United Kingdom); Wolf, Martin [Department of Mathematics, University of Surrey, Guildford (United Kingdom)

    2016-08-15

    We develop a description of higher gauge theory with higher groupoids as gauge structure from first principles. This approach captures ordinary gauge theories and gauged sigma models as well as their categorifications on a very general class of (higher) spaces comprising presentable differentiable stacks, as e.g. orbifolds. We start off with a self-contained review on simplicial sets as models of (∞, 1)-categories. We then discuss principal bundles in terms of simplicial maps and their homotopies. We explain in detail a differentiation procedure, suggested by Severa, that maps higher groupoids to L{sub ∞}-algebroids. Generalising this procedure, we define connections for higher groupoid bundles. As an application, we obtain six-dimensional superconformal field theories via a Penrose-Ward transform of higher groupoid bundles over a twistor space. This construction reduces the search for non-Abelian self-dual tensor field equations in six dimensions to a search for the appropriate (higher) gauge structure. The treatment aims to be accessible to theoretical physicists. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  8. Higher groupoid bundles, higher spaces, and self-dual tensor field equations

    International Nuclear Information System (INIS)

    Jurco, Branislav; Saemann, Christian; Wolf, Martin

    2016-01-01

    We develop a description of higher gauge theory with higher groupoids as gauge structure from first principles. This approach captures ordinary gauge theories and gauged sigma models as well as their categorifications on a very general class of (higher) spaces comprising presentable differentiable stacks, as e.g. orbifolds. We start off with a self-contained review on simplicial sets as models of (∞, 1)-categories. We then discuss principal bundles in terms of simplicial maps and their homotopies. We explain in detail a differentiation procedure, suggested by Severa, that maps higher groupoids to L ∞ -algebroids. Generalising this procedure, we define connections for higher groupoid bundles. As an application, we obtain six-dimensional superconformal field theories via a Penrose-Ward transform of higher groupoid bundles over a twistor space. This construction reduces the search for non-Abelian self-dual tensor field equations in six dimensions to a search for the appropriate (higher) gauge structure. The treatment aims to be accessible to theoretical physicists. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  9. On the energy-momentum tensor in Moyal space

    International Nuclear Information System (INIS)

    Balasin, Herbert; Schweda, Manfred; Blaschke, Daniel N.; Gieres, Francois

    2015-01-01

    We study the properties of the energy-momentum tensor of gauge fields coupled to matter in non-commutative (Moyal) space. In general, the non-commutativity affects the usual conservation law of the tensor as well as its transformation properties (gauge covariance instead of gauge invariance). It is well known that the conservation of the energy-momentum tensor can be achieved by a redefinition involving another star-product. Furthermore, for a pure gauge theory it is always possible to define a gauge invariant energy-momentum tensor by means of a Wilson line. We show that the last two procedures are incompatible with each other if couplings of gauge fields to matter fields (scalars or fermions) are considered: The gauge invariant tensor (constructed via Wilson line) does not allow for a redefinition assuring its conservation, and vice versa the introduction of another star-product does not allow for gauge invariance by means of a Wilson line. (orig.)

  10. Energy-momentum tensor in quantum field theory

    International Nuclear Information System (INIS)

    Fujikawa, K.

    1981-01-01

    The definition of the energy-momentum tensor as a source current coupled to the background gravitational field receives an important modification in quantum theory. In the path-integral approach, the manifest covariance of the integral measure under general coordinate transformations dictates that field variables with weight 1/2 should be used as independent integration variables. An improved energy-momentum tensor is then generated by the variational derivative, and it gives rise to well-defined gravitational conformal (Weyl) anomalies. In the flat--space-time limit, all the Ward-Takahashi identities associated with space-time transformations including the global dilatation become free from anomalies in terms of this energy-momentum tensor, reflecting the general covariance of the integral measure; the trace of this tensor is thus finite at zero momentum transfer for renormalizable theories. The Jacobian for the local conformal transformation, however, becomes nontrivial, and it gives rise to an anomaly for the conformal identity. All the familiar anomalies are thus reduced to either chiral or conformal anomalies. The consistency of the dilatation and conformal identities at vanishing momentum transfer determines the trace anomaly of this energy-momentum tensor in terms of the renormalization-group b function and other parameters. In contrast, the trace of the conventional energy-momentum tensor generally diverges even at vanishing momentum transfer depending on the regularization scheme, and it is subtractively renormalized. We also explain how the apparently different renormalization properties of the chiral and trace anomalies arise

  11. Vortex operators in gauge field theories

    International Nuclear Information System (INIS)

    Polchinski, J.G.

    1980-01-01

    We study several related aspects of the t Hooft vortex operator. The first chapter reviews the current picture of the vacuum of quantum chromodynamics, the idea of dual field theories, and the idea of the vortex operator. The second chapter deals with the Abelian vortex operator written in terms of elementary fields and with the calculation of its Green's functions. The Dirac veto problem appears in a new guise. We present a two dimensional solvable model of a Dirac string. This leads us to a new solution of the veto problem; we discuss its extension to four dimensions. We then show how the Green's functions can be expressed more neatly in terms of Wu and Yang's geometrical idea of sections. In the third chapter we discuss the dependence of the Green's functions of the Wilson and t Hooft operators on the nature of the vacuum. In the fourth chapter we consider systems which have fields in the fundamental representation, so that there are no vortex operators. When these fields enter only weakly into the dynamics, as is the case in QCD and in real superconductors, we would expect to be able to define a vortex-like operator. We show that any such operator can no longer be local looplike, but must have commutators at long range. We can still find an operator with useful properties, its cluster property, though more complicated than that of the usual vortex operator, still appears to distinguish Higgs, confining and perturbative phases. To test this, we consider a U(1) lattice gauge theory with two matter fields, one singly charged (fundamental) and one doubly charged (adjoint)

  12. On the axial anomalies in external tensor fields

    International Nuclear Information System (INIS)

    Khudaverdyan, O.M.; Mkrtchyan, R.L.; Zurabyan, L.A.

    1985-01-01

    Computation of the axial anomaly for Dirac fermions in external tensor fields is studied. The sequence of the supersymmetric one-dimensional models is presented. Their supercharges are equal, after quantization, to Dirac operators in external tensor fields, and the density of Witten's partition function gives the anomaly. It is shown that action in the corresponding path integral differs from the classical one. Gaussian approximation gives the anomaly only in the case of third-rank tensor with zero exterior derivative and in that case anomaly is calculated in all dimensions. The interpretation of that field as the torsion of gravitational field and also connection with the results of Witten and Alvarez-Gaume and Atiyah-Singer index theorem are discussed

  13. Gauge invariance and canonical quantization applied in the study of internal structure of gauge field systems

    International Nuclear Information System (INIS)

    Wang Fan; Chen Xiangsong; Lue Xiaofu; Sun Weiming; Goldman, T.

    2010-01-01

    It is unavoidable to deal with the quark and gluon momentum and angular momentum contributions to the nucleon momentum and spin in the study of nucleon internal structure. However, we never have the quark and gluon momentum, orbital angular momentum and gluon spin operators which satisfy both the gauge invariance and the canonical momentum and angular momentum commutation relations. The conflicts between the gauge invariance and canonical quantization requirement of these operators are discussed. A new set of quark and gluon momentum, orbital angular momentum and spin operators, which satisfy both the gauge invariance and canonical momentum and angular momentum commutation relations, are proposed. The key point to achieve such a proper decomposition is to separate the gauge field into the pure gauge and the gauge covariant parts. The same conflicts also exist in QED and quantum mechanics and have been solved in the same manner. The impacts of this new decomposition to the nucleon internal structure are discussed.

  14. Multigrid methods for the computation of propagators in gauge fields

    International Nuclear Information System (INIS)

    Kalkreuter, T.

    1992-11-01

    In the present work generalizations of multigrid methods for propagators in gauge fields are investigated. We discuss proper averaging operations for bosons and for staggered fermions. An efficient algorithm for computing C numerically is presented. The averaging kernels C can be used not only in deterministic multigrid computations, but also in multigrid Monte Carlo simulations, and for the definition of block spins and blocked gauge fields in Monte Carlo renormalization group studies of gauge theories. Actual numerical computations of kernels and propagators are performed in compact four-dimensional SU(2) gauge fields. (orig./HSI)

  15. Numerical evaluation of the tensor bispectrum in two field inflation

    Energy Technology Data Exchange (ETDEWEB)

    Raveendran, Rathul Nath [The Institute of Mathematical Sciences, HBNI, CIT Campus, Chennai, 600113 India (India); Sriramkumar, L., E-mail: rathulnr@imsc.res.in, E-mail: sriram@physics.iitm.ac.in [Department of Physics, Indian Institute of Technology Madras, Chennai, 600036 India (India)

    2017-07-01

    We evaluate the dimensionless non-Gaussianity parameter h {sub NL}, that characterizes the amplitude of the tensor bispectrum, numerically for a class of two field inflationary models such as double inflation, hybrid inflation and aligned natural inflation. We compare the numerical results with the slow roll results which can be obtained analytically. In the context of double inflation, we also investigate the effects on h {sub NL} due to curved trajectories in the field space. We explicitly examine the validity of the consistency relation governing the tensor bispectrum in the squeezed limit. Lastly, we discuss the contribution to h {sub NL} due to the epoch of preheating in two field models.

  16. Numerical evaluation of the tensor bispectrum in two field inflation

    International Nuclear Information System (INIS)

    Raveendran, Rathul Nath; Sriramkumar, L.

    2017-01-01

    We evaluate the dimensionless non-Gaussianity parameter h NL , that characterizes the amplitude of the tensor bispectrum, numerically for a class of two field inflationary models such as double inflation, hybrid inflation and aligned natural inflation. We compare the numerical results with the slow roll results which can be obtained analytically. In the context of double inflation, we also investigate the effects on h NL due to curved trajectories in the field space. We explicitly examine the validity of the consistency relation governing the tensor bispectrum in the squeezed limit. Lastly, we discuss the contribution to h NL due to the epoch of preheating in two field models.

  17. Gauge principle for hyper(para) fields

    Energy Technology Data Exchange (ETDEWEB)

    Govorkov, A.B. (Joint Inst. for Nuclear Research, Dubna (USSR))

    1983-04-01

    A special representation for parafields is considered which is based on the use of the Clifford hypernumbers. The principle of gauge invariance under hypercomplex phase transformations of parafields is formulated. A special role of quaternion hyperfields and corresponding Yang-Mills lagrangian with the gauge SO(3)-symmetry is pointed out.

  18. 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/)

  19. Nonabelian gauge fields in the background of magnetic strings

    International Nuclear Information System (INIS)

    Wieczorek, E.

    1993-01-01

    Quantized nonabelian gauge fields are studied in the external classical background of a linear magnetic string. The determination of the gauge field propagator demands a specification of the string by suitable physical limiting procedures. The vacuum energy density is obtained after transforming the background problem into a Casimir problem. (orig.)

  20. New gauge symmetries in Witten's Ramond string field theory

    International Nuclear Information System (INIS)

    Kugo, Taichiro; Terao, Haruhiko

    1988-01-01

    Witten's Raymond string field theory is observed to possess new gauge symmetries, which guarantee the consistency and the equivalence of Witten's theory to the other formulation based on the constrained string field. The projection operator into the gauge-invariant sector is explicitly constructed using an operator similar to the picture changing operator. (orig.)

  1. Tensor fields on orbits of quantum states and applications

    Energy Technology Data Exchange (ETDEWEB)

    Volkert, Georg Friedrich

    2010-07-19

    On classical Lie groups, which act by means of a unitary representation on finite dimensional Hilbert spaces H, we identify two classes of tensor field constructions. First, as pull-back tensor fields of order two from modified Hermitian tensor fields, constructed on Hilbert spaces by means of the property of having the vertical distributions of the C{sub 0}-principal bundle H{sub 0} {yields} P(H) over the projective Hilbert space P(H) in the kernel. And second, directly constructed on the Lie group, as left-invariant representation-dependent operator-valued tensor fields (LIROVTs) of arbitrary order being evaluated on a quantum state. Within the NP-hard problem of deciding whether a given state in a n-level bi-partite quantum system is entangled or separable (Gurvits, 2003), we show that both tensor field constructions admit a geometric approach to this problem, which evades the traditional ambiguity on defining metrical structures on the convex set of mixed states. In particular by considering manifolds associated to orbits passing through a selected state when acted upon by the local unitary group U(n) x U(n) of Schmidt coefficient decomposition inducing transformations, we find the following results: In the case of pure states we show that Schmidt-equivalence classes which are Lagrangian submanifolds define maximal entangled states. This implies a stronger statement as the one proposed by Bengtsson (2007). Moreover, Riemannian pull-back tensor fields split on orbits of separable states and provide a quantitative characterization of entanglement which recover the entanglement measure proposed by Schlienz and Mahler (1995). In the case of mixed states we highlight a relation between LIROVTs of order two and a class of computable separability criteria based on the Bloch-representation (de Vicente, 2007). (orig.)

  2. Tensor fields on orbits of quantum states and applications

    International Nuclear Information System (INIS)

    Volkert, Georg Friedrich

    2010-01-01

    On classical Lie groups, which act by means of a unitary representation on finite dimensional Hilbert spaces H, we identify two classes of tensor field constructions. First, as pull-back tensor fields of order two from modified Hermitian tensor fields, constructed on Hilbert spaces by means of the property of having the vertical distributions of the C 0 -principal bundle H 0 → P(H) over the projective Hilbert space P(H) in the kernel. And second, directly constructed on the Lie group, as left-invariant representation-dependent operator-valued tensor fields (LIROVTs) of arbitrary order being evaluated on a quantum state. Within the NP-hard problem of deciding whether a given state in a n-level bi-partite quantum system is entangled or separable (Gurvits, 2003), we show that both tensor field constructions admit a geometric approach to this problem, which evades the traditional ambiguity on defining metrical structures on the convex set of mixed states. In particular by considering manifolds associated to orbits passing through a selected state when acted upon by the local unitary group U(n) x U(n) of Schmidt coefficient decomposition inducing transformations, we find the following results: In the case of pure states we show that Schmidt-equivalence classes which are Lagrangian submanifolds define maximal entangled states. This implies a stronger statement as the one proposed by Bengtsson (2007). Moreover, Riemannian pull-back tensor fields split on orbits of separable states and provide a quantitative characterization of entanglement which recover the entanglement measure proposed by Schlienz and Mahler (1995). In the case of mixed states we highlight a relation between LIROVTs of order two and a class of computable separability criteria based on the Bloch-representation (de Vicente, 2007). (orig.)

  3. Gauge field entanglement in Kitaev's honeycomb model

    Science.gov (United States)

    Dóra, Balázs; Moessner, Roderich

    2018-01-01

    A spin fractionalizes into matter and gauge fermions in Kitaev's spin liquid on the honeycomb lattice. This follows from a Jordan-Wigner mapping to fermions, allowing for the construction of a minimal entropy ground-state wave function on the cylinder. We use this to calculate the entanglement entropy by choosing several distinct partitionings. First, by partitioning an infinite cylinder into two, the -ln2 topological entanglement entropy is reconfirmed. Second, the reduced density matrix of the gauge sector on the full cylinder is obtained after tracing out the matter degrees of freedom. This allows for evaluating the gauge entanglement Hamiltonian, which contains infinitely long-range correlations along the symmetry axis of the cylinder. The matter-gauge entanglement entropy is (Ny-1 )ln2 , with Ny the circumference of the cylinder. Third, the rules for calculating the gauge sector entanglement of any partition are determined. Rather small correctly chosen gauge partitions can still account for the topological entanglement entropy in spite of long-range correlations in the gauge entanglement Hamiltonian.

  4. Mean field with corrections in lattice gauge theory

    International Nuclear Information System (INIS)

    Flyvbjerg, H.; Zuber, J.B.; Lautrup, B.

    1981-12-01

    A systematic expansion of the path integral for lattice gauge theory is performed around the mean field solution. In this letter the authors present the results for the pure gauge groups Z(2), SU(2) and SO(3). The agreement with Monte Carlo calculations is excellent. For the discrete group the calculation is performed with and without gauge fixing, whereas for the continuous groups gauge fixing is mandatory. In the case of SU(2) the absence of a phase transition is correctly signalled by mean field theory. (Auth.)

  5. On the hyperbolicity of Einstein's and other gauge field equations

    International Nuclear Information System (INIS)

    Friedrich, H.

    1985-01-01

    It is shown that Einstein's vacuum field equations (respectively the conformal vacuum field equations) in a frame formalism imply a symmetric hyperbolic system of ''reduce'' propagation equations for any choice of coordinate system and frame field (and conformal factor). Certain freely specifiable ''gauge source'' functions occurring in the reduced equations reflect the choice of gauge. Together with the initial data they determine the gauge uniquely. Their choice does not affect the isometry class (conformal class) of a solution of an initial value problem. By the same method symmetric hyperbolic propagation equations are obtained from other gauge field equations, irrespective of the gauge. Using the concept of source functions one finds that Einstein's field equation, considered as second order equations for the metric coefficients, are of wave equation type in any coordinate system. (orig.)

  6. On the generally invariant Lagrangians for the metric field and other tensor fields

    International Nuclear Information System (INIS)

    Novotny, J.

    1978-01-01

    The Krupka and Trautman method for the description of all generally invariant functions of the components of geometrical object fields is applied to the invariants of second degree of the metrical field and other tensor fields. The complete system of differential identities fulfilled by the invariants mentioned is found and it is proved that these invariants depend on the tensor quantities only. (author)

  7. Energy-momentum tensor in quantum field theory

    International Nuclear Information System (INIS)

    Fujikawa, Kazuo.

    1980-12-01

    The definition of the energy-momentum tensor as a source current coupled to the background gravitational field receives an important modification in quantum theory. In the path integral approach, the manifest covariance of the integral measure under general coordinate transformations dictates that field variables with weight 1/2 should be used as independent integration variables. An improved energy-momentum tensor is then generated by the variational derivative, and it gives rise to well-defined gravitational conformal (Weyl) anomalies. In the flat space-time limit, all the Ward-Takahashi identities associate with space-time transformations including the global dilatation become free from anomalies, reflecting the general covariance of the integral measure; the trace of this energy-momentum tensor is thus finite at the zero momentum transfer. The Jacobian for the local conformal transformation however becomes non-trivial, and it gives rise to an anomaly for the conformal identity. All the familiar anomalies are thus reduced to either chiral or conformal anomalies. The consistency of the dilatation and conformal identities at the vanishing momentum transfer determines the trace anomaly of this energy-momentum tensor in terms of the renormalization group β-function and other parameters. In contrast, the trace of the conventional energy-momentum tensor generally diverges even at the vanishing momentum transfer depending on the regularization scheme, and it is subtractively renormalized. We also explain how the apparently different renormalization properties of the chiral and trace anomalies arise. (author)

  8. Noncommutative gauge field theories: A no-go theorem

    International Nuclear Information System (INIS)

    Chaichian, M.; Tureanu, A.; Presnajder, P.; Sheikh-Jabbari, M.M.

    2001-06-01

    Studying the mathematical structure of the noncommutative groups in more detail, we prove a no-go theorem for the noncommutative gauge theories. According to this theorem, the closure condition of the gauge algebra implies that: 1) the local noncommutative u(n) algebra only admits the irreducible nxn matrix-representation. Hence the gauge fields, as elements of the algebra, are in nxn matrix form, while the matter fields can only be either in fundamental, adjoint or singlet states; 2) for any gauge group consisting of several simple group factors, the matter fields can transform nontrivially under at most two noncommutative group factors. In other words, the matter fields cannot carry more than two simple noncommutative gauge group charges. This no-go theorem imposes strong restrictions on the construction of the noncommutative version of the Standard Model and in resolving the standing problem of charge quantization in noncommutative QED. (author)

  9. Blockspin transformations for finite temperature field theories with gauge fields

    International Nuclear Information System (INIS)

    Kerres, U.

    1996-08-01

    A procedure is proposed to study quantum field theories at zero or at finite temperature by a sequence of real space renormalization group (RG) or blockspin transformations. They transform to effective theories on coarser and coarser lattices. The ultimate aim is to compute constraint effective potentials, i.e. the free energy as a function of suitable order parameters. From the free energy one can read off the thermodynamic behaviour of the theory, in particular the existence and nature of phase transitions. In a finite temperature field theory one begins with either one or a sequence of transformations which transform the original theory into an effective theory on a three-dimensional lattice. Its effective action has temperature dependent coefficients. Thereafter one may proceed with further blockspin transformations of the three-dimensional theory. Assuming a finite volume, this can in principle be continued until one ends with a lattice with a single site. Its effective action is the constraint effective potential. In each RG-step, an integral over the high frequency part of the field, also called the fluctuation field, has to be performed. This is done by perturbation theory. It requires the knowledge of bare fluctuation field propagators and of interpolation operators which enter into the vertices. A detailed examination of these quantities is presented for scalar fields, abelian gauge fields and for Higgs fields, finite temperature is admitted. The lattice perturbation theory is complicated because the bare lattice propagators are complicated. This is due to a partial loss of translation invariance in each step. Therefore the use of translation invariant cutoffs in place of a lattice is also discussed. In case of gauge fields this is only possible as a continuum version of the blockspin method. (orig.)

  10. Tensor Fields for Use in Fractional-Order Viscoelasticity

    Science.gov (United States)

    Freed, Alan D.; Diethelm, Kai

    2003-01-01

    To be able to construct viscoelastic material models from fractional0order differentegral equations that are applicable for 3D finite-strain analysis requires definitions for fractional derivatives and integrals for symmetric tensor fields, like stress and strain. We define these fields in the body manifold. We then map them ito spatial fields expressed in terms of an Eulerian or Lagrangian reference frame where most analysts prefer to solve boundary problems.

  11. Torsion tensor and covector in a unified field theory

    International Nuclear Information System (INIS)

    Chernikov, N.A.

    1976-01-01

    The Einstein unified field theory is used to solve a tensor equation to provide the unambiguous definition of affine connectedness. In the process of solving the Einstein equation limitations imposed by symmetry on the tensor and the torsion covector as well as on affine connectedness are elucidated. It is demonstrated that in a symmetric case the connectedness is unambiguously determined by the Einstein equation. By means of the Riemann geometry a formula for the torsion covector is derived. The equivalence of Einstein equations to those of the nonlinear Born-Infeld electrodynamics is proved

  12. Manipulating novel quantum phenomena using synthetic gauge fields

    Science.gov (United States)

    Zhang, Shao-Liang; Zhou, Qi

    2017-11-01

    The past few years have seen fascinating progress in the creation and utilization of synthetic gauge fields for charge-neutral ultracold atoms. Whereas the synthesis of gauge fields in itself is readily interesting, it is more exciting to explore the new era that will be brought by the interplay between synthetic gauge fields and many other degrees of freedom of highly tunable ultracold atoms. This topical review surveys recent developments in using synthetic gauge fields to manipulate novel quantum phenomena that are not easy to access in other systems. We first summarize current experimental methods of creating synthetic gauge fields, including the use of Raman schemes, shaken lattices, and Raman-dressed lattices. We then discuss how synthetic gauge fields bring new physics to non-interacting systems, including degenerate single-particle ground states, quartic dispersions, topological band structures in lattices, and synthetic dimensions. As for interacting systems, we focus on novel quantum many-body states and quantum macroscopic phenomena induced by interactions in the presence of unconventional single-particle dispersions. For bosons, we discuss how a quartic dispersion leads to non-condensed bosonic states at low temperatures and at the ground state. For fermions, we discuss chiral superfluids in the presence of attractive s-wave interaction, where high partial-wave interactions are not required. Finally, we discuss the challenges in current experiments, and conclude with an outlook for what new exciting developments synthetic gauge fields may bring us in the near future.

  13. Massive Abelian gauge fields coupled with nonconserved currents

    International Nuclear Information System (INIS)

    Nakazato, Hiromichi; Namiki, Mikio; Yamanaka, Yoshiya; Yokoyama, Kan-ichi.

    1985-04-01

    A massive Abelian gauge field coupled with a nonconserved mass-changing current is described within the framework of canonical quantum theory with indefinite metric. In addition to the conventional Lagrange multiplier fields, another ghost field is introduced to preserve gauge invariance and unitarity of a physical S-matrix in the case of the nonconserved current. The renormalizability of the theory is explicitly shown in the sense of superpropagator approach for nonpolynomial Lagrangian theories. (author)

  14. A new deteriorated energy-momentum tensor

    International Nuclear Information System (INIS)

    Duff, M.J.

    1982-01-01

    The stress-tensor of a scalar field theory is not unique because of the possibility of adding an 'improvement term'. In supersymmetric field theories the stress-tensor will appear in a super-current multiplet along with the sypersymmetry current. The general question of the supercurrent multiplet for arbitrary deteriorated stress tensors and their relationship to supercurrent multiplets for models with gauge antisymmetric tensors is answered for various models of N = 1, 2 and 4 supersymmetry. (U.K.)

  15. Extended monopoles in gauge field theories

    International Nuclear Information System (INIS)

    Horvath, Z.; Palla, L.

    1977-04-01

    The paper gives a review of the 't Hooft monopole and briefly discusses the general topological considerations connected with monopoles. A method is presented for constructing explicit monopole solutions in any gauge theory. Some stability questions and time-dependent problems are also considered

  16. Dilaton and second-rank tensor fields as supersymmetric compensators

    International Nuclear Information System (INIS)

    Nishino, Hitoshi; Rajpoot, Subhash

    2007-01-01

    We formulate a supersymmetric theory in which both a dilaton and a second-rank tensor play roles of compensators. The basic off-shell multiplets are a linear multiplet (B μν ,χ,φ) and a vector multiplet (A μ ,λ;C μνρ ), where φ and B μν are, respectively, a dilaton and a second-rank tensor. The third-rank tensor C μνρ in the vector multiplet is ''dual'' to the conventional D field with 0 on-shell or 1 off-shell degree of freedom. The dilaton φ is absorbed into one longitudinal component of A μ , making it massive. Initially, B μν has 1 on-shell or 3 off-shell degrees of freedom, but it is absorbed into the longitudinal components of C μνρ . Eventually, C μνρ with 0 on-shell or 1 off-shell degree of freedom acquires in total 1 on-shell or 4 off-shell degrees of freedom, turning into a propagating massive field. These basic multiplets are also coupled to chiral multiplets and a supersymmetric Dirac-Born-Infeld action. Some of these results are also reformulated in superspace. The proposed mechanism may well provide a solution to the long-standing puzzle of massless dilatons and second-rank tensors in supersymmetric models inspired by string theory

  17. Two-time physics with gravitational and gauge field backgrounds

    International Nuclear Information System (INIS)

    Bars, Itzhak

    2000-01-01

    It is shown that all possible gravitational, gauge and other interactions experienced by particles in ordinary d dimensions (one time) can be described in the language of two-time physics in a spacetime with d+2 dimensions. This is obtained by generalizing the world line formulation of two-time physics by including background fields. A given two-time model, with a fixed set of background fields, can be gauged fixed from d+2 dimensions to (d-1)+1 dimensions to produce diverse one-time dynamical models, all of which are dually related to each other under the underlying gauge symmetry of the unified two-time theory. To satisfy the gauge symmetry of the two-time theory the background fields must obey certain coupled differential equations that are generally covariant and gauge invariant in the target (d+2)-dimensional spacetime. The gravitational background obeys a closed homothety condition while the gauge field obeys a differential equation that generalizes a similar equation derived by Dirac in 1936. Explicit solutions to these coupled equations show that the usual gravitational, gauge, and other interactions in d dimensions may be viewed as embedded in the higher (d+2)-dimensional space, thus displaying higher spacetime symmetries that otherwise remain hidden

  18. Gauge fields in algebraically special space-times

    International Nuclear Information System (INIS)

    Torres del Castillo, G.F.

    1985-01-01

    It is shown that in an algebraically special space-time which admits a congruence of null strings, a source-free gauge field aligned with the congruence is determined by a matrix potential which has to satisfy a second-order differential equation with quadratic nonlinearities. The Einstein--Yang--Mills equations are then reduced to a scalar and two matrix equations. In the case of self-dual gauge fields in a self-dual space-time, the existence of an infinite set of conservation laws, of an associated linear system, and of infinitesimal Baecklund transformations is demonstrated. All the results apply for an arbitrary gauge group

  19. Hot gauge field properties from the thermal variational principle

    International Nuclear Information System (INIS)

    Schroeder, Y.; Schulz, H.

    1995-10-01

    A Feynman-Jensen version of the thermal variational principle is applied to hot gauge fields, abelian as well as nonabelian: scalar electrodynamics (without scalar self-coupling) and the gluon plasma. The perturbatively known self-energies are shown to derive by variation from a free quadratic (''gaussian'') trial Lagrangian. Independence of the covariant gauge fixing parameter is reached (within the order g 2 studies and for scalar ED) after a reformulation of the partition function such that it depends on only even powers of the gauge field. This way, however, the potential non-perturbative power of the calculus seems to be ruined. (orig.)

  20. Nonlocal gauge theories

    International Nuclear Information System (INIS)

    Partovi, M.H.

    1982-01-01

    From a generalization of the covariant derivative, nonlocal gauge theories are developed. These theories enjoy local gauge invariance and associated Ward identities, a corresponding locally conserved current, and a locally conserved energy-momentum tensor, with the Ward identities implying the masslessness of the gauge field as in local theories. Their ultraviolet behavior allows the presence as well as the absence of the Adler-Bell-Jackiw anomaly, the latter in analogy with lattice theories

  1. Dual geometric-gauge field aspects of gravity

    International Nuclear Information System (INIS)

    Huei Peng; Wang, K.

    1992-01-01

    We propose that the geometric and standard gauge field aspects of gravity are equally essential for a complete description of gravity and can be reconciled. We show that this dualism of gravity resolves the dimensional Newtonian constant problem in both quantum gravity and unification schemes involving gravity (i.e., the Newtonian constant is no longer the coupling constant in the gauge aspect of gravity) and reveals the profound similarity between gravity and other fields. 23 refs., 3 tabs

  2. On quantization of the electromagnetic field in radiation gauge

    International Nuclear Information System (INIS)

    Burzynski, A.

    1982-01-01

    This paper contains a detailed description of quantization of the electromagnetic field (in radiation gauge) and quantization of some basic physical variables connected with radiation field as energy, momentum and spin. The dynamics of the free quantum radiation field and the field interacting with external classical sources is described. The canonical formalism is not used explicity. (author)

  3. Near-field photon wave mechanics in the Lorenz gauge

    International Nuclear Information System (INIS)

    Keller, Ole

    2007-01-01

    Optical near-field interactions are studied theoretically in the perspective of photon wave mechanics paying particular attention to the dynamics in the wave-vector time domain. A unitary transformation is used to replace the scalar and longitudinal photon variables by so-called near-field and gauge photon variables. Dynamical equations are established for these types of photon variables, and it is shown that these equations are invariant against gauge transformations within the Lorenz gauge. The near-field photon is absent in the free-field limit, and the gauge photon can be eliminated by a suitable gauge transformation. Implicit solutions for the near-field, gauge, and transverse photon variables are obtained and discussed. The general theory is applied to an investigation of transverse photon propagation in a uniform solid-state plasma dominated by the diamagnetic field-matter interaction. It is found that the diamagnetic response can be incorporated in a quantum mechanical wave equation for a massive transverse photon. The Compton wave number of the massive photon equals the plasma wave number of the electron system. A dynamical equation describing the emission of a massive transverse photon from a mesoscopic source embedded in the plasma is finally established

  4. From 6D superconformal field theories to dynamic gauged linear sigma models

    Science.gov (United States)

    Apruzzi, Fabio; Hassler, Falk; Heckman, Jonathan J.; Melnikov, Ilarion V.

    2017-09-01

    Compactifications of six-dimensional (6D) superconformal field theories (SCFTs) on four- manifolds generate a large class of novel two-dimensional (2D) quantum field theories. We consider in detail the case of the rank-one simple non-Higgsable cluster 6D SCFTs. On the tensor branch of these theories, the gauge group is simple and there are no matter fields. For compactifications on suitably chosen Kähler surfaces, we present evidence that this provides a method to realize 2D SCFTs with N =(0 ,2 ) supersymmetry. In particular, we find that reduction on the tensor branch of the 6D SCFT yields a description of the same 2D fixed point that is described in the UV by a gauged linear sigma model (GLSM) in which the parameters are promoted to dynamical fields, that is, a "dynamic GLSM" (DGLSM). Consistency of the model requires the DGLSM to be coupled to additional non-Lagrangian sectors obtained from reduction of the antichiral two-form of the 6D theory. These extra sectors include both chiral and antichiral currents, as well as spacetime filling noncritical strings of the 6D theory. For each candidate 2D SCFT, we also extract the left- and right-moving central charges in terms of data of the 6D SCFT and the compactification manifold.

  5. Remarks on an equation common to Weyl's gauge field, Yang-Mills field and Toda lattice

    International Nuclear Information System (INIS)

    Nishioka, M.

    1984-01-01

    In this letter a remark is presented on an equation of a gauge-invariant Weyl's gauge field and it is shown that the equation is common to Yang's approach to the self-duality condition for SU 2 gauge field and the simplest Toda lattice

  6. Hyperunified field theory and gravitational gauge-geometry duality

    International Nuclear Information System (INIS)

    Wu, Yue-Liang

    2018-01-01

    A hyperunified field theory is built in detail based on the postulates of gauge invariance and coordinate independence along with the conformal scaling symmetry. All elementary particles are merged into a single hyper-spinor field and all basic forces are unified into a fundamental interaction governed by the hyper-spin gauge symmetry SP(1, D h - 1). The dimension D h of hyper-spacetime is conjectured to have a physical origin in correlation with the hyper-spin charge of elementary particles. The hyper-gravifield fiber bundle structure of biframe hyper-spacetime appears naturally with the globally flat Minkowski hyper-spacetime as a base spacetime and the locally flat hyper-gravifield spacetime as a fiber that is viewed as a dynamically emerged hyper-spacetime characterized by a non-commutative geometry. The gravitational origin of gauge symmetry is revealed with the hyper-gravifield that plays an essential role as a Goldstone-like field. The gauge-gravity and gravity-geometry correspondences bring about the gravitational gauge-geometry duality. The basic properties of hyperunified field theory and the issue on the fundamental scale are analyzed within the framework of quantum field theory, which allows us to describe the laws of nature in deriving the gauge gravitational equation with the conserved current and the geometric gravitational equations of Einstein-like type and beyond. (orig.)

  7. Hyperunified field theory and gravitational gauge-geometry duality

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Yue-Liang [International Centre for Theoretical Physics Asia-Pacific (ICTP-AP), Beijing (China); Chinese Academy of Sciences, Institute of Theoretical Physics, Beijing (China); University of Chinese Academy of Sciences (UCAS), Beijing (China)

    2018-01-15

    A hyperunified field theory is built in detail based on the postulates of gauge invariance and coordinate independence along with the conformal scaling symmetry. All elementary particles are merged into a single hyper-spinor field and all basic forces are unified into a fundamental interaction governed by the hyper-spin gauge symmetry SP(1, D{sub h} - 1). The dimension D{sub h} of hyper-spacetime is conjectured to have a physical origin in correlation with the hyper-spin charge of elementary particles. The hyper-gravifield fiber bundle structure of biframe hyper-spacetime appears naturally with the globally flat Minkowski hyper-spacetime as a base spacetime and the locally flat hyper-gravifield spacetime as a fiber that is viewed as a dynamically emerged hyper-spacetime characterized by a non-commutative geometry. The gravitational origin of gauge symmetry is revealed with the hyper-gravifield that plays an essential role as a Goldstone-like field. The gauge-gravity and gravity-geometry correspondences bring about the gravitational gauge-geometry duality. The basic properties of hyperunified field theory and the issue on the fundamental scale are analyzed within the framework of quantum field theory, which allows us to describe the laws of nature in deriving the gauge gravitational equation with the conserved current and the geometric gravitational equations of Einstein-like type and beyond. (orig.)

  8. Hyperunified field theory and gravitational gauge-geometry duality

    Science.gov (United States)

    Wu, Yue-Liang

    2018-01-01

    A hyperunified field theory is built in detail based on the postulates of gauge invariance and coordinate independence along with the conformal scaling symmetry. All elementary particles are merged into a single hyper-spinor field and all basic forces are unified into a fundamental interaction governed by the hyper-spin gauge symmetry SP(1, D_h-1). The dimension D_h of hyper-spacetime is conjectured to have a physical origin in correlation with the hyper-spin charge of elementary particles. The hyper-gravifield fiber bundle structure of biframe hyper-spacetime appears naturally with the globally flat Minkowski hyper-spacetime as a base spacetime and the locally flat hyper-gravifield spacetime as a fiber that is viewed as a dynamically emerged hyper-spacetime characterized by a non-commutative geometry. The gravitational origin of gauge symmetry is revealed with the hyper-gravifield that plays an essential role as a Goldstone-like field. The gauge-gravity and gravity-geometry correspondences bring about the gravitational gauge-geometry duality. The basic properties of hyperunified field theory and the issue on the fundamental scale are analyzed within the framework of quantum field theory, which allows us to describe the laws of nature in deriving the gauge gravitational equation with the conserved current and the geometric gravitational equations of Einstein-like type and beyond.

  9. Nambu–Poisson gauge theory

    Energy Technology Data Exchange (ETDEWEB)

    Jurčo, Branislav, E-mail: jurco@karlin.mff.cuni.cz [Charles University in Prague, Faculty of Mathematics and Physics, Mathematical Institute, Prague 186 75 (Czech Republic); Schupp, Peter, E-mail: p.schupp@jacobs-university.de [Jacobs University Bremen, 28759 Bremen (Germany); Vysoký, Jan, E-mail: vysokjan@fjfi.cvut.cz [Jacobs University Bremen, 28759 Bremen (Germany); Czech Technical University in Prague, Faculty of Nuclear Sciences and Physical Engineering, Prague 115 19 (Czech Republic)

    2014-06-02

    We generalize noncommutative gauge theory using Nambu–Poisson structures to obtain a new type of gauge theory with higher brackets and gauge fields. The approach is based on covariant coordinates and higher versions of the Seiberg–Witten map. We construct a covariant Nambu–Poisson gauge theory action, give its first order expansion in the Nambu–Poisson tensor and relate it to a Nambu–Poisson matrix model.

  10. Nambu–Poisson gauge theory

    International Nuclear Information System (INIS)

    Jurčo, Branislav; Schupp, Peter; Vysoký, Jan

    2014-01-01

    We generalize noncommutative gauge theory using Nambu–Poisson structures to obtain a new type of gauge theory with higher brackets and gauge fields. The approach is based on covariant coordinates and higher versions of the Seiberg–Witten map. We construct a covariant Nambu–Poisson gauge theory action, give its first order expansion in the Nambu–Poisson tensor and relate it to a Nambu–Poisson matrix model.

  11. Theoretical Maxwell's Equations, Gauge Field and Their Universality Based on One Conservation Law

    Institute of Scientific and Technical Information of China (English)

    Liu Changmao

    2005-01-01

    The notion of the inner product of vectors is extended to tensors of different orders, which may replace the vector product usually. The essences of the differential and the codifferential forms are pointed out: they represent the tangent surface and the normal surface fluxes of a tensor, respectively. The definitions of the divergence and the curl of a 2D surface flux of a tensor are obtained.Maxwell's equations, namely, the construction law of field, which were usually established based on two conservation laws of electric charge and imaginary magnetic charge, are derived by the author only by using one conservation law ( mass or fluid flux quantity and so on) and the feature of central field ( or its composition). By the feature of central field ( or its composition), the curl of 2D flux is zero. Both universality of gauge field and the difficulty of magnetic monopole theory ( a magnetic monopole has no effect on electric current just like a couple basing no effect on the sum of forces) are presented: magnetic monopole has no the feature of magnet. Finally it is pointed out that the base of relation of mass and energy is already involved in Maxwell's equations.

  12. The Schouten tensor as a connection in the unfolding of 3D conformal higher-spin fields

    Energy Technology Data Exchange (ETDEWEB)

    Basile, Thomas [Group of Mechanics and Gravitation, Physique théorique et mathématique,University of Mons - UMONS,20 Place du Parc, 7000 Mons (Belgium); Laboratoire de Mathématiques et Physique Théorique, Unité Mixte de Recherche du CNRS,Fédération de Recherche Denis Poisson, Université François Rabelais, Parc de Grandmont, 37200 Tours (France); Bonezzi, Roberto; Boulanger, Nicolas [Group of Mechanics and Gravitation, Physique théorique et mathématique,University of Mons - UMONS,20 Place du Parc, 7000 Mons (Belgium)

    2017-04-11

    A first-order differential equation is provided for a one-form, spin-s connection valued in the two-row, width-(s−1) Young tableau of GL(5). The connection is glued to a zero-form identified with the spin-s Cotton tensor. The usual zero-Cotton equation for a symmetric, conformal spin-s tensor gauge field in 3D is the flatness condition for the sum of the GL(5) spin-s and background connections. This presentation of the equations allows to reformulate in a compact way the cohomological problem studied in https://arxiv.org/abs/1511.07389, featuring the spin-s Schouten tensor. We provide full computational details for spin 3 and 4 and present the general spin-s case in a compact way.

  13. Lattice Gauge Field Theory and Prismatic Sets

    DEFF Research Database (Denmark)

    Akyar, Bedia; Dupont, Johan Louis

    as and in particular the latter we use to study lattice gauge theory in the sense of Phillips and Stone. Thus for a Lie group and a set of parallel transport functions defining the transition over faces of the simplices, we define a classifying map from the prismatic star to a prismatic version of the classifying......We study prismatic sets analogously to simplicial sets except that realization involves prisms, i.e., products of simplices rather than just simplices. Particular examples are the prismatic subdivision of a simplicial set and the prismatic star of . Both have the same homotopy type...

  14. 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

  15. Currents and the energy-momentum tensor in classical field theory: a fresh look at an old problem

    International Nuclear Information System (INIS)

    Forger, Michael; Roemer, Hartmann

    2004-01-01

    We give a comprehensive review of various methods to define currents and the energy-momentum tensor in classical field theory, with emphasis on a geometric point of view. The necessity of 'improving' the expressions provided by the canonical Noether procedure is addressed and given an adequate geometric framework. The main new ingredient is the explicit formulation of a principle of 'ultralocality' with respect to the symmetry generators, which is shown to fix the ambiguity inherent in the procedure of improvement and guide it towards a unique answer: when combined with the appropriate splitting of the fields into sectors, it leads to the well-known expressions for the current as the variational derivative of the matter field Lagrangian with respect to the gauge field and for the energy-momentum tensor as the variational derivative of the matter field Lagrangian with respect to the metric tensor. In the second case, the procedure is shown to work even when the matter field Lagrangian depends explicitly on the curvature, thus establishing the correct relation between scale invariance, in the form of local Weyl invariance 'on shell', and tracelessness of the energy-momentum tensor, required for a consistent definition of the concept of a conformal field theory

  16. Meta fluid dynamic as a gauge field theory

    International Nuclear Information System (INIS)

    Mendes, A.C.R.; Neves, C.; Oliveira, W.; Takakura, F.I.

    2003-01-01

    In this paper, the analog of Maxwell electromagnetism for hydrodynamic turbulence, the meta fluid dynamics, is extended in order to reformulate the meta fluid dynamics as a gauge field theory. That analogy opens up the possibility to investigate this theory as a constrained system. Having this possibility in mind, we propose a Lagrangian to describe this new theory of turbulence and, subsequently, analyze it from the symplectic point of view. From this analysis, a hidden gauge symmetry is revealed, providing a clear interpretation and meaning of the physics behind the meta fluid theory. Also, the geometrical interpretation to the gauge symmetries is discussed. (author)

  17. Inflationary dynamics of kinetically-coupled gauge fields

    DEFF Research Database (Denmark)

    Ferreira, Ricardo J. Z.; Ganc, Jonathan

    2015-01-01

    We investigate the inflationary dynamics of two kinetically-coupled massless U(1) gauge fields with time-varying kinetic-term coefficients. Ensuring that the system does not have strongly coupled regimes shrinks the parameter space. Also, we further restrict ourselves to systems that can be quant......We investigate the inflationary dynamics of two kinetically-coupled massless U(1) gauge fields with time-varying kinetic-term coefficients. Ensuring that the system does not have strongly coupled regimes shrinks the parameter space. Also, we further restrict ourselves to systems that can...... be quantized using the standard creation, annihilation operator algebra. This second constraint limits us to scenarios where the system can be diagonalized into the sum of two decoupled, massless, vector fields with a varying kinetic-term coefficient. Such a system might be interesting for magnetogenesis...... because of how the strong coupling problem generalizes. We explore this idea by assuming that one of the gauge fields is the Standard Model U(1) field and that the other dark gauge field has no particles charged under its gauge group. We consider whether it would be possible to transfer a magnetic field...

  18. Interaction of orientable object fields with gauge fields

    International Nuclear Information System (INIS)

    Gitman, D M; Shelepin, A L

    2011-01-01

    We consider a scalar field f(g) on the Poincaré group M(3, 1). This scalar field describes objects that are characterized by a position x and an orientation z, g=(x,z). The field f(x, z) admits two kinds of transformations, corresponding to a change of the space-fixed reference frame, as well as to a change of the body-fixed reference frame, which form the group M(3, 1) ext ×M(3, 1) int , and also phase transformations U(1) ch of orientational variables z. Elementary particles considered as elementary orientable objects are described by the scalar functions transforming according to irreps of the group M(3, 1) ext ×M(3, 1) int ×U(1) ch . Correspondingly, their continuous symmetries can be divided into external, which form the Poincaré group M(3, 1) ext , and internal M(3, 1) int ×U(1) ch . The assumption that the internal symmetries in the theory of orientable objects are gauge ones allows one to obtain important features of the known fundamental interactions—the electroweak and the gravitational. Localization of the group of the right translations T(4) int leads to the teleparallel theory of gravity, which is equivalent to general relativity. Localization of the compact subgroup SU(2) int ×U(1) ch leads to the theory of electroweak interactions. Thus, the suggested approach can be considered as a possible way to gravitational-electroweak unification.

  19. Gauge field propagator and the number of fermion fields

    International Nuclear Information System (INIS)

    Oehme, R.; Zimmermann, W.

    1980-01-01

    The structure of the transverse gluon propagator D of massless quantum chromodynamics is considered in the Landau gauge. The essential differences in the weak-coupling limit g → 0 for γ 0 /β 0 >0 and γ 0 /β 0 0 and β 0 are coefficients of lowest-order terms of the anomalous dimension and of the β function. For SU(3) as the color group and quark triplets, the corresponding flavor conditions are N/sub F/ 0 /β 0 >0 there are inconsistencies with the postulates of local quantum field theory and the requirement that the positive-norm contribution D/sub +/ to D should approach its free-field value for g → 0. In the present paper, it is investigated in detail how this requirement is violated assuming that the other postulates hold, including invariance under the renormalization group. Using a specific, simple projection into a subspace of positive norm, it is shown that D/sub +/ diverges like (g 2 )/sup -gamma/0/sup /beta/0, while the free-field value and higher-order terms of D are entirely due to contributions from negative-norm states. In contradistinction, the required dominance of positive-norm states in the weak-coupling limit prevails for γ 0 /β 0 2 → 0

  20. Gauge structure of neutral-vector field theory. [Massive vector fields, massless limits

    Energy Technology Data Exchange (ETDEWEB)

    Kubo, R; Yokoyama, [Hiroshima univ., Takehara (Japan). Research Inst. for Theoretical Physics

    1975-03-01

    General aspects of gauge structure of neutral-vector field theory are investigated from an extended standpoint, where massive vector fields are treated in a form corresponding to the electromagnetic fields in a general gauge formalism reported previously. All results obtained are shown to have unique massless limits. It is shown that a generalized q-number gauge transformation for fields makes the theory invariant in cooperation with a simultaneous transformation for relevant gauge parameters. A method of differentiation with respect to a gauge variable is found to clarify some essential features of the gauge structure. Two possible types of gauge structure also emerge correspondingly to the massless case. A neutral-vector field theory proposed in a preceding paper is included in the present framework as the most preferable case.

  1. Multigrid Methods for the Computation of Propagators in Gauge Fields

    Science.gov (United States)

    Kalkreuter, Thomas

    Multigrid methods were invented for the solution of discretized partial differential equations in order to overcome the slowness of traditional algorithms by updates on various length scales. In the present work generalizations of multigrid methods for propagators in gauge fields are investigated. Gauge fields are incorporated in algorithms in a covariant way. The kernel C of the restriction operator which averages from one grid to the next coarser grid is defined by projection on the ground-state of a local Hamiltonian. The idea behind this definition is that the appropriate notion of smoothness depends on the dynamics. The ground-state projection choice of C can be used in arbitrary dimension and for arbitrary gauge group. We discuss proper averaging operations for bosons and for staggered fermions. The kernels C can also be used in multigrid Monte Carlo simulations, and for the definition of block spins and blocked gauge fields in Monte Carlo renormalization group studies. Actual numerical computations are performed in four-dimensional SU(2) gauge fields. We prove that our proposals for block spins are “good”, using renormalization group arguments. A central result is that the multigrid method works in arbitrarily disordered gauge fields, in principle. It is proved that computations of propagators in gauge fields without critical slowing down are possible when one uses an ideal interpolation kernel. Unfortunately, the idealized algorithm is not practical, but it was important to answer questions of principle. Practical methods are able to outperform the conjugate gradient algorithm in case of bosons. The case of staggered fermions is harder. Multigrid methods give considerable speed-ups compared to conventional relaxation algorithms, but on lattices up to 184 conjugate gradient is superior.

  2. Constant self-dual Abelian gauge fields and fermions in SU(2) gauge theory

    International Nuclear Information System (INIS)

    Kay, D.; Parthasarathy, R.; Viswanathan, K.S.

    1983-01-01

    Fermion one-loop corrections to the effective action in a self-dual Abelian background field are calculated for an SU(2) gauge theory. It is found that these corrections for massless fermions tend to destabilize the vacuum. The quantitative and qualitative features of such corrections for the case of massive fermions are discussed

  3. Self-consistent normal ordering of gauge field theories

    International Nuclear Information System (INIS)

    Ruehl, W.

    1987-01-01

    Mean-field theories with a real action of unconstrained fields can be self-consistently normal ordered. This leads to a considerable improvement over standard mean-field theory. This concept is applied to lattice gauge theories. First an appropriate real action mean-field theory is constructed. The equations determining the Gaussian kernel necessary for self-consistent normal ordering of this mean-field theory are derived. (author). 4 refs

  4. Non-Abelian gauge theory of fields associated with dyons

    International Nuclear Information System (INIS)

    Rajput, B.S.; Kumar, S.R.

    1983-01-01

    A suitable Lorentz invariant non-Abelian gauge theory of the fields associated with dyons has been constructed to describe the dual dynamics between colour isocharges and topological charges. It has been shown that the generalized particle current is gauge covariant and not conserved in non-Abelian theory. It has also been shown that in this theory the unphysical string variables and unphysical charged fields are not needed and that any extra constraint to maintain the dual symmetry of field equation and Lagrangian is also not needed. (author)

  5. The first law of black hole mechanics for fields with internal gauge freedom

    International Nuclear Information System (INIS)

    Prabhu, Kartik

    2017-01-01

    We derive the first law of black hole mechanics for physical theories based on a local, covariant and gauge-invariant Lagrangian where the dynamical fields transform non-trivially under the action of some internal gauge transformations. The theories of interest include General Relativity formulated in terms of tetrads, Einstein–Yang–Mills theory and Einstein–Dirac theory. Since the dynamical fields of these theories have some internal gauge freedom, we argue that there is no natural group action of diffeomorphisms of spacetime on such dynamical fields. In general, such fields cannot even be represented as smooth, globally well-defined tensor fields on spacetime. Consequently the derivation of the first law by Iyer and Wald cannot be used directly. Nevertheless, we show how such theories can be formulated on a principal bundle and that there is a natural action of automorphisms of the bundle on the fields. These bundle automorphisms encode both spacetime diffeomorphisms and internal gauge transformations. Using this reformulation we define the Noether charge associated to an infinitesimal automorphism and the corresponding notion of stationarity and axisymmetry of the dynamical fields. We first show that we can define certain potentials and charges at the horizon of a black hole so that the potentials are constant on the bifurcate Killing horizon, giving a generalised zeroth law for bifurcate Killing horizons. We further identify the gravitational potential and perturbed charge as the temperature and perturbed entropy of the black hole which gives an explicit formula for the perturbed entropy analogous to the Wald entropy formula. We then obtain a general first law of black hole mechanics for such theories. The first law relates the perturbed Hamiltonians at spatial infinity and the horizon, and the horizon contributions take the form of a ‘potential times perturbed charge’ term. We also comment on the ambiguities in defining a prescription for the total

  6. Equations of motion of higher-spin gauge fields as a free differential algebra

    International Nuclear Information System (INIS)

    Vasil'ev, M.A.

    1988-01-01

    It is shown that the introduction of auxiliary dynamical variables that generalize the gravitational Weyl tensor permits one to reduce the equations of motion of free massless fields of all spins in the anti-de Sitter O(3,2) space to a form characteristic of free differential algebras. The equations of motion of auxiliary gauge fields introduced previously are modified analogously. Arguments are presented to the effect that the equations of motion of interacting massless fields of all spins should be described in terms of a free differential algebra which is a deformation of a known free differential algebra generated by 1- and 0-forms in the adjoint representation of a nonabelian superalgebra of higher spins and auxiliary fields

  7. General projective relativity and the vector-tensor gravitational field

    International Nuclear Information System (INIS)

    Arcidiacono, G.

    1986-01-01

    In the general projective relativity, the induced 4-dimensional metric is symmetric in three cases, and we obtain the vector-tensor, the scalar-tensor, and the scalar-vector-tensor theories of gravitation. In this work we examine the vector-tensor theory, similar to the Veblen's theory, but with a different physical interpretation

  8. Dynamics of Gauge Fields at High Temperature

    NARCIS (Netherlands)

    Nauta, B.J.

    2000-01-01

    An effective description of dynamical Bose fields is provided by the classical (high-temperature) limit of thermal field theory. The main subject of this thesis is to improve the ensuing classical field theory, that is, to include the dominant quantum corrections and to add counter terms for the

  9. Non-uniqueness of the source for singular gauge fields

    International Nuclear Information System (INIS)

    Lanyi, G.; Pappas, R.

    1977-01-01

    It is shown that the singular Wu-Yang solution for SU(2) gauge fields may be interpreted as due to a point source at the origin. However, the electric or magnetic nature of the source depends on whether one approaches the singularity by means of a 'smeared' potential or a 'smeared' field strength. (Auth.)

  10. Energy momentum tensor in theories with scalar field

    International Nuclear Information System (INIS)

    Joglekar, S.D.

    1992-01-01

    The renormalization of energy momentum tensor in theories with scalar fields and two coupling constants is considered. The need for addition of an improvement term is shown. Two possible forms for the improvement term are: (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. finite function of the renormalized quantities are considered. Four possible model of such theories are (i) Scalar Q.E.D. (ii) Non-Abelian theory with scalars, (iii) Yukawa theory, (iv) A model with two scalars. In all these theories a negative conclusion is established: neither forms for the improvement terms lead to a finite energy momentum tensor. Physically this means that when interaction with external gravity is incorporated in such a model, additional experimental input in the form of root mean square mass radius must be given to specify the theory completely, and the flat space parameters are insufficient. (author). 12 refs

  11. Hotplate precipitation gauge calibrations and field measurements

    Science.gov (United States)

    Zelasko, Nicholas; Wettlaufer, Adam; Borkhuu, Bujidmaa; Burkhart, Matthew; Campbell, Leah S.; Steenburgh, W. James; Snider, Jefferson R.

    2018-01-01

    First introduced in 2003, approximately 70 Yankee Environmental Systems (YES) hotplate precipitation gauges have been purchased by researchers and operational meteorologists. A version of the YES hotplate is described in Rasmussen et al. (2011; R11). Presented here is testing of a newer version of the hotplate; this device is equipped with longwave and shortwave radiation sensors. Hotplate surface temperature, coefficients describing natural and forced convective sensible energy transfer, and radiative properties (longwave emissivity and shortwave reflectance) are reported for two of the new-version YES hotplates. These parameters are applied in a new algorithm and are used to derive liquid-equivalent accumulations (snowfall and rainfall), and these accumulations are compared to values derived by the internal algorithm used in the YES hotplates (hotplate-derived accumulations). In contrast with R11, the new algorithm accounts for radiative terms in a hotplate's energy budget, applies an energy conversion factor which does not differ from a theoretical energy conversion factor, and applies a surface area that is correct for the YES hotplate. Radiative effects are shown to be relatively unimportant for the precipitation events analyzed. In addition, this work documents a 10 % difference between the hotplate-derived and new-algorithm-derived accumulations. This difference seems consistent with R11's application of a hotplate surface area that deviates from the actual surface area of the YES hotplate and with R11's recommendation for an energy conversion factor that differs from that calculated using thermodynamic theory.

  12. Gibbs perturbations of a two-dimensional gauge field

    International Nuclear Information System (INIS)

    Petrova, E.N.

    1981-01-01

    Small Gibbs perturbations of random fields have been investigated up to now for a few initial fields only. Among them there are independent fields, Gaussian fields and some others. The possibility for the investigation of Gibbs modifications of a random field depends essentially on the existence of good estimates for semiinvariants of this field. This is the reason why the class of random fields for which the investigation of Gibbs perturbations with arbitrary potential of bounded support is possible is rather small. The author takes as initial a well-known model: a two-dimensional gauge field. (Auth.)

  13. Local gauge invariant Lagrangeans in classical field theories

    International Nuclear Information System (INIS)

    Grigore, D.R.

    1982-07-01

    We investigate the most general local gauge invariant Lagrangean in the framework of classical field theory. We rederive esentially Utiyama's result with a slight generalization. Our proof makes clear the importance of the so called current conditions, i.e. the requirement that the Noether currents are different from zero. This condition is of importance both in the general motivation for the introduction of the Yang-Mills fields and for the actual proof. Some comments are made about the basic mathematical structure of the problem - the gauge group. (author)

  14. Lattice formulations of supersymmetric gauge theories with matter fields

    International Nuclear Information System (INIS)

    Joseph, Anosh

    2014-12-01

    Certain classes of supersymmetric gauge theories, including the well known N=4 supersymmetric Yang-Mills theory, that takes part in the AdS/CFT correspondence, can be formulated on a Euclidean spacetime lattice using the techniques of exact lattice supersymmetry. Great ideas such as topological field theories, Dirac-Kaehler fermions, geometric discretization all come together to create supersymmetric lattice theories that are gauge-invariant, doubler free, local and exact supersymmetric. We discuss the recent lattice constructions of supersymmetric Yang-Mills theories in two and three dimensions coupled to matter fields in various representations of the color group.

  15. Gauge-independent decoherence models for solids in external fields

    Science.gov (United States)

    Wismer, Michael S.; Yakovlev, Vladislav S.

    2018-04-01

    We demonstrate gauge-invariant modeling of an open system of electrons in a periodic potential interacting with an optical field. For this purpose, we adapt the covariant derivative to the case of mixed states and put forward a decoherence model that has simple analytical forms in the length and velocity gauges. We demonstrate our methods by calculating harmonic spectra in the strong-field regime and numerically verifying the equivalence of the deterministic master equation to the stochastic Monte Carlo wave-function method.

  16. Determining and uniformly estimating the gauge potential corresponding to a given gauge field on M4

    International Nuclear Information System (INIS)

    Mostow, M.; Shnider, S.; Ben-Gurion Univ. of the Negev, Beersheba

    1986-01-01

    In an earlier paper on the field copy problem, we proved that there exists a generic set of connections (gauge potentials) on a principle bundle with a semi-simple structure group over a four-dimensional base manifold for which the connection is uniquely determined by its curvature (gauge field). We conjectured that there exists a smaller, but still generic, set of connections for which the curvature map sending a connection to its curvature admits a continuous inverse with respect to the appropriate function space topologies. The conjecture says, in other words, that restricting to certain generic curvature 2-forms, one can determine and uniformly estimate the connection and its derivatives from the curvature and uniform estimates of its derivatives. In this Letter we give an affirmative answer to the conjecture and show, moreover, that the set of such connections contains an open dense set in the Whitney C ∞ topology. (orig.)

  17. Gauge-invariant charged, monopole and dyon fields in gauge theories

    International Nuclear Information System (INIS)

    Froehlich, J.; Marchetti, P.A.

    1999-01-01

    We propose explicit recipes to construct the Euclidean Green functions of gauge-invariant charged, monopole and dyon fields in four-dimensional gauge theories whose phase diagram contains phases with deconfined electric and/or magnetic charges. In theories with only either abelian electric or magnetic charges, our construction is an Euclidean version of Dirac's original proposal, the magnetic dual of his proposal, respectively. Rigorous mathematical control is achieved for a class of abelian lattice theories. In theories where electric and magnetic charges coexist, our construction of Green functions of electrically or magnetically charged fields involves taking an average over Mandelstam strings or the dual magnetic flux tubes, in accordance with Dirac's flux quantization condition. We apply our construction to 't Hooft-Polyakov monopoles and Julia-Zee dyons. Connections between our construction and the semiclassical approach are discussed

  18. Gauge field theories on a || lattice

    International Nuclear Information System (INIS)

    Burkardt, Matthias

    1999-01-01

    In these notes, the transverse || lattice approach is presented as a means to control the k + →0 divergences in light-front QCD. Technical difficulties of both the canonical compact formulation as well as the non-compact formulation of the || lattice motivate the color-dielectric formulation, where the link fields are linearized

  19. Operation of cold-cathode gauges in high magnetic fields

    International Nuclear Information System (INIS)

    Thomas, S.R. Jr.; Goerz, D.A.; Pickles, W.L.

    1985-01-01

    The Mirror Fusion Test Facility (MFTF-B), under construction at LLNL, requires measurement of the neutral gas density in high magnetic fields near the plasma at several axial regions. This Background Gas Pressure (BGP) diagnostic will help us understand the role of background neutrals in particle and power balance, particularly in the maintenance of the cold halo plasma that shields the hot core plasma from the returning neutrals. It consists of several cold-cathode, magnetron-type gauges stripped of their permanent magnets, and utilizes the MFTF-B ambient B-field in strengths of 5 to 25 kG. Similar gauges have operated in TMX-U in B-fields up to 3 kG. To determine how well the gauges will perform, we assembled a test stand which operated magnetron gauges in an external, uniform magnetic field of up to 30 kG, over a pressure range of 1E-8 T to 1E-5 T, at several cathode voltages. This paper describes the test stand and presents the results of the tests

  20. Gauge field back reaction on a black hole

    International Nuclear Information System (INIS)

    Hochberg, D.; Kephart, T.W.

    1993-01-01

    The order-ℎ fluctuations of gauge fields in the vicinity of a black hole can create a repulsive antigravity region extending out beyond the renormalized Schwarzschild horizon. If the strength of this repulsive force increases as higher orders in the back reaction are included, the formation of a wormholelike object could occur

  1. Gauge field governing parallel transport along mixed states

    International Nuclear Information System (INIS)

    Uhlmann, A.

    1990-01-01

    At first a short account is given of some basic notations and results on parallel transport along mixed states. A new connection form (gauge field) is introduced to give a geometric meaning to the concept of parallelity in the theory of density operators. (Author) 11 refs

  2. On classical solutions of SU(3) gauge field equations

    International Nuclear Information System (INIS)

    Chakrabarti, A.

    1975-01-01

    Static classical solutions of SU(3) gauge field equations are studied. The roles of the O(3) subgroup and of the quadrupole generators are discussed systematically. The general form thus obtained leads, through-out, to a high degree of symmetry in the results. This brings in some simplifying features. An octet of scalar mesons is finally added. Certain classes of exact solutions are given that are singular at the origin. A generalized gauge condition is pointed out. The relation of the general form to known particular cases is discussed [fr

  3. Interplay between topology, gauge fields and gravity

    Science.gov (United States)

    Corichi Rodriguez Gil, Alejandro

    In this thesis we consider several physical systems that illustrate an interesting interplay between quantum theory, connections and knot theory. It can be divided into two parts. In the first one, we consider the quantization of the free Maxwell field. We show that there is an important role played by knot theory, and in particular the Gauss linking number, in the quantum theory. This manifestation is twofold. The first occurs at the level of the algebra of observables given by fluxes of electric and magnetic field across surfaces. The commutator of the operators, and thus the basic uncertainty relations, are given in terms of the linking number of the loops that bound the surfaces. Next, we consider the quantization of the Maxwell field based on self-dual connections in the loop representation. We show that the measure which determines the quantum inner product can be expressed in terms of the self linking number of thickened loops. Therefore, the linking number manifests itself at two key points of the theory: the Heisenberg uncertainty principle and the inner product. In the second part, we bring gravity into play. First we consider quantum test particles on certain stationary space-times. We demonstrate that a geometric phase exists for those space-times and focus on the example of a rotating cosmic string. The geometric phase can be explicitly computed, providing a fully relativistic gravitational Aharonov-Bohm effect. Finally, we consider 3-dimensional gravity with non-vanishing cosmological constant in the connection dynamics formulation. We restrict our attention to Lorentzian gravity with positive cosmological constant and Euclidean signature with negative cosmological constant. A complex transformation is performed in phase space that makes the constraints simple. The reduced phase space is characterized as the moduli space of flat complex connections. We construct the quantization of the theory when the initial hyper-surface is a torus. Two important

  4. 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.

  5. Erratum to Surface‐wave green’s tensors in the near field

    Science.gov (United States)

    Haney, Matthew M.; Hisashi Nakahara,

    2016-01-01

    Haney and Nakahara (2014) derived expressions for surface‐wave Green’s tensors that included near‐field behavior. Building on the result for a force source, Haney and Nakahara (2014) further derived expressions for a general point moment tensor source using the exact Green’s tensors. However, it has come to our attention that, although the Green’s tensors were correct, the resulting expressions for a general point moment tensor source were missing some terms. In this erratum, we provide updated expressions with these missing terms. The inclusion of the missing terms changes the example given in Haney and Nakahara (2014).

  6. Measurement of gravity and gauge fields using quantum mechanical probes

    International Nuclear Information System (INIS)

    Anandan, J.

    1986-01-01

    The author considers the question of which quantities are observed when the gravitational and gauge fields are measured by a quantum mechanical probe. The motion of a quantum mechanical particle can be constructed, via Huyghens' principle, by the interference of secondary wavelets. Three types of interference phenomena are considered: interference of two coherent beams separated in space-time during part of their motion; interference of two coherent beams which are in the same region in spacetime but differ in energy or mass; and the Josphson effect and its generalization. The author shows how to determine the gravitational field by means of quantum interference. The corresponding problem for gauge fields is treated and a simple proof of the previously proved theorem for the reconstruction of the connection from the holonomy transformations is presented. A heuristic principle for the gravitational interaction of two quantum mechanical particles is formulated which implies the equivalence of inertial and active gravitational masses

  7. Strong coupling in a gauge invariant field theory

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, K. [Physics Department, Massachusetts Institute of Technology, Cambridge, MA (United States)

    1963-01-15

    I would like to discuss some approximations which may be significant in the domain of strong coupling in a field system analogous to quantum electrodynamics. The motivation of this work is the idea that the strong couplings and elementary particle spectrum may be the consequence of the dynamics of a system whose underlying description is in terms of a set of Fermi fields gauge invariantly coupled to a single (''bare'') massless neutral vector field. The basis of this gauge invariance would of course be the exact conservation law of baryons or ''nucleonic charge''. It seems to me that a coupling scheme based on an invariance principle is most attractive if that invariance is an exact one. It would then be nice to try to account for the approximate invariance principles in the same way one would describe ''accidental degeneracies'' in any quantum system.

  8. Broken Weyl symmetry. [Gauge model, coupling, Higgs field

    Energy Technology Data Exchange (ETDEWEB)

    Domokos, G.

    1976-05-01

    It is argued that conformal symmetry can be properly understood in the framework of field theories in curved space. In such theories, invariance is required under general coordinate transformations and conformal rescalings. A gauge model coupled to a Higgs field is examined. In the tree approximation, the vacuum solution exhibits two Higgs phenomena; both the phase (Goldstone boson) and the coordinate dependent part of the radial component of the scalar field can be removed by a Higgs-Kibble transformation. The resulting vacuum solution corresponds to a space of constant curvature and constant vacuum expectation value of the scalar field.

  9. A gauge quantum field theory of confined quarks and gluons

    International Nuclear Information System (INIS)

    Voelkel, A.H.

    1983-01-01

    A SU(3)-gauge quantum field theory with a quark triplet, an antiquark triplet and a self-conjugate gluon octet as basic fields is investigated. In virtue of a non trivial coupling between the representation of the translation group and the SU(3)-colour charge of the basic fields it is proved: (i) The basic quark, antiquark and gluon fields are confined. (ii) Every statevector of the physical Hilbert space is a SU(3)-colour singlet state. (iii) Poincare invariance holds in the physical Hilbert space. (orig.)

  10. The extended local gauge invariance and the BRS symmetry in stochastic quantization of gauge fields

    International Nuclear Information System (INIS)

    Nakazawa, Naohito.

    1989-05-01

    We investigate the BRS invariance of the first-class constrained systems in the context of the stochastic quantization. For the first-class constrained systems, we construct the nilpotent BRS transformation and the BRS invariant stochastic effective action based on the D+1 dimensional field theoretical formulation of stochastic quantization. By eliminating the multiplier field of the gauge fixing condition and an auxiliary field, it is shown that there exists a truncated BRS transformation which satisfies the nilpotency condition. The truncated BRS invariant stochastic action is also derived. As the examples of the general formulation, we investigate the BRS invariant structure in the massless and massive Yang-Mills fields in stochastic quantization. (author)

  11. Enhanced gauge symmetry and winding modes in double field theory

    Energy Technology Data Exchange (ETDEWEB)

    Aldazabal, G. [Centro Atómico Bariloche,8400 S.C. de Bariloche (Argentina); Instituto Balseiro (CNEA-UNC) and CONICET,8400 S.C. de Bariloche (Argentina); Graña, M. [Institut de Physique Théorique, CEA/ Saclay,91191 Gif-sur-Yvette Cedex (France); Iguri, S. [Instituto de Astronomía y Física del Espacio (CONICET-UBA), Universidad de Buenos Aires,1428 Buenos Aires (Argentina); Mayo, M. [Centro Atómico Bariloche,8400 S.C. de Bariloche (Argentina); Instituto Balseiro (CNEA-UNC) and CONICET,8400 S.C. de Bariloche (Argentina); Nuñez, C. [Instituto de Astronomía y Física del Espacio (CONICET-UBA), Universidad de Buenos Aires,1428 Buenos Aires (Argentina); Departamento de Física, FCEN, Universidad de Buenos Aires,C.C. 67 - Suc. 28, 1428 Buenos Aires (Argentina); Rosabal, J.A. [Departamento de Física, FCEN, Universidad de Buenos Aires,C.C. 67 - Suc. 28, 1428 Buenos Aires (Argentina)

    2016-03-15

    We provide an explicit example of how the string winding modes can be incorporated in double field theory. Our guiding case is the closed bosonic string compactified on a circle of radius close to the self-dual point, where some modes with non-zero winding or discrete momentum number become massless and enhance the U(1)×U(1) symmetry to SU(2)×SU(2). We compute three-point string scattering amplitudes of massless and slightly massive states, and extract the corresponding effective low energy gauge field theory. The enhanced gauge symmetry at the self-dual point and the Higgs-like mechanism arising when changing the compactification radius are examined in detail. The extra massless fields associated to the enhancement are incorporated into a generalized frame with ((O(d+3,d+3))/(O(d+3)×O(d+3))) structure, where d is the number of non-compact dimensions. We devise a consistent double field theory action that reproduces the low energy string effective action with enhanced gauge symmetry. The construction requires a truly non-geometric frame which explicitly depends on both the compact coordinate along the circle and its dual.

  12. Polarization-dependent optics using gauge-field metamaterials

    International Nuclear Information System (INIS)

    Liu, Fu; Xiao, Shiyi; Li, Jensen; Wang, Saisai; Hang, Zhi Hong

    2015-01-01

    We show that effective gauge field for photons with polarization-split dispersion surfaces, being realized using uniaxial metamaterials, can be used for polarization control with unique opportunities. The metamaterials with the proposed gauge field correspond to a special choice of eigenpolarizations on the Poincaré sphere as pseudo-spins, in contrary to those from either conventional birefringent crystals or optical active media. It gives rise to all-angle polarization control and a generic route to manipulate photon trajectories or polarizations in the pseudo-spin domain. As demonstrations, we show beam splitting (birefringent polarizer), all-angle polarization control, unidirectional polarization filter, and interferometer as various polarization control devices in the pseudo-spin domain. We expect that more polarization-dependent devices can be designed under the same framework

  13. Symmetry breaking by Wilson loops in gauge field theory

    International Nuclear Information System (INIS)

    Dowker, J.S.; Jadhav, S.P.

    1989-01-01

    An analysis is presented of the gauge symmetry breaking caused by Wilson loops on a space-time whose spatial section is openR/sup d/ x S 3 /Γ, for all those fundamental groups Γ that give a homogeneous space. We concentrate on pure SU(3) and SU(5) gauge field theories and find that symmetry breaking can occur when d = 0, for all Γ. If d = 3, the extra minimal scalars prevent any breaking and one must include other fields to achieve this. Explicit forms for the vacuum energies are exhibited in the case of lens and prism spaces, the former for SU(n). For Γ = Z/sub m/, when m and the radius of the sphere become infinite, we recover the results on the space-time openR/sup d//sup +3/ x S 1

  14. Light cone sum rules in nonabelian gauge field theory

    Energy Technology Data Exchange (ETDEWEB)

    Mallik, S [Bern Univ. (Switzerland). Inst. fuer Theoretische Physik

    1981-03-24

    The author examines, in the context of nonabelian gauge field theory, the derivation of the light cone sum rules which were obtained earlier on the assumption of dominance of canonical singularity in the current commutator on the light cone. The retarded scaling functions appearing in the sum rules are numbers known in terms of the charges of the quarks and the number of quarks and gluons in the theory. Possible applications of the sum rules are suggested.

  15. Gauge field geometry from complex and harmonic analyticities

    International Nuclear Information System (INIS)

    Gal'perin, A.S.; Ivanov, E.A.; Ogievetsky, V.I.; Sokatchev, E.

    1987-01-01

    The analyticity preservation principle is employed to demonstrate and impressive affinity between field theories with intrinsic analytic structure and superfield gauge theories. The defining constraints of the former theories are interpreted as the integrability conditions for the existence of appropriate analytic subspaces and are solved by passing to the basis with manifest analyticity. We prefer to work within the analytic basis. This allows, e.g., to replace the nonlinear splitting problem of twistor approach by solving a linear equation

  16. The Weyl non-Abelian gauge field and the Thomas precession

    International Nuclear Information System (INIS)

    Barbashov, B.M.; Pestov, A.B.

    1998-01-01

    The connection between the Fermi-Walker transport and the Weyl non-Abelian gauge field is established. A theoretical possibility of detecting the Weyl gauge field caused by the Thomas precession of a gyroscope is discussed

  17. Frames, the Loewner order and eigendecomposition for morphological operators on tensor fields

    NARCIS (Netherlands)

    van de Gronde, Jasper; Roerdink, Jos B. T. M.

    2014-01-01

    Rotation invariance is an important property for operators on tensor fields, but up to now, most methods for morphology on tensor fields had to either sacrifice rotation invariance, or do without the foundation of mathematical morphology: a lattice structure. Recently, we proposed a framework for

  18. Retrodictive determinism. [covariant and transformational behavior of tensor fields in hydrodynamics and thermodynamics

    Science.gov (United States)

    Kiehn, R. M.

    1976-01-01

    With respect to irreversible, non-homeomorphic maps, contravariant and covariant tensor fields have distinctly natural covariance and transformational behavior. For thermodynamic processes which are non-adiabatic, the fact that the process cannot be represented by a homeomorphic map emphasizes the logical arrow of time, an idea which encompasses a principle of retrodictive determinism for covariant tensor fields.

  19. a tensor theory of gravitation in a curved metric on a flat background

    International Nuclear Information System (INIS)

    Drummond, J.E.

    1979-01-01

    A theory of gravity is proposed using a tensor potential for the field on a flat metric. This potential cannot be isolated by local observations, but some details can be deduced from measurements at a distance. The requirement that the field equations for the tensor potential shall be deducible from an action integral, that the action and field equations are gauge invariant, and, conversely, that the Lagrangian in the action integral can be integrated from the field equations leads to Einstein's field equations. The requirement that the field energy-momentum tensor exists leads to a constraint on the tensor potential. If the constraint is a differential gauge condition, then it can only be the Hilbert condition giving a unique background tensor, metric tensor and tensor potential. For a continuous field inside a solid sphere the metric must be homogeneous in the spatial coordinates, and the associated field energy-momentum tensor has properties consistent with Newtonian dynamics. (author)

  20. Representations of l-p-i functionals in gauge field theories

    International Nuclear Information System (INIS)

    Bordag, M.; Kaschluhn, L.; Matveev, V.A.; Robaschik, D.

    1981-01-01

    A representation of the functions which solve by construction the Slavnov-Taylor identities and contain independent coefficient functions is given. These solutions show the different role of the gauge field which acts in some respect as an ordinary field. The Slavnov-Taylor identities are solved for axial gauge conditions in non-Abelian gauge field theory and in quantum electrodynamics

  1. Modulation of the waterfall by a gauge field

    International Nuclear Information System (INIS)

    Lyth, David H.; Karčiauskas, Mindaugas

    2013-01-01

    We present the first complete calculation of the curvature perturbation generated during the hybrid inflation waterfall, caused by the coupling of the waterfall field to a gauge field A whose kinetic function f 2 depends on the inflaton field. We impose an upper bound on the field A≡fA which ensures that it has a negligible effect before the waterfall. We confirm the claim of Soda and Yokoyama, that the perturbation δB generates a statistically anisotropic spectrum and bispectrum, which could easily be observable. We also discover a new phenomenon, whereby the time-dependent 'varyon' field B causes the inflaton contribution to vary during the waterfall. The varyon mechanism might be implemented also with a scalar field and might not involve the waterfall

  2. 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

  3. On the energy-momentum tensors for field theories in spaces with affine connection and metric

    International Nuclear Information System (INIS)

    Manoff, S.

    1991-01-01

    Generalized covariant Bianchi type identities are obtained and investigated for Lagrangian densities, depending on co- and contravariant tensor fields and their first and second covariant derivatives in spaces with affine connection and metric (L n -space). The notions of canonical, generalized canonical, symmetric and variational energy-momentum tensor are introduced and necessary and sufficient conditions for the existence of the symmetric energy-momentum tensor as a local conserved quantity are obtained. 19 refs.; 1 tab

  4. 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.

  5. Extended BRST symmetries in the gauge field theory

    International Nuclear Information System (INIS)

    Babalean, Aurel; Constantinescu, Radu; Ionescu, Carmen

    2001-01-01

    The BRST procedure provides one of the most powerful methods for the quantum description of the gauge field theories. As already stated, the unphysical degrees of freedom that appear in this case can be easily canceled by the introduction of the ghost type variables. In the Hamiltonian formalism, the structure of the ghost that must be used mainly depends on two factors: - the type of the theory, that this the relations among the constraints of the theory; - the extension of the symmetry to be implemented. The paper presents the structure of the extended phase space suitable for the BRST canonical quantization of a 1- reducible gauge theory in the frame of a BRST symmetry of order three. The corresponding BRST charges and the extended Hamiltonian are also constructed. (authors)

  6. Group quantization on configuration space: Gauge symmetries and linear fields

    International Nuclear Information System (INIS)

    Navarro, M.; Aldaya, V.; Calixto, M.

    1997-01-01

    A new, configuration-space picture of a formalism of group quantization, the GAQ formalism, is presented in the context of a previous algebraic generalization. This presentation serves to make a comprehensive discussion in which other extensions of the formalism, principally to incorporate gauge symmetries, are developed as well. Both images are combined in order to analyze, in a systematic manner and with complete generality, the case of linear fields (Abelian current groups). To illustrate these developments we particularize them for several fields and, in particular, we carry out the quantization of the Abelian Chern endash Simons models over an arbitrary closed surface in detail. copyright 1997 American Institute of Physics

  7. 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

  8. New results in topological field theory and Abelian gauge theory

    Energy Technology Data Exchange (ETDEWEB)

    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.

  9. A recipe for constructing frustration-free Hamiltonians with gauge and matter fields in one and two dimensions

    Science.gov (United States)

    Bernabé Ferreira, Miguel Jorge; Ibieta Jimenez, Juan Pablo; Padmanabhan, Pramod; Teôtonio Sobrinho, Paulo

    2015-12-01

    State sum constructions, such as Kuperberg’s algorithm, give partition functions of physical systems, like lattice gauge theories, in various dimensions by associating local tensors or weights with different parts of a closed triangulated manifold. Here we extend this construction by including matter fields to build partition functions in both two and three space-time dimensions. The matter fields introduce new weights to the vertices and they correspond to Potts spin configurations described by an {A}-module with an inner product. Performing this construction on a triangulated manifold with a boundary we obtain transfer matrices which are decomposed into a product of local operators acting on vertices, links and plaquettes. The vertex and plaquette operators are similar to the ones appearing in the quantum double models (QDMs) of Kitaev. The link operator couples the gauge and the matter fields, and it reduces to the usual interaction terms in known models such as {{{Z}}}2 gauge theory with matter fields. The transfer matrices lead to Hamiltonians that are frustration-free and are exactly solvable. According to the choice of the initial input, that of the gauge group and a matter module, we obtain interesting models which have a new kind of ground state degeneracy that depends on the number of equivalence classes in the matter module under gauge action. Some of the models have confined flux excitations in the bulk which become deconfined at the surface. These edge modes are protected by an energy gap provided by the link operator. These properties also appear in ‘confined Walker-Wang’ models which are 3D models having interesting surface states. Apart from the gauge excitations there are also excitations in the matter sector which are immobile and can be thought of as defects like in the Ising model. We only consider bosonic matter fields in this paper.

  10. Anti-symmetric rank-two tensor matter field on superspace for NT=2

    International Nuclear Information System (INIS)

    Spalenza, Wesley; Ney, Wander G.; Helayel-Neto, J.A.

    2004-01-01

    In this work, we discuss the interaction between anti-symmetric rank-two tensor matter and topological Yang-Mills fields. The matter field considered here is the rank-2 Avdeev-Chizhov tensor matter field in a suitably extended N T =2 SUSY. We start off from the N T =2, D=4 superspace formulation and we go over to Riemannian manifolds. The matter field is coupled to the topological Yang-Mills field. We show that both actions are obtained as Q-exact forms, which allows us to express the energy-momentum tensor as Q-exact observables

  11. Migration transformation of two-dimensional magnetic vector and tensor fields

    DEFF Research Database (Denmark)

    Zhdanov, Michael; Cai, Hongzhu; Wilson, Glenn

    2012-01-01

    We introduce a new method of rapid interpretation of magnetic vector and tensor field data, based on ideas of potential field migration which extends the general principles of seismic and electromagnetic migration to potential fields. 2-D potential field migration represents a direct integral...... to the downward continuation of a well-behaved analytical function. We present case studies for imaging of SQUID-based magnetic tensor data acquired over a magnetite skarn at Tallawang, Australia. The results obtained from magnetic tensor field migration agree very well with both Euler deconvolution and the known...

  12. Gauged N=8 d=5 supergravity

    International Nuclear Information System (INIS)

    Pernici, M.; Pilch, K.; Van Nieuwenhuizen, P.

    1985-01-01

    The complete gauged nonlinear N=8 d=5 supergravity action and supersymmetry transformation laws (without four- and three-fermion terms) are presented. They are obtained from the ungauged model by reinterpreting part of the field strengths of the abelian vector fields as real self-dual second-rank antisymmetric tensors. The complete set of T-tensor indentities are given and their validity is checked numerically. The model has a local Yang-Mills SO(6) and a local composite USp(8) symmetry. The self-duality is essential for the consistent coupling of the antisymmetric tensors to the nonabelian gauge fields. (orig.)

  13. Perturbative formulation of pure space-like axial gauge QED with infrared divergences regularized by residual gauge fields

    International Nuclear Information System (INIS)

    Nakawaki, Yuji; McCartor, Gary

    2006-01-01

    We construct a new perturbative formulation of pure space-like axial gauge QED in which the inherent infrared divergences are regularized by residual gauge fields. For this purpose, we carry out our calculations in the coordinates x μ =(x + , x - , x 1 , x 2 ), where x + =x 0 sinθ + x 3 cosθ and x - = x 0 cosθ - x 3 sinθ. Here, A=A 0 cosθ + A 3 sinθ = n·A=0 is taken as the gauge fixing condition. We show in detail that, in perturbation theory, infrared divergences resulting from the residual gauge fields cancel infrared divergences resulting from the physical parts of the gauge field. As a result, we obtain the gauge field propagator proposed by Mandelstam and Leibbrandt. By taking the limit θ→π/4, we are able to construct a light-cone formulation that is free from infrared divergences. With that analysis complete, we next calculate the one-loop electron self-energy, something not previously done in the light-cone quantization and light-cone gauge. (author)

  14. Questions of quark confinement and ambiguities in Coulomb gauge of Yang-Mills fields

    International Nuclear Information System (INIS)

    Abarbanel, H.D.I.; Bartels, J.

    1978-01-01

    The ambiguities considered by Gribov in the formulation of Coulomb gauge in non-Abelian gauge theories are discussed and the division of gauge field space into a sector with a unique transverse gauge, a sector with a two-fold ambiguity in transverse gauge, etc. is reviewed. The authors argue in a semi-classical fashion that transitions between these sectors readily occur and discuss the connection with ideas of quark confinement in Coulomb gauge. Because of these transitions it appears that the functional integral formulation of Coulomb gauge will be rather more complicated than expected in the past. (Auth.)

  15. Noncommutative gauge theories and Kontsevich's formality theorem

    International Nuclear Information System (INIS)

    Jurco, B.; Schupp, P.; Wess, J.

    2001-01-01

    The equivalence of star products that arise from the background field with and without fluctuations and Kontsevich's formality theorem allow an explicitly construction of a map that relates ordinary gauge theory and noncommutative gauge theory (Seiberg-Witten map.) Using noncommutative extra dimensions the construction is extended to noncommutative nonabelian gauge theory for arbitrary gauge groups; as a byproduct we obtain a 'Mini Seiberg-Witten map' that explicitly relates ordinary abelian and nonabelian gauge fields. All constructions are also valid for non-constant B-field, and even more generally for any Poisson tensor

  16. Gravitational waves in bouncing cosmologies from gauge field production

    Energy Technology Data Exchange (ETDEWEB)

    Ben-Dayan, Ido, E-mail: ido.bendayan@gmail.com [Department of Physics, Ben-Gurion University of the Negev, P.O. Box 653, Be' er-Sheva 8410500 (Israel)

    2016-09-01

    We calculate the gravitational waves (GW) spectrum produced in various Early Universe scenarios from gauge field sources, thus generalizing earlier inflationary calculations to bouncing cosmologies. We consider generic couplings between the gauge fields and the scalar field dominating the energy density of the Universe. We analyze the requirements needed to avoid a backreaction that will spoil the background evolution. When the scalar is coupled only to F F-tilde term, the sourced GW spectrum is exponentially enhanced and parametrically the square of the vacuum fluctuations spectrum, P {sup s} {sub T} ∼ (P {sup v} {sub T} ){sup 2}, giving an even bluer spectrum than the standard vacuum one. When the scalar field is also coupled to F {sup 2} term, the amplitude is still exponentially enhanced, but the spectrum can be arbitrarily close to scale invariant (still slightly blue), n {sub T} ∼> 0, that is distinguishable form the slightly red inflationary one. Hence, we have a proof of concept of observable GW on CMB scales in a bouncing cosmology.

  17. The Scalar, Vector and Tensor Fields in Theory of Elasticity and Plasticity

    Directory of Open Access Journals (Sweden)

    František FOJTÍK

    2014-06-01

    Full Text Available This article is devoted to an analysis of scalar, vector and tensor fields, which occur in the loaded and deformed bodies. The aim of this article is to clarify and simplify the creation of an understandable idea of some elementary concepts and quantities in field theories, such as, for example equiscalar levels, scalar field gradient, Hamilton operator, divergence, rotation and gradient of vector or tensor and others. Applications of those mathematical terms are shown in simple elasticity and plasticity tasks. We hope that content of our article might help technicians to make their studies of necessary mathematical chapters of vector and tensor analysis and field theories easier.

  18. The Simon and Simon-Mars tensors for stationary Einstein-Maxwell fields

    International Nuclear Information System (INIS)

    Bini, Donato; Cherubini, Christian; Jantzen, Robert T; Miniutti, Giovanni

    2004-01-01

    Modulo conventional scale factors, the Simon and Simon-Mars tensors are defined for stationary vacuum spacetimes so that their equality follows from the Bianchi identities of the second kind. In the nonvacuum case one can absorb additional source terms into a redefinition of the Simon tensor so that this equality is maintained. Among the electrovacuum class of solutions of the Einstein-Maxwell equations, the expression for the Simon tensor in the Kerr-Newman-Taub-NUT spacetime in terms of the Ernst potential is formally the same as in the vacuum case (modulo a scale factor), and its vanishing guarantees the simultaneous alignment of the principal null directions of the Weyl tensor, the Papapetrou field associated with the timelike Killing vector field, the electromagnetic field of the spacetime and even the Killing-Yano tensor

  19. Energy-momentum tensor of the gravitational field for material spheres

    International Nuclear Information System (INIS)

    Sokolov, S.N.

    1990-01-01

    Density of the energy-momentum tensor of a gravitational field which can be defined in the general relativity theory with the help of ideas of the relativistic gravitational theory is found for the case of material spheres. A relationship of this quantity with the Riemann tensor R αβγδ is discussed

  20. Group field theory and tensor networks: towards a Ryu–Takayanagi formula in full quantum gravity

    Science.gov (United States)

    Chirco, Goffredo; Oriti, Daniele; Zhang, Mingyi

    2018-06-01

    We establish a dictionary between group field theory (thus, spin networks and random tensors) states and generalized random tensor networks. Then, we use this dictionary to compute the Rényi entropy of such states and recover the Ryu–Takayanagi formula, in two different cases corresponding to two different truncations/approximations, suggested by the established correspondence.

  1. Response of SU(2) lattice gauge theory to a gauge invariant external field

    International Nuclear Information System (INIS)

    Goepfert, M.

    1980-10-01

    Topologically determined Z(2) variables in pure SU(2) lattice gauge theory are discussed. They count the number of 'vortex souls'. The expectation value of the corresponding Z(2) loop and the dependence of the string tension on an external field h coupled to them is calculated to lowest order in the high temperature expansion. The result is in agreement with the conjecture that the probability distribution of vortex souls determines the string tension. A different formula for the string tension is found in the two limiting cases 0 < /h/ << β << 1 and 0 < β << h << 1. This penomenon is traced to the effect of short range interactions of the vortex souls which are mediated by the other excitations in the theory. (orig.)

  2. A multiscale view of propagators in gauge fields

    Energy Technology Data Exchange (ETDEWEB)

    Baeker, M

    1995-07-01

    The Iteratively Smoothing Unigrid (ISU) is presented and studied in detail. An appropriate definition of smoothness in the presence of disordered gauge fields is given on which the algorith is based. ISU uses an iterative process to determ is based. ISU uses an iterative process to determine the interpolation operators as the eigenvectors to the lowest eigenvalues on blocks of larger and larger sizes. We always used the algorith in two dim in two dimensions, usually with SU(2) gauge fields. The ISU algorith perform performs extreely well for the case of the covariant Laplace equation with arbitrarily large disorder. For the Dirac equation, critical slowing down is elimely well for the case of the covariant Laplace equation with arbitrarily large disorder. For the Dirac equation, critical slowing down is eliminated in the continuu lim limit, but when {beta} is kept fixed and the lattice size is increased the critical exponent is estiated to z{approx}1.6. (orig.) methods prove that the problem is due to the many eigenmodes of the Dirac operator that have low eigenvalues and can not be approximated well by the used localized interpolation operators. That the Laplace equation is solved efficiently is caused by the phenomenon of Localization: The lowest modes of the Laplace operator are strongly localized when the disorder of the gauge field is large. We also present an explanation of this phenomenon. For the Dirac operator in two dimension, no localization is found; the reasons for this are not known. It is explained in detail why localization helps to improve the convergence of the algorithm. After having analyzed the problems of the algorithm for the Dirac equation, we try to invent a cure. It consists of two parts: We change the shapes of the supports of the interpolation operators and we introduce the possibility of having more than one interpolation operators per block-lattice point. (Abstract Truncated)

  3. Role of gauge invariance in a variational and mean-field calculation

    International Nuclear Information System (INIS)

    Masperi, L.; Omero, C.

    1981-08-01

    We show that the implementation of gauge invariance is essential for a variational treatment to correctly reproduce all the features of the phase diagram for the Z(2) lattice gauge theory with matter field. (author)

  4. 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.)

  5. Effective Einsteinian gravity from Poincare gauge field theory

    International Nuclear Information System (INIS)

    Baekler, P.; Mielke, E.W.

    1985-10-01

    The Poincare gauge theory of gravity should apply in the microphysical domain. Here we investigate its implications for macrophysics. Weakly self double dual Riemann-Cartan curvature is assumed throughout. It is shown that the metrical background is then determined by Einstein's field equations with the Belinfante-Rosenfeld symmetrized energy-momentum current amended by spin squared terms. Moreover, the effective cosmological constant can be reconciled with the empirical data by absorbing the corresponding constant curvature part into the dynamical torsion of recently found exact solutions. Macroscopically this extra torsion remains undetectable. (author)

  6. Tensor categories and the mathematics of rational and logarithmic conformal field theory

    International Nuclear Information System (INIS)

    Huang, Yi-Zhi; Lepowsky, James

    2013-01-01

    We review the construction of braided tensor categories and modular tensor categories from representations of vertex operator algebras, which correspond to chiral algebras in physics. The extensive and general theory underlying this construction also establishes the operator product expansion for intertwining operators, which correspond to chiral vertex operators, and more generally, it establishes the logarithmic operator product expansion for logarithmic intertwining operators. We review the main ideas in the construction of the tensor product bifunctors and the associativity isomorphisms. For rational and logarithmic conformal field theories, we review the precise results that yield braided tensor categories, and in the rational case, modular tensor categories as well. In the case of rational conformal field theory, we also briefly discuss the construction of the modular tensor categories for the Wess–Zumino–Novikov–Witten models and, especially, a recent discovery concerning the proof of the fundamental rigidity property of the modular tensor categories for this important special case. In the case of logarithmic conformal field theory, we mention suitable categories of modules for the triplet W-algebras as an example of the applications of our general construction of the braided tensor category structure. (review)

  7. A generalization of tensor calculus and its application to physics

    International Nuclear Information System (INIS)

    Ashtekar, A.

    1982-01-01

    Penrose's abstract index notation and axiomatic introduction of covariant derivatives in tensor calculus is generalized to fields with internal degrees of freedom. The result provides, in particular, an intrinsic formulation of gauge theories without the use of bundles. (author)

  8. Fibre bundles associated with fields of geometric objects and a structure tensor

    International Nuclear Information System (INIS)

    Konderak, J.

    1987-08-01

    A construction of a k th structure tensor of a field of geometric objects is presented here (k is a non-negative integer). For a given field σ we construct a vector bundle H k,2 (σ). The k th structure tensor is defined as a section of H k,2 (σ) generated by the torsion of σ. It is then shown that vanishing of the k th structure tensor is a necessary and sufficient condition for the field to be (k + 1)-flat. (author). 16 refs

  9. Body fixed frame, rigid gauge rotations and large N random fields in QCD

    International Nuclear Information System (INIS)

    Levit, S.

    1995-01-01

    The ''body fixed frame'' with respect to local gauge transformations is introduced. Rigid gauge ''rotations'' in QCD and their Schroedinger equation are studied for static and dynamic quarks. Possible choices of the rigid gauge field configuration corresponding to a non-vanishing static colormagnetic field in the ''body fixed'' frame are discussed. A gauge invariant variational equation is derived in this frame. For large number N of colors the rigid gauge field configuration is regarded as random with maximally random probability distribution under constraints on macroscopic-like quantities. For the uniform magnetic field the joint probability distribution of the field components is determined by maximizing the appropriate entropy under the area law constraint for the Wilson loop. In the quark sector the gauge invariance requires the rigid gauge field configuration to appear not only as a background but also as inducing an instantaneous quark-quark interaction. Both are random in the large N limit. (orig.)

  10. Mean fields and self consistent normal ordering of lattice spin and gauge field theories

    International Nuclear Information System (INIS)

    Ruehl, W.

    1986-01-01

    Classical Heisenberg spin models on lattices possess mean field theories that are well defined real field theories on finite lattices. These mean field theories can be self consistently normal ordered. This leads to a considerable improvement over standard mean field theory. This concept is carried over to lattice gauge theories. We construct first an appropriate real mean field theory. The equations determining the Gaussian kernel necessary for self-consistent normal ordering of this mean field theory are derived. (orig.)

  11. From topological quantum field theories to supersymmetric gauge theories

    International Nuclear Information System (INIS)

    Bossard, G.

    2007-10-01

    This thesis contains 2 parts based on scientific contributions that have led to 2 series of publications. The first one concerns the introduction of vector symmetry in cohomological theories, through a generalization of the so-called Baulieu-Singer equation. Together with the topological BRST (Becchi-Rouet-Stora-Tyutin) operator, this symmetry gives an off-shell closed sub-sector of supersymmetry that permits to determine the action uniquely. The second part proposes a methodology for re-normalizing supersymmetric Yang-Mills theory without assuming a regularization scheme which is both supersymmetry and gauge invariance preserving. The renormalization prescription is derived thanks to the definition of 2 consistent Slavnov-Taylor operators for supersymmetry and gauge invariance, whose construction requires the introduction of the so-called shadow fields. We demonstrate the renormalizability of supersymmetric Yang-Mills theories. We give a fully consistent, regularization scheme independent, proof of the vanishing of the β function and of the anomalous dimensions of the one half BPS operators in maximally supersymmetric Yang-Mills theory. After a short introduction, in chapter two, we give a review of the cohomological Yang-Mills theory in eight dimensions. We then study its dimensional reductions in seven and six dimensions. The last chapter gives quite independent results, about a geometrical interpretation of the shadow fields, an unpublished work about topological gravity in four dimensions, an extension of the shadow formalism to superconformal invariance, and finally the solution of the constraints in a twisted superspace. (author)

  12. Massive Higher Dimensional Gauge Fields as Messengers of Supersymmetry Breaking

    International Nuclear Information System (INIS)

    Chacko, Z.; Luty, Markus A.; Ponton, Eduardo

    2000-01-01

    We consider theories with one or more compact dimensions with size r > 1/M, where M is the fundamental Planck scale, with the visible and hidden sectors localized on spatially separated 3 -branes''. We show that a bulk U(1) gauge field spontaneously broken on the hidden-sector 3-brane is an attractive candidate for the messenger of supersymmetry breaking. In this scenario scalar mass-squared terms are proportional to U(1) charges, and therefore naturally conserve flavor. Arbitrary flavor violation at the Planck scale gives rise to exponentially suppressed flavor violation at low energies. Gaugino masses can be generated if the standard gauge fields propagate in the bulk; μ and Bμ terms can be generated by the Giudice-Masiero or by the VEV of a singlet in the visible sector. The latter case naturally solves the SUSY CP problem. Realistic phenomenology can be obtained either if all microscopic parameters are order one in units of M, or if the theory is strongly coupled at the scale M. (For the latter case, we estimate parameters by extending n aive dimensional analysis'' to higher-dimension theories with branes.) In either case, the only unexplained hierarchy is the l arge'' size of the extra dimensions in fundamental units, which need only be an order of magnitude. All soft masses are naturally within an order of magnitude of m 3/2 , and trilinear scalar couplings are negligible. Squark and slepton masses can naturally unify even in the absence of grand unification. (author)

  13. On the large N limit, Wilson Loops, Confinement and Composite Antisymmetric Tensor Field theories

    CERN Document Server

    Castro, C

    2004-01-01

    A novel approach to evaluate the Wilson loops asociated with a $ SU ( \\infty )$ gauge theory in terms of pure string degrees of freedom is presented. It is based on the Guendelman-Nissimov-Pacheva formulation of composite antisymmetric tensor field theories of area (volume ) preserving diffeomorphisms which admit $p$-brane solutions and which provide a $new$ route to scale symmetry breaking and confinement in Yang-Mills theory. The quantum effects are discussed and we evaluate the vacuum expectation values (vev) of the Wilson loops in the large $N$ limit of the $quenched$ reduced $SU(N)$ Yang-Mills theory in terms of a path integral involving pure string degrees of freedom. The $quenched$ approximation is necessary to avoid a crumpling of the string world-sheet giving rise to very large Hausdorff dimensions as pointed out by Olesen. The approach is also consistent with the recent results based on the AdS/CFT correspondence and dual QCD models (dual Higgs model with dual Dirac strings ). More general Loop wav...

  14. 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

  15. Elastic gauge fields and Hall viscosity of Dirac magnons

    Science.gov (United States)

    Ferreiros, Yago; Vozmediano, María A. H.

    2018-02-01

    We analyze the coupling of elastic lattice deformations to the magnon degrees of freedom of magnon Dirac materials. For a honeycomb ferromagnet we find that, as happens in the case of graphene, elastic gauge fields appear coupled to the magnon pseudospinors. For deformations that induce constant pseudomagnetic fields, the spectrum around the Dirac nodes splits into pseudo-Landau levels. We show that when a Dzyaloshinskii-Moriya interaction is considered, a topological gap opens in the system and a Chern-Simons effective action for the elastic degrees of freedom is generated. Such a term encodes a phonon Hall viscosity response, entirely generated by quantum fluctuations of magnons living in the vicinity of the Dirac points. The magnon Hall viscosity vanishes at zero temperature, and grows as temperature is raised and the states around the Dirac points are increasingly populated.

  16. Calibration and characterization of Bayard-Alpert gauges operating in high magnetic fields

    International Nuclear Information System (INIS)

    Pickles, W.L.; Hunt, A.L.

    1985-11-01

    Standard Bayard-Alpert gauges have been successfully operated for several months in the 0.3 to 0.7 T magnetic fields near the plasma edge of the Tandem Mirror Experiment-Upgrade (TMX-U). The gauges clearly measure gas pressure and maintain calibration within 10% during operation. The gauge filaments are tungsten and are heated with DC. The gauge housing allows operation in the low density plasma outside the limiter radius by thermalizing the neutral gas that enters the gauge and by preventing plasma from entering the gauge. Changing the orientation of the gauge with respect to the magnetic field changes the gauge calibration, or effective sensitivity, by as much as a factor of 100. Only some orientations of the filament collector plane with respect to the magnetic field direction allow calibrated operation as a pressure gauge. This range of angles is approximately from 20 to 50 degrees. The gauge is oriented to produce the desired sensitivity, then calibrated for the magnetic field effects for that position. The correction to sensitivity for magnet field is not strongly species dependent. The gauge species sensitivities for CH 4 , Xe,and Kr measured in the high magnetic fields were found to be close to the published values measured in no magnetic field

  17. Magnetic Monopoles, Center Vortices and Topology of Gauge Fields

    OpenAIRE

    Reinhardt, H.; Engelhardt, M.; Langfeld, K.; Quandt, M.; Schafke, A.

    1999-01-01

    The topological properties of magnetic monopoles and center vortices arising, respectively, in Abelian and center gauges are studied in continuum Yang-Mills Theory. For this purpose the continuum analog of the maximum center gauge is constructed.

  18. Magnetic monopoles, center vortices and topology of gauge fields

    International Nuclear Information System (INIS)

    Reinhardt, H.; Engelhardt, M.; Langfeld, K.; Quandt, M.; Schaefke, A.

    2000-01-01

    The topological properties of magnetic monopoles and center vortices arising, respectively, in Abelian and center gauges are studied in continuum Yang-Mills Theory. For this purpose the continuum analog of the maximum center gauge is constructed

  19. Covariant field equations, gauge fields and conservation laws from Yang-Mills matrix models

    International Nuclear Information System (INIS)

    Steinacker, Harold

    2009-01-01

    The effective geometry and the gravitational coupling of nonabelian gauge and scalar fields on generic NC branes in Yang-Mills matrix models is determined. Covariant field equations are derived from the basic matrix equations of motions, known as Yang-Mills algebra. Remarkably, the equations of motion for the Poisson structure and for the nonabelian gauge fields follow from a matrix Noether theorem, and are therefore protected from quantum corrections. This provides a transparent derivation and generalization of the effective action governing the SU(n) gauge fields obtained in [1], including the would-be topological term. In particular, the IKKT matrix model is capable of describing 4-dimensional NC space-times with a general effective metric. Metric deformations of flat Moyal-Weyl space are briefly discussed.

  20. Gauge boson mass without a Higgs field: a simple model

    International Nuclear Information System (INIS)

    Nicholson, A.F.; Kennedy, D.C.

    1997-02-01

    A simple, anomaly-free chiral gauge theory can be perturbatively quantized and renormalized in such a way as to generate fermion and gauge boson masses. This development exploits certain freedoms inherent in choosing the unperturbed Lagrangian and in the renormalization procedure. Apart from its intrinsic interest, such a mechanism might be employed in electroweak gauge theory to generate fermion and gauge boson masses without a Higgs sector. 38 refs

  1. Curvature tensors and unified field equations on SEX/sub n/

    International Nuclear Information System (INIS)

    Chung, K.T.; Lee, I.L.

    1988-01-01

    We study the curvature tensors and field equations in the n-dimensional SE manifold SEX/sub n/. We obtain several basic properties of the vectors S/subλ/ and U/sub λ/ and then of the SE curvature tensor and its contractions, such as a generalized Ricci identity, a generalized Bianchi identity, and two variations of the Bianchi identity satisfied by the SE Einstein tensor. Finally, a system of field equations is discussed in SEX/sub n/ an done of its particular solutions is constructed and displayed

  2. Implementability of gauge transformations and quantization of fermions in external fields

    International Nuclear Information System (INIS)

    Grosse, H.; Karner, G.

    1986-01-01

    Quantization of fermions in an external soliton field, leading to a representation of the CAR which is inequivalent to the representation connected to the massive Dirac operator, is studied. We determine classes of gauge and axial gauge transformations which can be unitarily implemented. In the latter case quantization conditions for gauge functions are obtained; integers entering can be interpreted as winding numbers. (Author)

  3. Quantum theory of gauge fields and rigid processes calculation

    International Nuclear Information System (INIS)

    Andreev, I.V.

    1981-01-01

    Elementary statement of the basic data on the nature of quark interactions and their role in the high energy processes is presented in the first part of the paper. The second part of the paper deals with gauge theory (GT) of strong interactions (chromodynamics (CD)) and its application in calculation of rigid processes with quark participation. It is based on the method of functional integration (MFI). A comparatively simple representation of the MFI in the quantum theory and formulation of the perturbation theory for gauge fields are given. A derivation of the rules of diagram technique is presented. Renormalization invariance of the theory and the basic for CD phenomenon of asymptotical freedom are discussed. Theory application in calculation of certain effects at high energies is considered. From the CD view point considered is a parton model on the base of which ''rigid'' stage of evolution of quark and gluon jets produced at high energies can be quantitatively described and some quantitative experimental tests of the CD are suggested [ru

  4. Electron Gas Dynamic Conductivity Tensor on the Nanotube Surface in Magnetic Field

    Directory of Open Access Journals (Sweden)

    A. M. Ermolaev

    2011-01-01

    Full Text Available Kubo formula was derived for the electron gas conductivity tensor on the nanotube surface in longitudinal magnetic field considering spatial and time dispersion. Components of the degenerate and nondegenerate electron gas conductivity tensor were calculated. The study has showed that under high electron density, the conductivity undergoes oscillations of de Haas-van Alphen and Aharonov-Bohm types with the density of electrons and magnetic field changes.

  5. Conservation laws and stress-energy-momentum tensors for systems with background fields

    Energy Technology Data Exchange (ETDEWEB)

    Gratus, Jonathan, E-mail: j.gratus@lancaster.ac.uk [Lancaster University, Lancaster LA1 4YB (United Kingdom); The Cockcroft Institute, Daresbury Laboratory, Warrington WA4 4AD (United Kingdom); Obukhov, Yuri N., E-mail: yo@thp.uni-koeln.de [Institute for Theoretical Physics, University of Cologne, 50923 Koeln (Germany); Tucker, Robin W., E-mail: r.tucker@lancaster.ac.uk [Lancaster University, Lancaster LA1 4YB (United Kingdom); The Cockcroft Institute, Daresbury Laboratory, Warrington WA4 4AD (United Kingdom)

    2012-10-15

    This article attempts to delineate the roles played by non-dynamical background structures and Killing symmetries in the construction of stress-energy-momentum tensors generated from a diffeomorphism invariant action density. An intrinsic coordinate independent approach puts into perspective a number of spurious arguments that have historically lead to the main contenders, viz the Belinfante-Rosenfeld stress-energy-momentum tensor derived from a Noether current and the Einstein-Hilbert stress-energy-momentum tensor derived in the context of Einstein's theory of general relativity. Emphasis is placed on the role played by non-dynamical background (phenomenological) structures that discriminate between properties of these tensors particularly in the context of electrodynamics in media. These tensors are used to construct conservation laws in the presence of Killing Lie-symmetric background fields. - Highlights: Black-Right-Pointing-Pointer The role of background fields in diffeomorphism invariant actions is demonstrated. Black-Right-Pointing-Pointer Interrelations between different stress-energy-momentum tensors are emphasised. Black-Right-Pointing-Pointer The Abraham and Minkowski electromagnetic tensors are discussed in this context. Black-Right-Pointing-Pointer Conservation laws in the presence of nondynamic background fields are formulated. Black-Right-Pointing-Pointer The discussion is facilitated by the development of a new variational calculus.

  6. Radiative corrections in a vector-tensor model

    International Nuclear Information System (INIS)

    Chishtie, F.; Gagne-Portelance, M.; Hanif, T.; Homayouni, S.; McKeon, D.G.C.

    2006-01-01

    In a recently proposed model in which a vector non-Abelian gauge field interacts with an antisymmetric tensor field, it has been shown that the tensor field possesses no physical degrees of freedom. This formal demonstration is tested by computing the one-loop contributions of the tensor field to the self-energy of the vector field. It is shown that despite the large number of Feynman diagrams in which the tensor field contributes, the sum of these diagrams vanishes, confirming that it is not physical. Furthermore, if the tensor field were to couple with a spinor field, it is shown at one-loop order that the spinor self-energy is not renormalizable, and hence this coupling must be excluded. In principle though, this tensor field does couple to the gravitational field

  7. Gauge and matter fields coupled to N=2 supergravity

    International Nuclear Information System (INIS)

    Wit, B. de; Lauwers, P.G.; Philippe, R.; Su, S.-Q.; Proeyen, A. van.

    1983-07-01

    The authors consider the potential of a general matter system of N=2 vector and scalar multiplets coupled to supergravity. For lagrangians that are initially quadratic in the matter fields the potential is proved to be either positive or unbounded from below. The results have been obtained in the framework of a superconformal multiplet calculus, and it has been verified that they can be derived from each of the three off-shell representations. As an example the authors consider SO(6) Yang-Mills theory coupled to scalar multiplets in the 10+10 representation, which, for suitably chosen parameters, leads to the potential of gauged N=8 supergravity. Finally, a discussion of the possibility to set residual nonabelian symmetry groups after breaking of N=8 supersymmetry to N=1 or 2 is presented. (Auth.)

  8. Gauge invariance of a particle in an external magnetic field

    International Nuclear Information System (INIS)

    Ekstein, H.

    1978-12-01

    In the accepted theory of a nonrelativistic particle in an external field, as well as in the Dirac equation, the canonical momentum p plays a strangely elusive role: contrary to the position q, it has no physical interpretation, yet it is a member of the algebra of observables; nor does it have a well-defined meaning as a translation generator. This paper proposes an observation procedure for p which entails a definite choice for the vector potential A: the radiation gauge divergence of A=0. The canonical momentum, so defined operationally, is shown to be the image of the generator of space translations, in the sense of presymmetry, as the position q is the image of the generator of Galilei boosts in nonrelativistic theories

  9. Full spectrum of Lyapunov exponents in gauge field theories

    International Nuclear Information System (INIS)

    Biro, T.S.; Markum, H.; Pullirsch, R.

    2003-01-01

    Full text: Results are presented for the full spectrum of Lyapunov exponents of the compact U(1) gauge system in classical field theory. Instead of the determination of the largest Lyapunov exponent by the rescaling method we now use the monodromy matrix approach. The Lyapunov spectrum L i is expressed in terms of the eigenvalues Λ i of the monodromy matrix M. In the confinement phase the eigenvalues lie on either the real or on the imaginary axes. This is a nice illustration of a strange attractor of a chaotic system. Positive Lyapunov exponents eject the trajectories from oscillating orbits provided by the imaginary eigenvalues. Negative Lyapunov exponents attract the trajectories keeping them confined in the basin. Latest studies concern the time (in)dependence of the monodromy matrix. Further, we show that monopoles are created and annihilated in pairs as a function of real time in access to a fixed average monopole number. (author)

  10. Chiral gauged Wess-Zumino-Witten theories and coset models in conformal field theory

    International Nuclear Information System (INIS)

    Chung, S.; Tye, S.H.

    1993-01-01

    The Wess-Zumino-Witten (WZW) theory has a global symmetry denoted by G L direct-product G R . In the standard gauged WZW theory, vector gauge fields (i.e., with vector gauge couplings) are in the adjoint representation of the subgroup H contained-in G. In this paper, we show that, in the conformal limit in two dimensions, there is a gauged WZW theory where the gauge fields are chiral and belong to the subgroups H L and H R where H L and H R can be different groups. In the special case where H L =H R , the theory is equivalent to vector gauged WZW theory. For general groups H L and H R , an examination of the correlation functions (or more precisely, conformal blocks) shows that the chiral gauged WZW theory is equivalent to (G/H L ) L direct-product(G/H R ) R coset models in conformal field theory

  11. Weyl gravity as a gauge theory

    Science.gov (United States)

    Trujillo, Juan Teancum

    In 1920, Rudolf Bach proposed an action based on the square of the Weyl tensor or CabcdCabcd where the Weyl tensor is an invariant under a scaling of the metric. A variation of the metric leads to the field equation known as the Bach equation. In this dissertation, the same action is analyzed, but as a conformal gauge theory. It is shown that this action is a result of a particular gauging of this group. By treating it as a gauge theory, it is natural to vary all of the gauge fields independently, rather than performing the usual fourth-order metric variation only. We show that solutions of the resulting vacuum field equations are all solutions to the vacuum Einstein equation, up to a conformal factor---a result consistent with local scale freedom. We also show how solutions for the gauge fields imply there is no gravitational self energy.

  12. Estimation of the magnetic field gradient tensor using the Swarm constellation

    DEFF Research Database (Denmark)

    Kotsiaros, Stavros; Finlay, Chris; Olsen, Nils

    2014-01-01

    For the first time, part of the magnetic field gradient tensor is estimated in space by the Swarm mission. We investigate the possibility of a more complete estimation of the gradient tensor exploiting the Swarm constellation. The East-West gradients can be approximated by observations from...... deviations compared to conventional vector observations at almost all latitudes. Analytical and numerical analysis of the spectral properties of the gradient tensor shows that specific combinations of the East-West and North-South gradients have almost identical signal content to the radial gradient...

  13. Precision of neutron scattering and capacitance type soil water content gauges from field calibration

    International Nuclear Information System (INIS)

    Evett, S.R.; Steiner, J.L.

    1995-01-01

    Soil water content gauges based on neutron scattering (NS) have been a valuable tool for soil water investigations for some 40 yr. However, licensing, training, and safety regulations pertaining to the radioactive source in these gauges makes their use expensive and prevents use in some situations such as unattended monitoring. A capacitance probe (CP) gauge has characteristics that would seem to make it an ideal replacement for NS gauges. We determined the relative precision of two brands of NS gauges (three gauges of each) and a brand of CP gauge (four gauges) in a field calibration exercise. Both brands of NS gauges were calibrated vs. volumetric soil water content with coefficients of determination (r2) ranging from 0.97 to 0.99 and root mean squared errors (RMSE) 0.012 m3 m-3 water content. Calibrations for the CP gauges resulted in r2 ranging from 0.68 to 0.71 and RMSE of 0.036 m3 m-3 water content. Average 95% confidence intervals on predictions were three to five times higher for the CP gauges than for the NS gauges, ranging from 0.153 to 0.161 and 0.032 to 0.052 m3 m-3, respectively. Although poorly correlated with soil water content, readings were reproducible among the four CP gauges. The poor correlation for CP gauges may be due to small-scale soil water content variations within the measurement volume of the gauge. The NS gauges provide acceptable precision but the CP gauge has poor precision and is unacceptable for routine soil water content measurements

  14. On infrared problems of effective Lagrangians of massive spin 2 fields coupled to gauge fields

    Energy Technology Data Exchange (ETDEWEB)

    Canfora, Fabrizio, E-mail: canfora@cecs.cl [Centro de Estudios Científicos (CECs), Casilla 1469, Valdivia (Chile); Giacomini, Alex, E-mail: alexgiacomini@uach.cl [Instituto de Ciencias Físicas y Matemáticas, Universidad Austral de Chile, Valdivia (Chile); Zerwekh, Alfonso R., E-mail: alfonso.zerwekh@usm.cl [Departamento de Física and Centro Científico-Tecnológico de Valparaíso, Universidad Técnica Federico Santa María, Casilla 110-V, Valparaíso (Chile)

    2016-12-15

    In this paper we analyze the interactions of massive spin-2 particles charged under both Abelian and non-Abelian group using the Porrati–Rahman Lagrangian. This theory is valid up to an intrinsic cutoff scale. Phenomenologically a theory valid up to a cutoff scale is sensible as all known higher spin particles are non-fundamental and it is shown that indeed this action can be used to estimate some relevant cross section. Such action necessarily includes Stückelberg field and therefore it is necessary to fix the corresponding gauge symmetry. We show that this theory, when the Stückelberg symmetry is gauge-fixed, possesses a non-trivial infrared problem. A gauge fixing ambiguity arises which is akin to the Gribov problem in QCD in the Abelian case as well. In some cases (such as when the space–time is the four-dimensional torus) the vacuum copies can be found analytically. A similar phenomenon also appears in the case of Proca fields. A very interesting feature of these copies is that they arise only for “large enough” gauge potentials. This opens the possibility to avoid the appearance of such gauge fixing ambiguities by using a Gribov–Zwanziger like approach.

  15. Construction of non-Abelian gauge theories on noncommutative spaces

    International Nuclear Information System (INIS)

    Jurco, B.; Schupp, P.; Moeller, L.; Wess, J.; Max-Planck-Inst. fuer Physik, Muenchen; Humboldt-Univ., Berlin; Schraml, S.; Humboldt-Univ., Berlin

    2001-01-01

    We present a formalism to explicitly construct non-Abelian gauge theories on noncommutative spaces (induced via a star product with a constant Poisson tensor) from a consistency relation. This results in an expansion of the gauge parameter, the noncommutative gauge potential and fields in the fundamental representation, in powers of a parameter of the noncommutativity. This allows the explicit construction of actions for these gauge theories. (orig.)

  16. Construction of non-Abelian gauge theories on noncommutative spaces

    Energy Technology Data Exchange (ETDEWEB)

    Jurco, B.; Schupp, P. [Sektion Physik, Muenchen Univ. (Germany); Moeller, L.; Wess, J. [Sektion Physik, Muenchen Univ. (Germany); Max-Planck-Inst. fuer Physik, Muenchen (Germany); Humboldt-Univ., Berlin (Germany). Inst. fuer Physik; Schraml, S. [Sektion Physik, Muenchen Univ. (Germany)

    2001-06-01

    We present a formalism to explicitly construct non-Abelian gauge theories on noncommutative spaces (induced via a star product with a constant Poisson tensor) from a consistency relation. This results in an expansion of the gauge parameter, the noncommutative gauge potential and fields in the fundamental representation, in powers of a parameter of the noncommutativity. This allows the explicit construction of actions for these gauge theories. (orig.)

  17. Current density tensors

    Science.gov (United States)

    Lazzeretti, Paolo

    2018-04-01

    It is shown that nonsymmetric second-rank current density tensors, related to the current densities induced by magnetic fields and nuclear magnetic dipole moments, are fundamental properties of a molecule. Together with magnetizability, nuclear magnetic shielding, and nuclear spin-spin coupling, they completely characterize its response to magnetic perturbations. Gauge invariance, resolution into isotropic, deviatoric, and antisymmetric parts, and contributions of current density tensors to magnetic properties are discussed. The components of the second-rank tensor properties are rationalized via relationships explicitly connecting them to the direction of the induced current density vectors and to the components of the current density tensors. The contribution of the deviatoric part to the average value of magnetizability, nuclear shielding, and nuclear spin-spin coupling, uniquely determined by the antisymmetric part of current density tensors, vanishes identically. The physical meaning of isotropic and anisotropic invariants of current density tensors has been investigated, and the connection between anisotropy magnitude and electron delocalization has been discussed.

  18. Cosmology in Gauge Field Theory and String Theory

    International Nuclear Information System (INIS)

    Garcia Compean, H

    2005-01-01

    This new book is intended for students and researchers who want to go into the interplay between cosmology and high-energy physics. It assumes a prior knowledge of these subjects such as some of the topics contained in the previous books by the authors, Introduction to Gauge Field Theory (1993 Bristol: Institute of Physics Publishing) and Supersymmetric Gauge Field Theory and String Theory (1994 Bristol: Institute of Physics Publishing). However, the book is intended to be self-contained, explaining, from a modern perspective, some background material mainly in standard cosmology, topological defects, baryogenesis, inflationary cosmology and, at the end of the book, some of the basics of string theory. What is distinctively new about this book is that it lies in the interplay between cosmology and high-energy physics typically above 100 GeV (10 15 K). Often these subjects are presented in regular textbooks in a disconnected way, or in research papers, proceedings and review papers but usually not in a pedagogical style. Thus, in this sense, the book is unique and deserves a special place in the recent literature. The book starts by reviewing the standard material of the early universe. The standard model of cosmology from a modern perspective is revised in chapter 1. In chapter 2, phase transitions in different models are discussed, Higgs, electroweak, GUTs, supersymmetric GUTs and supergravity, by using quantum field theory at finite temperature. Chapter 3 is devoted to a general account of topological defects and discusses how they arise as possible remnants of these phase transitions in GUTs. Other relics, such as neutrinos and axions, are introduced in chapter 5 and their impact in cosmology is assessed. In chapter 4, some of the most relevant mechanisms of baryogenesis are discussed in the context of the different GUTs and the minimal supersymmetric standard model (MSSM). Inflation is also discussed in the context of GUTs. In chapter 6, the authors introduce

  19. Light-cone gauge approach to arbitrary spin fields, currents and shadows

    International Nuclear Information System (INIS)

    Metsaev, R R

    2014-01-01

    Totally symmetric arbitrary spin fields in AdS space, conformal fields, conformal currents, and shadow fields in flat space are studied. Light-cone gauge formulations for such fields, currents and shadows are obtained. Use of the Poincaré parametrization of AdS space and ladder operators allows us to treat fields in flat and AdS spaces on an equal footing. Light-cone gauge realization of relativistic symmetries for fields, currents and shadows is also obtained. The light-cone gauge formulation for fields is obtained by using the gauge invariant Lagrangian which is presented in terms of modified de Donder divergence, while the light-cone gauge formulation for currents and shadows is obtained by using the gauge invariant approach to currents and shadows. This allows us to demonstrate explicitly how the ladder operators entering the gauge invariant formulation of fields, currents and shadows manifest themselves in the light-cone gauge formulation for fields, currents and shadows. (paper)

  20. A GENERALIZED DIFFUSION TENSOR FOR FULLY ANISOTROPIC DIFFUSION OF ENERGETIC PARTICLES IN THE HELIOSPHERIC MAGNETIC FIELD

    International Nuclear Information System (INIS)

    Effenberger, F.; Fichtner, H.; Scherer, K.; Barra, S.; Kleimann, J.; Strauss, R. D.

    2012-01-01

    The spatial diffusion of cosmic rays in turbulent magnetic fields can, in the most general case, be fully anisotropic, i.e., one has to distinguish three diffusion axes in a local, field-aligned frame. We reexamine the transformation for the diffusion tensor from this local to a global frame, in which the Parker transport equation for energetic particles is usually formulated and solved. Particularly, we generalize the transformation formulae to allow for an explicit choice of two principal local perpendicular diffusion axes. This generalization includes the 'traditional' diffusion tensor in the special case of isotropic perpendicular diffusion. For the local frame, we describe the motivation for the choice of the Frenet-Serret trihedron, which is related to the intrinsic magnetic field geometry. We directly compare the old and the new tensor elements for two heliospheric magnetic field configurations, namely the hybrid Fisk and Parker fields. Subsequently, we examine the significance of the different formulations for the diffusion tensor in a standard three-dimensional model for the modulation of galactic protons. For this, we utilize a numerical code to evaluate a system of stochastic differential equations equivalent to the Parker transport equation and present the resulting modulated spectra. The computed differential fluxes based on the new tensor formulation deviate from those obtained with the 'traditional' one (only valid for isotropic perpendicular diffusion) by up to 60% for energies below a few hundred MeV depending on heliocentric distance.

  1. Gauged BRST symmetry and the occurence of higher cocycles in quantum field theory

    International Nuclear Information System (INIS)

    Baulieu, L.; Grossman, B.; Stora, R.

    1986-06-01

    The BRST symmetry of Yang Mills theories can be gauged via the introduction of an anticommuting single gauge field. There follows the construction of a local BRST operation which allows an algebraic analysis of the BRST current algebra. This construction provides, in particular, a field theory interpretation of most higher cocycles which accompany the usual chiral anomaly

  2. Ultraviolet stability of three-dimensional lattice pure gauge field theories

    International Nuclear Information System (INIS)

    Balaban, T.

    1985-01-01

    We prove the ultraviolet stability for three-dimensional lattice gauge field theories. We consider only the Wilson lattice approximation for pure Yang-Mills field theories. The proof is based on results of the previous papers on renormalization group method for lattice gauge theories. (orig.)

  3. Possible physical manifestation of the Weyl non-Abelian gauge field

    International Nuclear Information System (INIS)

    Barbashov, B.M.; Pestov, A.B.

    1998-01-01

    On the basis of the Weyl equations of congruent transference, we consider a possible influence of the Weyl non-Abelian gauge field defining the transference on the precession of a gyroscope. Plane-wave solutions to the equations of the Abelian gauge field are derived

  4. Unveiling a spinor field classification with non-Abelian gauge symmetries

    Science.gov (United States)

    Fabbri, Luca; da Rocha, Roldão

    2018-05-01

    A spinor fields classification with non-Abelian gauge symmetries is introduced, generalizing the U(1) gauge symmetries-based Lounesto's classification. Here, a more general classification, contrary to the Lounesto's one, encompasses spinor multiplets, corresponding to non-Abelian gauge fields. The particular case of SU(2) gauge symmetry, encompassing electroweak and electromagnetic conserved charges, is then implemented by a non-Abelian spinor classification, now involving 14 mixed classes of spinor doublets. A richer flagpole, dipole, and flag-dipole structure naturally descends from this general classification. The Lounesto's classification of spinors is shown to arise as a Pauli's singlet, into this more general classification.

  5. Physical principles, geometrical aspects, and locality properties of gauge field theories

    International Nuclear Information System (INIS)

    Mack, G.; Hamburg Univ.

    1981-01-01

    Gauge field theories, particularly Yang - Mills theories, are discussed at a classical level from a geometrical point of view. The introductory chapters are concentrated on physical principles and mathematical tools. The main part is devoted to locality problems in gauge field theories. Examples show that locality problems originate from two sources in pure Yang - Mills theories (without matter fields). One is topological and the other is related to the existence of degenerated field configurations of the infinitesimal holonomy groups on some extended region of space or space-time. Nondegenerate field configurations in theories with semisimple gauge groups can be analysed with the help of the concept of a local gauge. Such gauges play a central role in the discussion. (author)

  6. Gravitational waves from non-Abelian gauge fields at a tachyonic transition

    Science.gov (United States)

    Tranberg, Anders; Tähtinen, Sara; Weir, David J.

    2018-04-01

    We compute the gravitational wave spectrum from a tachyonic preheating transition of a Standard Model-like SU(2)-Higgs system. Tachyonic preheating involves exponentially growing IR modes, at scales as large as the horizon. Such a transition at the electroweak scale could be detectable by LISA, if these non-perturbatively large modes translate into non-linear dynamics sourcing gravitational waves. Through large-scale numerical simulations, we find that the spectrum of gravitational waves does not exhibit such IR features. Instead, we find two peaks corresponding to the Higgs and gauge field mass, respectively. We find that the gravitational wave production is reduced when adding non-Abelian gauge fields to a scalar-only theory, but increases when adding Abelian gauge fields. In particular, gauge fields suppress the gravitational wave spectrum in the IR. A tachyonic transition in the early Universe will therefore not be detectable by LISA, even if it involves non-Abelian gauge fields.

  7. Radiation reaction for the classical relativistic spinning particle in scalar, tensor and linearized gravitational fields

    International Nuclear Information System (INIS)

    Barut, A.O.; Cruz, M.G.

    1992-08-01

    We use the method of analytic continuation of the equation of motion including the self-fields to evaluate the radiation reaction for a classical relativistic spinning point particle in interaction with scalar, tensor and linearized gravitational fields in flat spacetime. In the limit these equations reduce to those of spinless particles. We also show the renormalizability of these theories. (author). 10 refs

  8. Stochastic massless fields I: Integer spin

    International Nuclear Information System (INIS)

    Lim, S.C.

    1981-04-01

    Nelson's stochastic quantization scheme is applied to classical massless tensor potential in ''Coulomb'' gauge. The relationship between stochastic potential field in various gauges is discussed using the case of vector potential as an illustration. It is possible to identify the Euclidean tensor potential with the corresponding stochastic field in physical Minkowski space-time. Stochastic quantization of massless fields can also be carried out in terms of field strength tensors. An example of linearized stochastic gravitational field in vacuum is given. (author)

  9. Gauge-invariant expectation values of the energy of a molecule in an electromagnetic field

    International Nuclear Information System (INIS)

    Mandal, Anirban; Hunt, Katharine L. C.

    2016-01-01

    In this paper, we show that the full Hamiltonian for a molecule in an electromagnetic field can be separated into a molecular Hamiltonian and a field Hamiltonian, both with gauge-invariant expectation values. The expectation value of the molecular Hamiltonian gives physically meaningful results for the energy of a molecule in a time-dependent applied field. In contrast, the usual partitioning of the full Hamiltonian into molecular and field terms introduces an arbitrary gauge-dependent potential into the molecular Hamiltonian and leaves a gauge-dependent form of the Hamiltonian for the field. With the usual partitioning of the Hamiltonian, this same problem of gauge dependence arises even in the absence of an applied field, as we show explicitly by considering a gauge transformation from zero applied field and zero external potentials to zero applied field, but non-zero external vector and scalar potentials. We resolve this problem and also remove the gauge dependence from the Hamiltonian for a molecule in a non-zero applied field and from the field Hamiltonian, by repartitioning the full Hamiltonian. It is possible to remove the gauge dependence because the interaction of the molecular charges with the gauge potential cancels identically with a gauge-dependent term in the usual form of the field Hamiltonian. We treat the electromagnetic field classically and treat the molecule quantum mechanically, but nonrelativistically. Our derivation starts from the Lagrangian for a set of charged particles and an electromagnetic field, with the particle coordinates, the vector potential, the scalar potential, and their time derivatives treated as the variables in the Lagrangian. We construct the full Hamiltonian using a Lagrange multiplier method originally suggested by Dirac, partition this Hamiltonian into a molecular term H m and a field term H f , and show that both H m and H f have gauge-independent expectation values. Any gauge may be chosen for the calculations; but

  10. Magnetic monopoles, center vortices, confinement and topology of gauge fields

    International Nuclear Information System (INIS)

    Reinhardt, H.; Engelhardt, M.; Langfeld, K.; Quandt, M.; Schaefke, A.

    2000-01-01

    The vortex picture of confinement is studied. The deconfinement phase transition is explained as a transition from a phase in which vortices percolate to a phase of small vortices. Lattice results are presented in support of this scenario. Furthermore the topological properties of magnetic monopoles and center vortices arising, respectively, in Abelian and center gauges are studied in continuum Yang-Mills-theory. For this purpose the continuum analog of the maximum center gauge is constructed

  11. Magnetic Monopoles, Center Vortices, Confinement and Topology of Gauge Fields

    OpenAIRE

    Reinhardt, H.; Engelhardt, M.; Langfeld, K.; Quandt, M.; Sch"afke, A.

    1999-01-01

    The vortex picture of confinement is studied. The deconfinement phase transition is explained as a transition from a phase in which vortices percolate to a phase of small vortices. Lattice results are presented in support of this scenario. Furthermore the topological properties of magnetic monopoles and center vortices arising, respectively, in Abelian and center gauges are studied in continuum Yang-Mills-theory. For this purpose the continuum analog of the maximum center gauge is constructed.

  12. 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...

  13. Study of the tensor correlation in oxygen isotopes using mean-field-type and shell model methods

    International Nuclear Information System (INIS)

    Sugimoto, Satoru

    2007-01-01

    The tensor force plays important roles in nuclear structure. Recently, we have developed a mean-field-type model which can treat the two-particle-two-hole correlation induced by the tensor force. We applied the model to sub-closed-shell oxygen isotopes and found that an sizable attractive energy comes from the tensor force. We also studied the tensor correlation in 16O using a shell model including two-particle-two-hole configurations. In this case, quite a large attractive energy is obtained for the correlation energy from the tensor force

  14. Canonical Yang-Mills field theory with invariant gauge-families

    International Nuclear Information System (INIS)

    Yokoyama, Kan-ichi

    1978-01-01

    A canonical Yang-Mills field theory with indefinite metric is presented on the basis of a covariant gauge formalism for quantum electrodynamics. As the first step of the formulation, a many-gauge-field problem, in which many massless Abelian-gauge fields coexist, is treated from a new standpoint. It is shown that only a single pair of a gaugeon field and its associated one can govern the gauge structure of the whole system. The result obtained is further extended to cases of non-Abelian gauge theories. Gauge parameters for respective components of the Yang-Mills fields are introduced as a group vector. There exists a q-number local gauge transformation which connects relevant fields belonging to the same invariant gauge family with one another in a manifestly covariant way. In canonical quantization, the Faddeev-Popov ghosts are introduced in order to guarantee the existence of a desirable physical subspace with positive semi-definite metric. As to treatment of the Faddeev-Popov ghosts, Kugo and Ojima's approach is adopted. Three supplementary conditions which are consistent with one another constrain the physical subspace. (author)

  15. Metal–insulator crossover in high Tc cuprates: A gauge field approach

    Indian Academy of Sciences (India)

    plane resistivity of underdoped cuprates and a range of superconducting cuprates in the presence of a strong magnetic field suppressing superconductivity. We propose an explanation for this phenomenon based on a gauge field theory approach ...

  16. Modified weak energy condition for the energy momentum tensor in quantum field theory

    International Nuclear Information System (INIS)

    Latorre, J.

    1998-01-01

    The weak energy condition is known to fail in general when applied to expectation values of the energy momentum tensor in flat space quantum field theory. It is shown how the usual counter arguments against its validity are no longer applicable if the states vertical stroke ψ right angle for which the expectation value is considered are restricted to a suitably defined subspace. A possible natural restriction on vertical stroke ψ right angle is suggested and illustrated by two quantum mechanical examples based on a simple perturbed harmonic oscillator Hamiltonian. The proposed alternative quantum weak energy condition is applied to states formed by the action of the scalar, vector and the energy momentum tensor operators on the vacuum. We assume conformal invariance in order to determine almost uniquely three-point functions involving the energy momentum tensor in terms of a few parameters. The positivity conditions lead to non-trivial inequalities for these parameters. They are satisfied in free field theories, except in one case for dimensions close to two. Further restrictions on vertical stroke ψ right angle are suggested which remove this problem. The inequalities which follow from considering the state formed by applying the energy momentum tensor to the vacuum are shown to imply that the coefficient of the topological term in the expectation value of the trace of the energy momentum tensor in an arbitrary curved space background is positive, in accord with calculations in free field theories. (orig.)

  17. A continuous tensor field approximation of discrete DT-MRI data for extracting microstructural and architectural features of tissue.

    Science.gov (United States)

    Pajevic, Sinisa; Aldroubi, Akram; Basser, Peter J

    2002-01-01

    The effective diffusion tensor of water, D, measured by diffusion tensor MRI (DT-MRI), is inherently a discrete, noisy, voxel-averaged sample of an underlying macroscopic effective diffusion tensor field, D(x). Within fibrous tissues this field is presumed to be continuous and smooth at a gross anatomical length scale. Here a new, general mathematical framework is proposed that uses measured DT-MRI data to produce a continuous approximation to D(x). One essential finding is that the continuous tensor field representation can be constructed by repeatedly performing one-dimensional B-spline transforms of the DT-MRI data. The fidelity and noise-immunity of this approximation are tested using a set of synthetically generated tensor fields to which background noise is added via Monte Carlo methods. Generally, these tensor field templates are reproduced faithfully except at boundaries where diffusion properties change discontinuously or where the tensor field is not microscopically homogeneous. Away from such regions, the tensor field approximation does not introduce bias in useful DT-MRI parameters, such as Trace(D(x)). It also facilitates the calculation of several new parameters, particularly differential quantities obtained from the tensor of spatial gradients of D(x). As an example, we show that they can identify tissue boundaries across which diffusion properties change rapidly using in vivo human brain data. One important application of this methodology is to improve the reliability and robustness of DT-MRI fiber tractography.

  18. Verification of Equivalence of the Axial Gauge to the Coulomb Gauge in QED by Embedding in the Indefinite Metric Hilbert Space : Particles and Fields

    OpenAIRE

    Yuji, NAKAWAKI; Azuma, TANAKA; Kazuhiko, OZAKI; Division of Physics and Mathematics, Faculty of Engineering Setsunan University; Junior College of Osaka Institute of Technology; Faculty of General Education, Osaka Institute of Technology

    1994-01-01

    Gauge Equivalence of the A_3=0 (axial) gauge to the Coulomb gauge is directly verified in QED. For that purpose a pair of conjugate zero-norm fields are introduced. This enables us to construct a canonical formulation in the axial gauge embedded in the indefinite metric Hilbert space in such a way that the Feynman rules are not altered. In the indefinite metric Hilbert space we can implement a gauge transformation, which otherwise has to be carried out only by hand, as main parts of a canonic...

  19. Lagrangian analysis of vector and tensor fields: Algorithmic foundations and applications in medical imaging and computational fluid dynamics

    OpenAIRE

    Ding, Zi'ang

    2016-01-01

    Both vector and tensor fields are important mathematical tools used to describe the physics of many phenomena in science and engineering. Effective vector and tensor field visualization techniques are therefore needed to interpret and analyze the corresponding data and achieve new insight into the considered problem. This dissertation is concerned with the extraction of important structural properties from vector and tensor datasets. Specifically, we present a unified approach for the charact...

  20. Gauge-field topology in two dimensions: θ-vacuum, topological phases and composite fields

    International Nuclear Information System (INIS)

    Ilieva, N.; Pervushin, V.N.

    1990-06-01

    In the framework of the minimal quantization method, the residual 'longitudinal' vacuum dynamics of the Abelian gauge field, that is described by a new pair of canonical variables, is revealed. This dynamics is shown to give origin to the θ-vacuum, thus providing a field analogy of the Josephson effect. The destructive interference of the topological phases - that the fermion fields are shown to acquire - is considered as a reason for the charge screening in the two-dimensional massless QED. (author). 11 refs

  1. Stochastic quantization and gauge-fixing of the linearized gravitational field

    International Nuclear Information System (INIS)

    Hueffel, H.; Rumpf, H.

    1984-01-01

    Due to the indefiniteness of the Euclidean gravitational action the Parisi-Wu stochastic quantization scheme fails in the case of the gravitational field. Therefore we apply a recently proposed modification of stochastic quantization that works in Minkowski space and preserves all the advantages of the original Parisi-Wu method; in particular no gauge-fixing is required. Additionally stochastic gauge-fixing may be introduced and is also studied in detail. The graviton propagators obtained with and without stochastic gauge-fixing all exhibit a noncausal contribution, but apart from this effect the gauge-invariant quantities are the same as those of standard quantization. (Author)

  2. Towards a coupled-cluster treatment of SU(N) lattice gauge field theory

    NARCIS (Netherlands)

    Bishop, Raymond F.; Ligterink, N.E.; Walet, Niels R.

    2006-01-01

    A consistent approach to Hamiltonian SU(N) lattice gauge field theory is developed using the maximal-tree gauge and an appropriately chosen set of angular variables. The various constraints are carefully discussed, as is a practical means for their implementation. A complete set of variables for the

  3. Noncontractible hyperloops in gauge models with Higgs fields in the fundamental representation

    Science.gov (United States)

    Burzlaff, Jürgen

    1984-11-01

    We study finite-energy configurations in SO( N) gauge theories with Higgs fields in the fundamental representation. For all winding numbers, noncontractible hyperloops are constructed. The corresponding energy density is spherically symmetric, and the configuration with maximal energy on each hyperloop can be determined. Noncontractible hyperloops with an arbitrary winding number for SU(2) gauge theory are also given.

  4. Noncontractible hyperloops in gauge models with Higgs fields in the fundamental representation

    International Nuclear Information System (INIS)

    Burzlaff, J.

    1984-01-01

    We study finite-energy configurations in SO(N) gauge theories with Higgs fields in the fundamental representation. For all winding numbers, noncontractible hyperloops are constructed. The corresponding energy density is spherically symmetric, and the configuration with maximal energy on each hyperloop can be determined. Noncontractible hyperloops with an arbitrary winding number for SU(2) gauge theory are also given. (orig.)

  5. Noncontractible hyperloops in gauge models with Higgs fields in the fundamental representation

    Energy Technology Data Exchange (ETDEWEB)

    Burzlaff, J. (Dublin Inst. for Advanced Studies (Ireland). School of Theoretical Physics)

    1984-11-01

    We study finite-energy configurations in SO(N) gauge theories with Higgs fields in the fundamental representation. For all winding numbers, noncontractible hyperloops are constructed. The corresponding energy density is spherically symmetric, and the configuration with maximal energy on each hyperloop can be determined. Noncontractible hyperloops with an arbitrary winding number for SU(2) gauge theory are also given.

  6. Tensor modes in pure natural inflation

    Science.gov (United States)

    Nomura, Yasunori; Yamazaki, Masahito

    2018-05-01

    We study tensor modes in pure natural inflation [1], a recently-proposed inflationary model in which an axionic inflaton couples to pure Yang-Mills gauge fields. We find that the tensor-to-scalar ratio r is naturally bounded from below. This bound originates from the finiteness of the number of metastable branches of vacua in pure Yang-Mills theories. Details of the model can be probed by future cosmic microwave background experiments and improved lattice gauge theory calculations of the θ-angle dependence of the vacuum energy.

  7. Scale transformation and massless limit in neutral-vector field theory. [Gauge transformation unified theory

    Energy Technology Data Exchange (ETDEWEB)

    Kubo, R; Takahashi, Y; Yokoyama, K

    1975-01-01

    In a wide class of neutral vector field theories, in which massive and massless fields are described in a unified way and a unique massless limit exists to quantum electrodynamics in covariant gauges, the commutability of the scale transformation and the massless limit is examined. It is shown that there occurs no anomaly with respect to the assignment for scale dimensions of relevant fields. Connection of scale transformation and gauge transformation is also discussed.

  8. Balancing anisotropic curvature with gauge fields in a class of shear-free cosmological models

    Science.gov (United States)

    Thorsrud, Mikjel

    2018-05-01

    We present a complete list of general relativistic shear-free solutions in a class of anisotropic, spatially homogeneous and orthogonal cosmological models containing a collection of n independent p-form gauge fields, where p\\in\\{0, 1, 2, 3\\} , in addition to standard ΛCDM matter fields modelled as perfect fluids. Here a (collection of) gauge field(s) balances anisotropic spatial curvature on the right-hand side of the shear propagation equation. The result is a class of solutions dynamically equivalent to standard FLRW cosmologies, with an effective curvature constant Keff that depends both on spatial curvature and the energy density of the gauge field(s). In the case of a single gauge field (n  =  1) we show that the only spacetimes that admit such solutions are the LRS Bianchi type III, Bianchi type VI0 and Kantowski–Sachs metric, which are dynamically equivalent to open (Keff0 ) FLRW models, respectively. With a collection of gauge fields (n  >  1) also Bianchi type II admits a shear-free solution (Keff>0 ). We identify the LRS Bianchi type III solution to be the unique shear-free solution with a gauge field Hamiltonian bounded from below in the entire class of models.

  9. Axial-gauge formulation of a three-dimensional field theory

    International Nuclear Information System (INIS)

    Hagen, C.R.

    1985-01-01

    Since the non-Abelian version of a recently formulated gauge theory in two spatial dimensions gives rise to a nonlinear constraint upon the fields in the radiation-gauge approach, one is motivated to attempt a description in terms of the axial gauge. This is accomplished in the Abelian version of the model, with results similar to those encountered in the radiation gauge. The non-Abelian case is then formally solved in the same gauge, it being subsequently shown, however, that the theory is not covariant. It is argued on the basis of perturbation theory that such noncovariance is a real effect which is not readily circumvented by modification of the field transformation properties

  10. Copula-based assimilation of radar and gauge information to derive bias-corrected precipitation fields

    Directory of Open Access Journals (Sweden)

    S. Vogl

    2012-07-01

    Full Text Available This study addresses the problem of combining radar information and gauge measurements. Gauge measurements are the best available source of absolute rainfall intensity albeit their spatial availability is limited. Precipitation information obtained by radar mimics well the spatial patterns but is biased for their absolute values.

    In this study copula models are used to describe the dependence structure between gauge observations and rainfall derived from radar reflectivity at the corresponding grid cells. After appropriate time series transformation to generate "iid" variates, only the positive pairs (radar >0, gauge >0 of the residuals are considered. As not each grid cell can be assigned to one gauge, the integration of point information, i.e. gauge rainfall intensities, is achieved by considering the structure and the strength of dependence between the radar pixels and all the gauges within the radar image. Two different approaches, namely Maximum Theta and Multiple Theta, are presented. They finally allow for generating precipitation fields that mimic the spatial patterns of the radar fields and correct them for biases in their absolute rainfall intensities. The performance of the approach, which can be seen as a bias-correction for radar fields, is demonstrated for the Bavarian Alps. The bias-corrected rainfall fields are compared to a field of interpolated gauge values (ordinary kriging and are validated with available gauge measurements. The simulated precipitation fields are compared to an operationally corrected radar precipitation field (RADOLAN. The copula-based approach performs similarly well as indicated by different validation measures and successfully corrects for errors in the radar precipitation.

  11. Amount of gauge transformations in neutral-vector field theory. [Renormalization, free Lagrangian density

    Energy Technology Data Exchange (ETDEWEB)

    Kubo, R; Yokoyama, K

    1974-11-01

    The purpose of this work is to study the structure of c-number gauge transformation in connection with renormalization problem. In the wide theory of neutral vector fields, there is the gauge structure described essentially by free Lagrangian density. The c-number gauge transformation makes the Lagrangian invariant correspondingly to the usual case of quantum electrodynamics. The c-number transformation can be used to derive relationships among all relevant renormalization constants in the case of interacting fields. In the presence of interaction, total Lagrangian density L is written as L=L/sub 0/+L/sub 1/+L/sub 2/, where L/sub 1/ is given from matter-field Lagrangian density, and L/sub 2/ denotes necessary additional counter terms. In order to conserve the gauge structure, the form of L is invariant under the gauge transformation. Since L matter is self-adjoining, L/sub 1/ remains invariant by itself under the transformation. The form of L/sub 2/ is finally given from the observation that L/sub 3/ cannot contain wave-function renormalization constants. Since L/sub 2/ is invariant under q-number gauge transformation, this transformation in unrenormalized form makes the present L form-invariant. Therefore, together with the above results, auxiliary fields produce the q-number gauge transformation for renormalized fields.

  12. 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

  13. A short proof that the Coulomb-gauge potentials yield the retarded fields

    Energy Technology Data Exchange (ETDEWEB)

    Heras, Jose A, E-mail: herasgomez@gmail.co [Universidad Autonoma Metropolitana, Unidad Azcapotzalco, Av. San Pablo No. 180, Col. Reynosa, Mexico D. F. 02200 (Mexico)

    2011-01-15

    A short demonstration that the potentials in the Coulomb gauge yield the retarded electric and magnetic fields is presented. This demonstration is relatively simple and can be presented in an advanced undergraduate course of electromagnetic theory.

  14. A short proof that the Coulomb-gauge potentials yield the retarded fields

    International Nuclear Information System (INIS)

    Heras, Jose A

    2011-01-01

    A short demonstration that the potentials in the Coulomb gauge yield the retarded electric and magnetic fields is presented. This demonstration is relatively simple and can be presented in an advanced undergraduate course of electromagnetic theory.

  15. The Investigation of Screening of Chromoelectric and Chromomagnetic Fields in QGP in Noncovariant Gauges

    International Nuclear Information System (INIS)

    Veliev, E.S.

    2004-01-01

    According to Thermal Quantum Chromodynamics (TQCD) hadron matter may be exist in different phase states, in particular, in the form of quark-gluon plasma (QGP). The aim of the present work is to investigate the screening of chromoelectric and chromomagnetic fields in QGP in temporal gauge. In temporal gauge gluon propagator has the unphysical poles. Hence, in the gluon self energy diagram calculations the singularities appear. In order to remove these singularities we used Leibbrandt-Mandelstam prescription. We obtained that chromoelectric fields are screened, but chromomagnetic fields are not screened. In coordinate space, the screening of chromoelectric fields reduces the range of gauge interactions. In momentum space, it contributes to regulate the infrared behavior of the various n-point Green functions. Also, it is shown that the obtained results are gauge invariant

  16. Gauge invariant frequency splitting of the continuum Yang-Mills field

    International Nuclear Information System (INIS)

    Mitter, P.K.; Valent, G.

    1977-01-01

    Frequency splitting plays an important role in Wilson's theory of critical phenomena. Here the authors give a theory of gauge invariant frequency splitting of the Yang-Mills field in 4 dimensions. (Auth.)

  17. The Einsteinian T(3)-gauge approach and the stress tensor of the screw dislocation in the second order: avoiding the cut-off at the core

    International Nuclear Information System (INIS)

    Malyshev, C

    2007-01-01

    A translational gauge approach of the Einstein type is proposed for obtaining the stresses that are due to non-singular screw dislocation. The stress distribution of the second order around the screw dislocation is classically known for the hollow circular cylinder with traction-free external and internal boundaries. The inner boundary surrounds the dislocation's core, which is not captured by the conventional solution. The present gauge approach enables us to continue the classically known quadratic stresses inside the core. The gauge equation is chosen in the Hilbert-Einstein form, and it plays the role of non-conventional incompatibility law. The stress function method is used, and it leads to the modified stress potential given by two constituents: the conventional one, say, the 'background' and a short-ranged gauge contribution. The latter just causes additional stresses, which are localized. The asymptotic properties of the resulting stresses are studied. Since the gauge contributions are short-ranged, the background stress field dominates sufficiently far from the core. The outer cylinder's boundary is traction-free. At sufficiently moderate distances, the second-order stresses acquire regular continuation within the core region, and the cut-off at the core does not occur. Expressions for the asymptotically far stresses provide self-consistently new length scales dependent on the elastic parameters. These lengths could characterize an exteriority of the dislocation core region

  18. Anti-symmetric rank-two tensor matter field on superspace for N{sub T}=2

    Energy Technology Data Exchange (ETDEWEB)

    Spalenza, Wesley; Ney, Wander G; Helayel-Neto, J A

    2004-05-06

    In this work, we discuss the interaction between anti-symmetric rank-two tensor matter and topological Yang-Mills fields. The matter field considered here is the rank-2 Avdeev-Chizhov tensor matter field in a suitably extended N{sub T}=2 SUSY. We start off from the N{sub T}=2, D=4 superspace formulation and we go over to Riemannian manifolds. The matter field is coupled to the topological Yang-Mills field. We show that both actions are obtained as Q-exact forms, which allows us to express the energy-momentum tensor as Q-exact observables.

  19. Large tensor mode, field range bound and consistency in generalized G-inflation

    International Nuclear Information System (INIS)

    Kunimitsu, Taro; Suyama, Teruaki; Watanabe, Yuki; Yokoyama, Jun'ichi

    2015-01-01

    We systematically show that in potential driven generalized G-inflation models, quantum corrections coming from new physics at the strong coupling scale can be avoided, while producing observable tensor modes. The effective action can be approximated by the tree level action, and as a result, these models are internally consistent, despite the fact that we introduced new mass scales below the energy scale of inflation. Although observable tensor modes are produced with sub-strong coupling scale field excursions, this is not an evasion of the Lyth bound, since the models include higher-derivative non-canonical kinetic terms, and effective rescaling of the field would result in super-Planckian field excursions. We argue that the enhanced kinetic term of the inflaton screens the interactions with other fields, keeping the system weakly coupled during inflation

  20. Large tensor mode, field range bound and consistency in generalized G-inflation

    Energy Technology Data Exchange (ETDEWEB)

    Kunimitsu, Taro; Suyama, Teruaki; Watanabe, Yuki; Yokoyama, Jun' ichi, E-mail: kunimitsu@resceu.s.u-tokyo.ac.jp, E-mail: suyama@resceu.s.u-tokyo.ac.jp, E-mail: watanabe@resceu.s.u-tokyo.ac.jp, E-mail: yokoyama@resceu.s.u-tokyo.ac.jp [Research Center for the Early Universe, Graduate School of Science, The University of Tokyo, Tokyo 113-0033 (Japan)

    2015-08-01

    We systematically show that in potential driven generalized G-inflation models, quantum corrections coming from new physics at the strong coupling scale can be avoided, while producing observable tensor modes. The effective action can be approximated by the tree level action, and as a result, these models are internally consistent, despite the fact that we introduced new mass scales below the energy scale of inflation. Although observable tensor modes are produced with sub-strong coupling scale field excursions, this is not an evasion of the Lyth bound, since the models include higher-derivative non-canonical kinetic terms, and effective rescaling of the field would result in super-Planckian field excursions. We argue that the enhanced kinetic term of the inflaton screens the interactions with other fields, keeping the system weakly coupled during inflation.

  1. Charged tensor matter fields and Lorentz symmetry violation via spontaneous symmetry breaking

    International Nuclear Information System (INIS)

    Colatto, L.P.; Penna, A.L.A.; Santos, W.C.

    2003-10-01

    We consider a model with a charged vector field along with a Cremmer-Scherk-Kalb-Ramond (CSKR) matter field coupled to a U(1) gauge potential. We obtain a natural Lorentz symmetry violation due to the local U(1) spontaneous symmetry breaking mechanism triggered by the imaginary part of the vector matter. The choice of the unitary gauge leads to the decoupling of the gauge-Kr sector from the Higgs-Kr sector. The excitation spectrum is carefully analyzed and the physical modes are identified. We propose an identification of the neutral massive spin-1 Higgs-like field with the massive Z' boson of the so-called mirror matter models. (author)

  2. Consistent equations for interacting gauge fields of all spins in 3+1 dimensions

    Energy Technology Data Exchange (ETDEWEB)

    Vasiliev, M A [AN SSSR, Moscow. Inst. Teoreticheskoj Fiziki (USSR)

    1990-07-05

    Consistent equations of motion of interacting gauge fields of all spins in 3+1 dimensions are formulated in a closed form. These equations are explicitly general coordinate invariant, possess all necessary higher spin gauge symmetries and reduce to the usual equations of free massless fields of all spins s=0, 1/2, 1, ..., {infinity} at the linearized level. In the spin-2 sector, the proposed equations are equivalent to the Einstein equations with the cosmological term. (orig.).

  3. Decoupling Subtraction Conserving Full Gauge Symmetries : Particles and Fields

    OpenAIRE

    Noriyasu, OHTSUBO; Hideo, MIYATA; Department of Phycics, Kanazawa Technical College; Department of Information Science, Kanazawa Institute of Technolgy

    1984-01-01

    A new subtraction scheme (^^^) which realizes the decoupling and conserves the symmetries of full gauge group simultaneously, is proposed. One particle irreducible Green's functions subtracted by ^^^ reveal the effective low energy symmetries at -p^2≪M^2 and the full symmetries at -p^2≫M^2, where M denotes a heavy mass. Also discussed are conditions in order to carry out ^^^ under two-loop approximation.

  4. Blockspin and multigrid for staggered fermions in non-abelian gauge fields

    International Nuclear Information System (INIS)

    Kalkreuter, T.; Mack, G.; Speh, M.

    1991-07-01

    We discuss blockspins for staggered fermions, i.e. averaging and interpolation procedures which are needed in a real space renormalization group approach to gauge theories with staggered fermions and in a multigrid approach to the computation of gauge covariant propagators. The discussion starts from the requirement that the symmetries of the free action should be preserved by the blocking procedure in the limit of a pure gauge. A definition of an averaging kernel as a solution of a gauge covariant eigenvalue equation is proposed, and the properties of a corresponding interpolation kernel are examined in the light of general criteria for good choices of blockspins. Some results of multigrid computation of bosonic propagation in an SU(2) gauge field in 4 dimensions are also presented. (orig.)

  5. Gauge bridges in classical field theory; Eichbruecken in der klassischen Feldtheorie

    Energy Technology Data Exchange (ETDEWEB)

    Jakobs, S.

    2009-03-15

    In this thesis Poisson structures of two classical gauge field theories (Maxwell-Klein-Gordon- and Maxwell-Dirac-system) are constructed using the parametrix construction of Green's functions. Parametrices for the Maxwell-Klein-Gordon- and Maxwell-Dirac-system are constructed in Minkowski space and this construction is later generalized to curved space times for the Maxwell-Klein-Gordon-system. With these Green's functions Poisson brackets will be defined as Peierls brackets. Finally non-local, gauge invariant observables, the so-called 'gauge bridges'are constructed. Gauge bridges are the matrix elements of holonomy operators. It is shown, that these emerge from Poisson brackets of local, gauge invariant observables. (orig.)

  6. Gauged N=8 supergravity in five dimensions

    International Nuclear Information System (INIS)

    Guenaydin, M.; Romans, L.J.; Warner, N.P.

    1985-01-01

    We construct gauged N=8 supergravity theories in five dimensions. Instead of the twenty-seven vector fields of the ungauged theory, the gauged theories contain fifteen vector fields and twelve second-rank antisymmetric tensor fields satisfying self-dual field equations. The fifteen vector fields can be used to gauge any of the fifteen-dimensional semisimple subgroups of SL(6, R), sepcifically SO(p, 6-p) for p=0, 1, 2, 3. The gauged theories also have a physical global SU(1,1) symmetry which survives from the Esub(6(6)) symmetry of the ungauged theory. This SU(1, 1) for the SO(6) gauging is presumably related to that of the chiral N=2 theory in ten dimensions. In our formalism we maintain a composite local USp(8) symmetry analogous to SU(8) in four dimensions. (orig.)

  7. Renormalization of gauge theories in the background-field approach arXiv

    CERN Document Server

    Barvinsky, Andrei O.; Herrero-Valea, Mario; Sibiryakov, Sergey M.; Steinwachs, Christian F.

    Using the background-field method we demonstrate the Becchi-Rouet-Stora-Tyutin (BRST) structure of counterterms in a broad class of gauge theories. Put simply, we show that gauge invariance is preserved by renormalization in local gauge field theories whenever they admit a sensible background-field formulation and anomaly-free path integral measure. This class encompasses Yang-Mills theories (with possibly Abelian subgroups) and relativistic gravity, including both renormalizable and non-renormalizable (effective) theories. Our results also hold for non-relativistic models such as Yang-Mills theories with anisotropic scaling or Horava gravity. They strengthen and generalize the existing results in the literature concerning the renormalization of gauge systems. Locality of the BRST construction is emphasized throughout the derivation. We illustrate our general approach with several explicit examples.

  8. Theory of a gauge gravitational field at localization of the Einstein group

    International Nuclear Information System (INIS)

    Tunyak, V.N.

    1985-01-01

    Theory of a gauge gravitational field when localizing a group of movements of the Einstein homogeneous static Universe (the R x SO Einstein group (4)) has been formulated. Proceeding from tetrade components of the Einstein Universe the relation between the Riemann metrics and gauge fields of the Einstein group has been established. Metric coherence with torsion transforming to the Kristoffel coherence of the Einstein Universe has been found when switching out gauge fields. It is shown that within the limit of infinite radius of the Einstein Universe curvature the given Einstein-invariant gauge theory transforms to the tetrade gravitation theory with localized triade rotations. Exact solutions in the form of nonsingular cosmological models have been obtained

  9. A note on tensor fields in Hilbert spaces

    Directory of Open Access Journals (Sweden)

    LEONARDO BILIOTTI

    2002-06-01

    Full Text Available We discuss and extend to infinite dimensional Hilbert spaces a well-known tensoriality criterion for linear endomorphisms of the space of smooth vector fields in n.Discutimos e estendemos para espaços de Hilbert um critério de tensorialidade para endomorfismos do espaço dos campos vetoriais em Rpot(n.

  10. On the computation of the demagnetization tensor field for an arbitrary particle shape using a Fourier space approach

    International Nuclear Information System (INIS)

    Beleggia, M.; Graef, M. de

    2003-01-01

    A method is presented to compute the demagnetization tensor field for uniformly magnetized particles of arbitrary shape. By means of a Fourier space approach it is possible to compute analytically the Fourier representation of the demagnetization tensor field for a given shape. Then, specifying the direction of the uniform magnetization, the demagnetizing field and the magnetostatic energy associated with the particle can be evaluated. In some particular cases, the real space representation is computable analytically. In general, a numerical inverse fast Fourier transform is required to perform the inversion. As an example, the demagnetization tensor field for the tetrahedron will be given

  11. Voltage tensor for a plasma in high frequency electromagnetic and constant electric fields in the presence of collisions

    International Nuclear Information System (INIS)

    Vigdorchik, N.E.

    1978-01-01

    The voltage tensor expression is obtained for plasma placed in a HF electromagnetic and constant electric fields. The kinetic equations with allowance for collisions are initial. Weakly ionized and completely ionized plasmas are considered. The voltage tensor for completely ionized plasma differs essentially from that for transparent media

  12. Nonperturbative scale anomaly and composite operators in gauge field theories

    International Nuclear Information System (INIS)

    Gusynin, V.P.; Miranskij, V.A.

    1987-01-01

    In non-asymptotically free gauge theories with a non-trivial ultraviolet fixed point scale symmetry breaking (the scale anomaly) caused by the nonperturbative PCAC dynamics is studied. In the two-loop approximation the analytical expression for the gluon condensate is obtained. It is shown that the form of the anomaly depends on the type of the phase of a theory to which it relates. The hypothesis about the soft behaviour at small distances of composite operators in such theories is confirmed. 14 refs.; 1 fig

  13. Root Structures of Infinite Gauge Groups and Supersymmetric Field Theories

    International Nuclear Information System (INIS)

    Catto, Sultan; Gürcan, Yasemin; Khalfan, Amish; Kurt, Levent

    2013-01-01

    We show the relationship between critical dimensions of supersymmetric fundamental theories and dimensions of certain Jordan algebras. In our approach position vectors in spacetime or in superspace are endowed with algebraic properties that are present only in those critical dimensions. A uniform construction of super Poincaré groups in these dimensions will be shown. Some applications of these algebraic methods to hidden symmetries present in the covariant and interacting string Lagrangians and to superparticle will be discussed. Algebraic methods we develop will be shown to generate the root structure of some infinite groups that play the role of gauge groups in a second quantized theory of strings

  14. Gauge-fields and integrated quantum-classical theory

    International Nuclear Information System (INIS)

    Stapp, H.P.

    1986-01-01

    Physical situations in which quantum systems communicate continuously to their classically described environment are not covered by contemporary quantum theory, which requires a temporary separation of quantum degrees of freedom from classical ones. A generalization would be needed to cover these situations. An incomplete proposal is advanced for combining the quantum and classical degrees of freedom into a unified objective description. It is based on the use of certain quantum-classical structures of light that arise from gauge invariance to coordinate the quantum and classical degrees of freedom. Also discussed is the question of where experimenters should look to find phenomena pertaining to the quantum-classical connection. 17 refs

  15. Gaussian mixtures on tensor fields for segmentation: applications to medical imaging.

    Science.gov (United States)

    de Luis-García, Rodrigo; Westin, Carl-Fredrik; Alberola-López, Carlos

    2011-01-01

    In this paper, we introduce a new approach for tensor field segmentation based on the definition of mixtures of Gaussians on tensors as a statistical model. Working over the well-known Geodesic Active Regions segmentation framework, this scheme presents several interesting advantages. First, it yields a more flexible model than the use of a single Gaussian distribution, which enables the method to better adapt to the complexity of the data. Second, it can work directly on tensor-valued images or, through a parallel scheme that processes independently the intensity and the local structure tensor, on scalar textured images. Two different applications have been considered to show the suitability of the proposed method for medical imaging segmentation. First, we address DT-MRI segmentation on a dataset of 32 volumes, showing a successful segmentation of the corpus callosum and favourable comparisons with related approaches in the literature. Second, the segmentation of bones from hand radiographs is studied, and a complete automatic-semiautomatic approach has been developed that makes use of anatomical prior knowledge to produce accurate segmentation results. Copyright © 2010 Elsevier Ltd. All rights reserved.

  16. A pseudospectral matrix method for time-dependent tensor fields on a spherical shell

    International Nuclear Information System (INIS)

    Brügmann, Bernd

    2013-01-01

    We construct a pseudospectral method for the solution of time-dependent, non-linear partial differential equations on a three-dimensional spherical shell. The problem we address is the treatment of tensor fields on the sphere. As a test case we consider the evolution of a single black hole in numerical general relativity. A natural strategy would be the expansion in tensor spherical harmonics in spherical coordinates. Instead, we consider the simpler and potentially more efficient possibility of a double Fourier expansion on the sphere for tensors in Cartesian coordinates. As usual for the double Fourier method, we employ a filter to address time-step limitations and certain stability issues. We find that a tensor filter based on spin-weighted spherical harmonics is successful, while two simplified, non-spin-weighted filters do not lead to stable evolutions. The derivatives and the filter are implemented by matrix multiplication for efficiency. A key technical point is the construction of a matrix multiplication method for the spin-weighted spherical harmonic filter. As example for the efficient parallelization of the double Fourier, spin-weighted filter method we discuss an implementation on a GPU, which achieves a speed-up of up to a factor of 20 compared to a single core CPU implementation

  17. Lattice implementation of Abelian gauge theories with Chern-Simons number and an axion field

    Science.gov (United States)

    Figueroa, Daniel G.; Shaposhnikov, Mikhail

    2018-01-01

    Real time evolution of classical gauge fields is relevant for a number of applications in particle physics and cosmology, ranging from the early Universe to dynamics of quark-gluon plasma. We present an explicit non-compact lattice formulation of the interaction between a shift-symmetric field and some U (1) gauge sector, a (x)FμνF˜μν, reproducing the continuum limit to order O (dxμ2) and obeying the following properties: (i) the system is gauge invariant and (ii) shift symmetry is exact on the lattice. For this end we construct a definition of the topological number density K =FμνF˜μν that admits a lattice total derivative representation K = Δμ+ Kμ, reproducing to order O (dxμ2) the continuum expression K =∂μKμ ∝ E → ṡ B → . If we consider a homogeneous field a (x) = a (t), the system can be mapped into an Abelian gauge theory with Hamiltonian containing a Chern-Simons term for the gauge fields. This allow us to study in an accompanying paper the real time dynamics of fermion number non-conservation (or chirality breaking) in Abelian gauge theories at finite temperature. When a (x) = a (x → , t) is inhomogeneous, the set of lattice equations of motion do not admit however a simple explicit local solution (while preserving an O (dxμ2) accuracy). We discuss an iterative scheme allowing to overcome this difficulty.

  18. Lattice implementation of Abelian gauge theories with Chern–Simons number and an axion field

    Directory of Open Access Journals (Sweden)

    Daniel G. Figueroa

    2018-01-01

    Full Text Available Real time evolution of classical gauge fields is relevant for a number of applications in particle physics and cosmology, ranging from the early Universe to dynamics of quark–gluon plasma. We present an explicit non-compact lattice formulation of the interaction between a shift-symmetric field and some U(1 gauge sector, a(xFμνF˜μν, reproducing the continuum limit to order O(dxμ2 and obeying the following properties: (i the system is gauge invariant and (ii shift symmetry is exact on the lattice. For this end we construct a definition of the topological number density K=FμνF˜μν that admits a lattice total derivative representation K=Δμ+Kμ, reproducing to order O(dxμ2 the continuum expression K=∂μKμ∝E→⋅B→. If we consider a homogeneous field a(x=a(t, the system can be mapped into an Abelian gauge theory with Hamiltonian containing a Chern–Simons term for the gauge fields. This allow us to study in an accompanying paper the real time dynamics of fermion number non-conservation (or chirality breaking in Abelian gauge theories at finite temperature. When a(x=a(x→,t is inhomogeneous, the set of lattice equations of motion do not admit however a simple explicit local solution (while preserving an O(dxμ2 accuracy. We discuss an iterative scheme allowing to overcome this difficulty.

  19. Time evolution of linearized gauge field fluctuations on a real-time lattice

    Energy Technology Data Exchange (ETDEWEB)

    Kurkela, A. [CERN, Theoretical Physics Department, Geneva (Switzerland); University of Stavanger, Faculty of Science and Technology, Stavanger (Norway); Lappi, T. [University of Jyvaeskylae, Department of Physics, P.O. Box 35, Jyvaeskylae (Finland); University of Helsinki, Helsinki Institute of Physics, P.O. Box 64, Helsinki (Finland); Peuron, J. [University of Jyvaeskylae, Department of Physics, P.O. Box 35, Jyvaeskylae (Finland)

    2016-12-15

    Classical real-time lattice simulations play an important role in understanding non-equilibrium phenomena in gauge theories and are used in particular to model the prethermal evolution of heavy-ion collisions. Due to instabilities, small quantum fluctuations on top of the classical background may significantly affect the dynamics of the system. In this paper we argue for the need for a numerical calculation of a system of classical gauge fields and small linearized fluctuations in a way that keeps the separation between the two manifest. We derive and test an explicit algorithm to solve these equations on the lattice, maintaining gauge invariance and Gauss' law. (orig.)

  20. Time evolution of linearized gauge field fluctuations on a real-time lattice

    CERN Document Server

    Kurkela, Aleksi; Peuron, Jarkko

    2016-01-01

    Classical real-time lattice simulations play an important role in understanding non-equilibrium phenomena in gauge theories and are used in particular to model the prethermal evolution of heavy-ion collisions. Due to instabilities, small quantum fluctuations on top of the classical background may significantly affect the dynamics of the system. In this paper we argue for the need for a numerical calculation of a system of classical gauge fields and small linearized fluctuations in a way that keeps the separation between the two manifest. We derive and test an explicit algorithm to solve these equations on the lattice, maintaining gauge invariance and Gauss's law.

  1. Representation of a gauge field via intrinsic “BRST” operator

    Energy Technology Data Exchange (ETDEWEB)

    Batalin, Igor A., E-mail: batalin@lpi.ru [P.N. Lebedev Physical Institute, Leninsky Prospect 53, 119 991 Moscow (Russian Federation); Tomsk State Pedagogical University, Kievskaya St. 60, 634061 Tomsk (Russian Federation); Lavrov, Peter M., E-mail: lavrov@tspu.edu.ru [Tomsk State Pedagogical University, Kievskaya St. 60, 634061 Tomsk (Russian Federation); National Research Tomsk State University, Lenin Ave. 36, 634050 Tomsk (Russian Federation)

    2015-11-12

    We show that there exists a representation of a matrix-valued gauge field via intrinsic “BRST” operator assigned to matrix-valued generators of a gauge algebra. In this way, we reproduce the standard formulation of the ordinary Yang–Mills theory. In the case of a generating quasigroup/groupoid, we give a natural counterpart to the Yang–Mills action. The latter counterpart does also apply as to the most general case of an involution for matrix-valued gauge generators.

  2. Notes on Translational and Rotational Properties of Tensor Fields in Relativistic Quantum Mechanics

    Science.gov (United States)

    Dvoeglazov, V. V.

    Recently, several discussions on the possible observability of 4-vector fields have been published in literature. Furthermore, several authors recently claimed existence of the helicity=0 fundamental field. We re-examine the theory of antisymmetric tensor fields and 4-vector potentials. We study the massless limits. In fact, a theoretical motivation for this venture is the old papers of Ogievetskiĭ and Polubarinov, Hayashi, and Kalb and Ramond. Ogievetskiĭ and Polubarinov proposed the concept of the notoph, whose helicity properties are complementary to those of the photon. We analyze the quantum field theory with taking into account mass dimensions of the notoph and the photon. It appears to be possible to describe both photon and notoph degrees of freedom on the basis of the modified Bargmann-Wigner formalism for the symmetric second-rank spinor. Next, we proceed to derive equations for the symmetric tensor of the second rank on the basis of the Bargmann-Wigner formalism in a straightforward way. The symmetric multispinor of the fourth rank is used. Due to serious problems with the interpretation of the results obtained on using the standard procedure we generalize it and obtain the spin-2 relativistic equations, which are consistent with the general relativity. Thus, in fact we deduced the gravitational field equations from relativistic quantum mechanics. The relations of this theory with the scalar-tensor theories of gravitation and f(R) are discussed. Particular attention has been paid to the correct definitions of the energy-momentum tensor and other Nöther currents in the electromagnetic theory, the relativistic theory of gravitation, the general relativity, and their generalizations. We estimate possible interactions, fermion-notoph, graviton-notoph, photon-notoph, and we conclude that they can probably be seen in experiments in the next few years.

  3. Diffusion with finite-helicity field tensor: A mechanism of generating heterogeneity

    Science.gov (United States)

    Sato, N.; Yoshida, Z.

    2018-02-01

    Topological constraints on a dynamical system often manifest themselves as breaking of the Hamiltonian structure; well-known examples are nonholonomic constraints on Lagrangian mechanics. The statistical mechanics under such topological constraints is the subject of this study. Conventional arguments based on phase spaces, Jacobi identity, invariant measure, or the H theorem are no longer applicable since all these notions stem from the symplectic geometry underlying canonical Hamiltonian systems. Remembering that Hamiltonian systems are endowed with field tensors (canonical 2-forms) that have zero helicity, our mission is to extend the scope toward the class of systems governed by finite-helicity field tensors. Here, we introduce a class of field tensors that are characterized by Beltrami vectors. We prove an H theorem for this Beltrami class. The most general class of energy-conserving systems are non-Beltrami, for which we identify the "field charge" that prevents the entropy to maximize, resulting in creation of heterogeneous distributions. The essence of the theory can be delineated by classifying three-dimensional dynamics. We then generalize to arbitrary (finite) dimensions.

  4. The total energy-momentum tensor for electromagnetic fields in a dielectric

    Science.gov (United States)

    Crenshaw, Michael E.

    2017-08-01

    Radiation pressure is an observable consequence of optically induced forces on materials. On cosmic scales, radiation pressure is responsible for the bending of the tails of comets as they pass near the sun. At a much smaller scale, optically induced forces are being investigated as part of a toolkit for micromanipulation and nanofabrication technology [1]. A number of practical applications of the mechanical effects of light-matter interaction are discussed by Qiu, et al. [2]. The promise of the nascent nanophotonic technology for manufacturing small, low-power, high-sensitivity sensors and other devices has likely motivated the substantial current interest in optical manipulation of materials at the nanoscale, see, for example, Ref. [2] and the references therein. While substantial progress toward optical micromanipulation has been achieved, e.g. optical tweezers [1], in this report we limit our consideration to the particular issue of optically induced forces on a transparent dielectric material. As a matter of electromagnetic theory, these forces remain indeterminate and controversial. Due to the potential applications in nanotechnology, the century-old debate regarding these forces, and the associated momentums, has ramped up considerably in the physics community. The energy-momentum tensor is the centerpiece of conservation laws for the unimpeded, inviscid, incompressible flow of non-interacting particles in the continuum limit in an otherwise empty volume. The foundations of the energy-momentum tensor and the associated tensor conservation theory come to electrodynamics from classical continuum dynamics by applying the divergence theorem to a Taylor series expansion of a property density field of a continuous flow in an otherwise empty volume. The dust tensor is a particularly simple example of an energy-momentum tensor that deals with particles of matter in the continuum limit in terms of the mass density ρm, energy density ρmc 2 , and momentum density

  5. On the motion of matter in the geometrical gauge field theory

    International Nuclear Information System (INIS)

    Konopleva, N.P.

    2005-01-01

    In the geometrical gauge field theory, the motion equations of matter (elementary particles) are connected with the field equations. The problems arising from this connection are discussed. For the first time, such problems arose in Einstein's General Relativity. Einstein hoped that solution of these problems will allow explanation of elementary particles nature without making use of quantum mechanics. But, as it turned out, the situation is more difficult. Here the corresponding problems are formulated for the connection of equations of particle motion and field equations in the geometrical gauge field theory. It is shown that appearance of the problems under discussion is an inevitable effect of passage to relativism and local symmetries

  6. Model of unified gauge fields; Le modele des champs de jauge unifies

    Energy Technology Data Exchange (ETDEWEB)

    Leite Lopes, J. [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil)

    1998-04-01

    In this work, we discuss the physical ideas which represents the basis for the unified gauge field model. Despite of the difficulties that we presently have for embodying in a natural manner muons and hadrons in that model, we have the feeling that we are on the way which seems to lead to the construction of a theory in which the Maxwell electromagnetic field and the Fermi weak interaction field are manifestations of a unique subjacent physical entity - the unified gauge fields. (author) 22 refs., 6 figs.

  7. Recent developments in chiral gauge theories: approach of infinitely many fermi fields

    International Nuclear Information System (INIS)

    Narayanan, R.

    1994-01-01

    I present the recent developments in a specific sub-field of chiral gauge theories on the lattice. This subfield pertains to the use of infinitely many fermi fields to describe a single chiral field. In this approach, both anomalous and anomaly free theories can be discussed in equal footing. It produces the correct anomaly in the continuum limit. It has the potential to describe fermion number violating processes in the presence of a gauge field background with non-trivial topological charge on a finite lattice. (orig.)

  8. 2PI effective action for the SYK model and tensor field theories

    Science.gov (United States)

    Benedetti, Dario; Gurau, Razvan

    2018-05-01

    We discuss the two-particle irreducible (2PI) effective action for the SYK model and for tensor field theories. For the SYK model the 2PI effective action reproduces the bilocal reformulation of the model without using replicas. In general tensor field theories the 2PI formalism is the only way to obtain a bilocal reformulation of the theory, and as such is a precious instrument for the identification of soft modes and for possible holographic interpretations. We compute the 2PI action for several models, and push it up to fourth order in the 1 /N expansion for the model proposed by Witten in [1], uncovering a one-loop structure in terms of an auxiliary bilocal action.

  9. Gauge invariant lattice quantum field theory: Implications for statistical properties of high frequency financial markets

    Science.gov (United States)

    Dupoyet, B.; Fiebig, H. R.; Musgrove, D. P.

    2010-01-01

    We report on initial studies of a quantum field theory defined on a lattice with multi-ladder geometry and the dilation group as a local gauge symmetry. The model is relevant in the cross-disciplinary area of econophysics. A corresponding proposal by Ilinski aimed at gauge modeling in non-equilibrium pricing is implemented in a numerical simulation. We arrive at a probability distribution of relative gains which matches the high frequency historical data of the NASDAQ stock exchange index.

  10. Ground-state projection multigrid for propagators in 4-dimensional SU(2) gauge fields

    International Nuclear Information System (INIS)

    Kalkreuter, T.

    1991-09-01

    The ground-state projection multigrid method is studied for computations of slowly decaying bosonic propagators in 4-dimensional SU(2) lattice gauge theory. The defining eigenvalue equation for the restriction operator is solved exactly. Although the critical exponent z is not reduced in nontrivial gauge fields, multigrid still yields considerable speedup compared with conventional relaxation. Multigrid is also able to outperform the conjugate gradient algorithm. (orig.)

  11. From the Berlin "Entwurf" Field Equations to the Einstein Tensor III: March 1916

    OpenAIRE

    Weinstein, Galina

    2012-01-01

    I discuss Albert Einstein's 1916 General Theory of Relativity. I show that in Einstein's 1916 review paper, "the Foundation of the General Theory of Relativity", he derived his November 25, 1915 field equations with an additional term on the right hand side involving the trace of the energy-momentum tensor (he posed the condition square root -g=1) using the equations he presented on November 4, 1915. Series of papers: Final paper.

  12. A study of the path-integral quantization of Abelian gauge theories when no explicit gauge-fixing term is included in the bilinear part of the gauge-field action

    International Nuclear Information System (INIS)

    Phillips, S.

    1985-01-01

    The mathematical problem of inverting the operator Δ x μν ≡ g μν g αβ δ x α δ x β -δ x μ δ x ν , as it arises in the path-integral quantization of an Abelian gauge theory, such as quantum electrodynamics, when no gauge-fixing Lagrangian field density is included, is studied in this article. Making use of the fact that the Schwinger source functions, which are introduced for the purpose of generating Green's functions, are free of divergence, a result that follows from the conversion of the exponentiated action into a Gaussian form, the apparently noninvertible partial differential equation, Δ x μν L ν (x) J μ (x), can, by the addition and subsequent subtraction of terms containing the divergence of the source function, be cast into a form that does possess a Green's function solution. The gauge-field propagator is the same as that obtained by the conventional technique, which involves gauge fixing when the gauge parameter, α, is set equal to one. Such an analysis suggests also that, provided the effect of fictitious particles that propagate only in closed loops are included for the study of Green's functions in non-Abelian gauge theories in Landau-type gauges, then, in quantizing either Abelian gauge theories or non-Abelian gauge theories in this generic kind of gauge, it is not necessary to add an explicit gauge-fixing term to the bilinear part of the gauge-field action

  13. Incompressible Steady Flow with Tensor Conductivity Leaving a Transverse Magnetic Field

    International Nuclear Information System (INIS)

    Witalis, E.A.

    1965-12-01

    The straight channel flow of an inviscid, incompressible fluid with tensor conductivity is considered when the flow leaves a region of constant transverse magnetic field. The channel walls are taken to be insulating, and an eddy current system arises. This is investigated by the method of magnetic field analysis as given by Witalis. The spatial distribution of magnetic field and ohmic power loss, both parallel and transverse to the flow, are given as functions of the Hall parameter with consideration also to the magnetic Reynolds number of the fluid. MHD power generator aspects of this problem and the results are discussed

  14. Incompressible Steady Flow with Tensor Conductivity Leaving a Transverse Magnetic Field

    Energy Technology Data Exchange (ETDEWEB)

    Witalis, E A

    1965-12-15

    The straight channel flow of an inviscid, incompressible fluid with tensor conductivity is considered when the flow leaves a region of constant transverse magnetic field. The channel walls are taken to be insulating, and an eddy current system arises. This is investigated by the method of magnetic field analysis as given by Witalis. The spatial distribution of magnetic field and ohmic power loss, both parallel and transverse to the flow, are given as functions of the Hall parameter with consideration also to the magnetic Reynolds number of the fluid. MHD power generator aspects of this problem and the results are discussed.

  15. Spontaneous symmetry breaking in local gauge quantum field theory; the Higgs mechanism

    International Nuclear Information System (INIS)

    Strocchi, F.

    1977-01-01

    Spontaneous symmetry breakings in indefinite metric quantum field theories are analyzed and a generalization of the Goldstone theorem is proved. The case of local gauge quantum field theories is discussed in detail and a characterization is given of the occurrence of the Higgs mechanism versus the Goldstone mechanism. The Higgs phenomenon is explained on general grounds without the introduction of the so-called Higgs fields. The basic property is the relation between the local internal symmetry group and the local group of gauge transformations of the second kind. Spontaneous symmetry breaking of c-number gauge transformations of the second kind is shown to always occur if there are charged local fields. The implications about the absence of mass gap in the Wightman functions and the occurrence of massless particles associated with the unbroken generators in the Higgs phenomenon are discussed. (orig.) [de

  16. Algebraic computing program for studying the gauge theory

    International Nuclear Information System (INIS)

    Zet, G.

    2005-01-01

    An algebraic computing program running on Maple V platform is presented. The program is devoted to the study of the gauge theory with an internal Lie group as local symmetry. The physical quantities (gauge potentials, strength tensors, dual tensors etc.) are introduced either as equations in terms of previous defined quantities (tensors), or by manual entry of the component values. The components of the strength tensor and of its dual are obtained with respect to a given metric of the space-time used for describing the gauge theory. We choose a Minkowski space-time endowed with spherical symmetry and give some example of algebraic computing that are adequate for studying electroweak or gravitational interactions. The field equations are also obtained and their solutions are determined using the DEtools facilities of the Maple V computing program. (author)

  17. 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.

  18. Improved tensor multiplets

    International Nuclear Information System (INIS)

    Wit, B. de; Rocek, M.

    1982-01-01

    We construct a conformally invariant theory of the N = 1 supersymmetric tensor gauge multiplet and discuss the situation in N = 2. We show that our results give rise to the recently proposed variant of Poincare supergravity, and provide the complete tensor calculus for the theory. Finally, we argue that this theory cannot be quantized sensibly. (orig.)

  19. Energy momentum tensor and marginal deformations in open string field theory

    International Nuclear Information System (INIS)

    Sen, Ashoke

    2004-01-01

    Marginal boundary deformations in a two dimensional conformal field theory correspond to a family of classical solutions of the equations of motion of open string field theory. In this paper we develop a systematic method for relating the parameter labelling the marginal boundary deformation in the conformal field theory to the parameter labelling the classical solution in open string field theory. This is done by first constructing the energy-momentum tensor associated with the classical solution in open string field theory using Noether method, and then comparing this to the answer obtained in the conformal field theory by analysing the boundary state. We also use this method to demonstrate that in open string field theory the tachyon lump solution on a circle of radius larger than one has vanishing pressure along the circle direction, as is expected for a co-dimension one D-brane. (author)

  20. A variational principle giving gravitational 'superpotentials', the affine connection, Riemann tensor, and Einstein field equations

    International Nuclear Information System (INIS)

    Stachel, J.

    1977-01-01

    A first-order Lagrangian is given, from which follow the definitions of the fully covariant form of the Riemann tensor Rsub(μνkappalambda) in terms of the affine connection and metric; the definition of the affine connection in terms of the metric; the Einstein field equations; and the definition of a set of gravitational 'superpotentials' closely connected with the Komar conservation laws (Phys. Rev.; 113:934 (1959)). Substitution of the definition of the affine connection into this Lagrangian results in a second-order Lagrangian, from which follow the definition of the fully covariant Riemann tensor in terms of the metric, the Einstein equations, and the definition of the gravitational 'superpotentials'. (author)

  1. Multipole analysis in the radiation field for linearized f (R ) gravity with irreducible Cartesian tensors

    Science.gov (United States)

    Wu, Bofeng; Huang, Chao-Guang

    2018-04-01

    The 1 /r expansion in the distance to the source is applied to the linearized f (R ) gravity, and its multipole expansion in the radiation field with irreducible Cartesian tensors is presented. Then, the energy, momentum, and angular momentum in the gravitational waves are provided for linearized f (R ) gravity. All of these results have two parts, which are associated with the tensor part and the scalar part in the multipole expansion of linearized f (R ) gravity, respectively. The former is the same as that in General Relativity, and the latter, as the correction to the result in General Relativity, is caused by the massive scalar degree of freedom and plays an important role in distinguishing General Relativity and f (R ) gravity.

  2. Vacuum stress tensor of a scalar field in a rectangular waveguide

    International Nuclear Information System (INIS)

    Rodrigues, R.B.; Svaiter, N.F.; Paola, R.D.M. de

    2001-11-01

    Using the heat Kernel method and the analytical continuation of the zeta function, we calculate the canonical and improved vacuum stress tensors, {T μν (vector x)} and {Θ μν (vector x)}, associated with a massless scalar field confined in the interior of an infinity long rectangular waveguide. The local depence of the renormalized energy for two special configurations when the total energy is positive and negative are presented using {T 00 (vector x)} and {Θ 00 (vector x)}. From the stress tensors we obtain the local casimir forces in all walls by introducing a particular external configuration. It is hown that this external configuration cannot give account of the edge divergences of the local forces. The local form of the forces is obtained for three special configurations. (author)

  3. Invariance identities associated with finite gauge transformations and the uniqueness of the equations of motion of a particle in a classical gauge field

    International Nuclear Information System (INIS)

    Rund, H.

    1984-01-01

    A certain class of geometric objects is considered against the background of a classical gauge field associated with an arbitrary structural Lie group. It is shown that the necessary and sufficient conditions for the invariance of the given objects under a finite gauge transformation are embodied in a set of three relations involving the derivatives of their components. As a special case these so-called invariance identities indicate that there cannot exist a gauge-invariant Lagrangian that depends on the gauge potentials, the interaction parameters, and the 4-velocity components of a test particle. However, the requirement that the equations of motion that result from such a lagrangian be gauge-invariant, uniquely determines the structure of these equations. (author)

  4. Background field quantization in non-covariant gauges: Renormalization and WTST identities

    International Nuclear Information System (INIS)

    McKeon, G.; Phillips, S.B.; Samant, S.S.; Sherry, T.N.

    1986-01-01

    Background field quantization of pure YM theories in non-covariant gauges is treated with particular emphasis on renormalization. Gauge fixing terms of the form (1/2α)n . Qsup(a)fsup(ab)n . Qsup(b) are considered where fsup(ab) can assume the forms fsup(ab)sub((i))=-deltasup(ab) (the axial gauge), fsup(ab)sub((ii))=(n . D(A))sup(2ab)/n 4 and fsup(ab)sub((iii))=D 2 (A)sup(ab)/n 2 (the planar gauge). For the cases where fsup(ab) depends explicitly on the background field Asub(μ)sup(a) the ghost sector is enlarged by the addition of appropriate Nielson-Kallosh ghost fields. The BRS identities for these gauge choices are derived and solved. The quantum-corrected versions of both the bare background field gauge transformations and the bare quantum field gauge transformations are obtained from the BRS analysis. It is also shown that, to one loop, all the counter terms are determined by the background field independent part of the theory and this result is used, in cases (ii) and (iii), to derive all the counter terms and to show that Kallosh's theorem is verified. The result is also used to demonstrate the pathological nature of case (i) for αnot=0, in particular the result that Kallosh's theorem is not applicable. The result that the generating functional of Green functions is independent of the background field Asub(μ)sup(a) in the absence of all external sources is generalized to the case of non-covariant gauges. The equality established by Abbott between the 1PI generating functionals GAMMA tilde[A,0] and GAMMAsub(c)[anti Q; A] sub(anti Q=A), where GAMMAsub(c) is a conventional generating functional in an A-dependent gauge, is analysed. We show that the WTST identities satisfied by GAMMAsub(c) reduce, when anti Q is set equal to A, to the naive Ward-identity satisfied by GAMMA tilde[A,0]. (orig.)

  5. Dynamically broken gauge model without fundamental scalar fields

    International Nuclear Information System (INIS)

    Snyderman, N.J.; Guralnik, G.S.

    1976-01-01

    It is shown that the structure that must be generated by dynamical symmetry breaking solutions to gauge theories can be explicitly implemented with a 4-fermion interaction. This structure arises in order to obtain consistency with the constraints imposed by a Goldstone commutator proportional to [anti psi psi]. One demonstrates these ideas within the context of axial electrodynamics, dynamically breaking chiral symmetry. As a pre-requisite it is shown how the Nambu-Jona-Lasinio model becomes renormalizable with respect to a systematic approximation scheme that respects the Goldstone commutator of dynamically broken chiral symmetry to each order of approximation. (This approximation scheme is equivalent to a l/N expansion, where N is set to unity at the end of the calculations). This solution generates new interactions not explicitly present in the original Lagrangian and does not have a 4-fermion contact interaction. The renormalized Green's functions are shown to correspond to those of the sigma-model, summed as though the fermions had N components, and for which lambda 0 = 2g 0 2 . This correspondence is exact except for the possibility that the renormalized coupling of the Nambu-Jona-Lasinio model may be a determined number

  6. Dynamically broken gauge model without fundamental scalar fields

    Energy Technology Data Exchange (ETDEWEB)

    Snyderman, N. J.; Guralnik, G. S.

    1976-01-01

    It is shown that the structure that must be generated by dynamical symmetry breaking solutions to gauge theories can be explicitly implemented with a 4-fermion interaction. This structure arises in order to obtain consistency with the constraints imposed by a Goldstone commutator proportional to (anti psi psi). One demonstrates these ideas within the context of axial electrodynamics, dynamically breaking chiral symmetry. As a pre-requisite it is shown how the Nambu-Jona-Lasinio model becomes renormalizable with respect to a systematic approximation scheme that respects the Goldstone commutator of dynamically broken chiral symmetry to each order of approximation. (This approximation scheme is equivalent to a l/N expansion, where N is set to unity at the end of the calculations). This solution generates new interactions not explicitly present in the original Lagrangian and does not have a 4-fermion contact interaction. The renormalized Green's functions are shown to correspond to those of the sigma-model, summed as though the fermions had N components, and for which lambda/sub 0/ = 2g/sub 0//sup 2/. This correspondence is exact except for the possibility that the renormalized coupling of the Nambu-Jona-Lasinio model may be a determined number.

  7. Geometro-stochastic quantization of gauge fields in curved space-time

    International Nuclear Information System (INIS)

    Prugovecki, E.

    1988-01-01

    It is shown that the geometro-stochastic method of quantization of massive fields in curved space-time can be extended to the massless cases of electromagnetic fields and general Yang-Mills fields. The Fock fibres of the massive case are replaced in the present context by fibres with indefinite inner products, such as Gupta-Bleuler fibres in the electromagnetic case. The quantum space-time form factor used in the massive case gives rise in the present case to quantum gauge frames whose elements are generalized coherent states corresponding to pseudounitary spin-one representations of direct products of the Poincare group with the U(1), SU(N) or other internal gauge groups. Quantum connections are introduced on bundles of second-quantized frames, and the corresponding parallel transport is expressed in terms of path integrals for quantum frame propagators. In the Yang-Mills case, these path integral make use of Faddeev-Popov quantum frames. It is shown, however, that in the present framework the ghost fields that give rise to these frames possess a geometric interpretation related to the presence of a super-gauge group that, in addition to the external Poincare and Yang-Mills gauge degrees of freedom, involves also the internal ones related to choices of gauge bases within the quantum fibres

  8. Vacuum gauges

    International Nuclear Information System (INIS)

    Power, B.D.; Priestland, C.R.D.

    1978-01-01

    This invention relates to vacuum gauges, particularly of the type known as Penning gauges, which are cold cathode ionisation gauges, in which a magnetic field is used to lengthen the electron path and thereby increase the number of ions produced. (author)

  9. Gauge theories

    International Nuclear Information System (INIS)

    Lee, B.W.

    1976-01-01

    Some introductory remarks to Yang-Mills fields are given and the problem of the Coulomb gauge is considered. The perturbation expansion for quantized gauge theories is discussed and a survey of renormalization schemes is made. The role of Ward-Takahashi identities in gauge theories is discussed. The author then discusses the renormalization of pure gauge theories and theories with spontaneously broken symmetry. (B.R.H.)

  10. New approach to the problem of gauge field quantization

    International Nuclear Information System (INIS)

    Skachkov, N.B.; Shevchenko, O.Yu.

    1987-01-01

    A new scheme of calibration field quantization containing considerable change of the procedure of calibration conditions application on field variables is suggested. The above approach is based on a proved theorem on the subordination of fields to the additional Lorenz condition when applying a wide class of initial calibration conditions on these fields. This condition has the sense of the secondary bond, which must be included in the system of bonds during field quantization. The fact of secondary bond presence in the form of Lorenz condition was not earlier considered in literature and used in quantization. Due to this, the report suggests modification of all existing methods of field quantization: according to Dirac-Bergman, covariant approach using an indefinite metric and the method of functional integration

  11. Gauge invariant Lagrangian formulation of massive higher spin fields in (A)dS3 space

    International Nuclear Information System (INIS)

    Buchbinder, I.L.; Snegirev, T.V.; Zinoviev, Yu.M.

    2012-01-01

    We develop the frame-like formulation of massive bosonic higher spin fields in the case of three-dimensional (A)dS space with the arbitrary cosmological constant. The formulation is based on gauge invariant description by involving the Stueckelberg auxiliary fields. The explicit form of the Lagrangians and the gauge transformation laws are found. The theory can be written in terms of gauge invariant objects similar to the massless theories, thus allowing us to hope to use the same methods for investigation of interactions. In the massive spin 3 field example we are able to rewrite the Lagrangian using the new the so-called separated variables, so that the study of Lagrangian formulation reduces to finding the Lagrangian containing only half of the fields. The same construction takes places for arbitrary integer spin field as well. Further working in terms of separated variables, we build Lagrangian for arbitrary integer spin and write it in terms of gauge invariant objects. Also, we demonstrate how to restore the full set of variables, thus receiving Lagrangian for the massive fields of arbitrary spin in the terms of initial fields.

  12. Quantum fields interacting with colliding plane waves: the stress-energy tensor and backreaction

    International Nuclear Information System (INIS)

    Dorca, M.; Verdaguer, E.

    1997-01-01

    Following a previous work on the quantization of a massless scalar field in a space-time representing the head on collision of two plane waves which focus into a Killing-Cauchy horizon, we compute the renormalized expectation value of the stress-energy tensor of the quantum field near that horizon in the physical state which corresponds to the Minkowski vacuum before the collision of the waves. It is found that for minimally coupled and conformally coupled scalar fields the respective stress-energy tensors are unbounded in the horizon. The specific form of the divergences suggests that when the semiclassical Einstein equations describing the backreaction of the quantum fields on the space-time geometry are taken into account, the horizon will acquire a curvature singularity. Thus the Killing-Cauchy horizon which is known to be unstable under ''generic'' classical perturbations is also unstable by vacuum polarization. The calculation is done following the point-splitting regularization technique. The dynamical colliding wave space-time has four quite distinct space-time regions, namely, one flat region, two single plane wave regions, and one interaction region. Exact mode solutions of the quantum field equation cannot be found exactly, but the blueshift suffered by the initial modes in the plane wave and interaction regions makes the use of the WKB expansion a suitable method of solution. To ensure the correct regularization of the stress-energy tensor, the initial flat modes propagated into the interaction region must be given to a rather high adiabatic order of approximation. (orig.)

  13. Black-body radiation of noncommutative gauge fields

    International Nuclear Information System (INIS)

    Fatollahi, Amir H.; Hajirahimi, Maryam

    2006-01-01

    The black-body radiation is considered in a theory with noncommutative electRomegnetic fields; that is noncommutativity is introduced in field space, rather than in real space. A direct implication of the result on cosmic microwave background map is argued

  14. Field-strength formulation of gauge theories. The Hamiltonian approach in the Abelian theory

    International Nuclear Information System (INIS)

    Mendel, E.; Durand, L.

    1984-01-01

    We develop a Hamiltonian approach to the field-strength or dual formation of the Abelian gauge theory in which the potential A/sup μ/ is eliminated as a dynamical variable. Our work is based on the covariant gauge x/sup μ/A/sub μ/(x) = 0 which allows a simple elimination of A/sup μ/ in terms of the field strengths F/sup munu/. We obtain complete results for the generating functional for the Green's functions of the theory, Z = Z[f,g], where f and g are nonlocal currents coupled to E and B, and illustrate some unfamiliar aspects of the new formalism

  15. Problems of an external field in non-Abelian gauge theory

    International Nuclear Information System (INIS)

    Gavrilov, S.P.; Gitman, D.M.

    1992-01-01

    In the Abelian gauge field theory QED the principal problems connected with an external field are the problems of exact keeping of an external field in a perturbation theory and appearing in this case the peculiarities of the theory such as the instability of the vacuum and so on. There is the problem of an external field introduction or its interpretation side by side with this problem in Non-Abelian gauge theory. The solution of both these problems in Non-Abelian theory can be considered by analogy with QED. In the present paper, the authors discuss on the example of the spontaneously broken SU(2) x U(1) electroweak theory both the problems of an external field introduction and the problem of exact keeping of this field in the perturbation theory. The Langrangian of this theory in covariant gauge is chosen in the BRST invariant form. In spite of concrete character of the theory studied, the method can be extended to any gauge theory

  16. TensorLy: Tensor Learning in Python

    NARCIS (Netherlands)

    Kossaifi, Jean; Panagakis, Yannis; Pantic, Maja

    2016-01-01

    Tensor methods are gaining increasing traction in machine learning. However, there are scant to no resources available to perform tensor learning and decomposition in Python. To answer this need we developed TensorLy. TensorLy is a state of the art general purpose library for tensor learning.

  17. Topological gravity from a transgression gauge field theory

    International Nuclear Information System (INIS)

    Merino, N.; Perez, A.; Salgado, P.; Valdivia, O.

    2010-01-01

    It is shown that a topological action for gravity in even dimensions can be obtained from a gravity theory whose Lagrangian is given by a transgression form invariant under the Poincare group. The field φ a , which is necessary to construct this type of topological gravity in even dimensions, is identified with the coset field associated with the non-linear realizations of the Poincare group ISO(d-1,1).

  18. Dynamical chaos of non-Abelian gauge fields

    International Nuclear Information System (INIS)

    Matinyan, S.G.

    1985-01-01

    The review studies a special class of Yang--Mills fields: spatially homogeneous fields (classical Yang--Mills mechanics), which have no analog in linear Abelian electrodynamics. Computer and analytic approaches show that such fields possess dynamical stochasticity, on the basis of which it may be asserted that the classical Yang--Mills equations without external sources constitute a nonintegrable system. The Higgs mechanism eliminates this stochasticity, and at a certain value of the vacuum expectation of the scalar field there is a phase transition of the disorder-order (confinement-deconfinement) type. The system with external sources apparently behaves similarly. The connection between this stochasticity and the mechanism of dimensional reduction in macroscopic systems and with the color-confinement phenomenon is considered. It is shown that the presence in the vacuum of random (Gaussian) currents leads to confinement of the fields generated by these currents. Attention is drawn to the possible manifestation of the stochasticity of the classical fields in multiparticle hadron-production processes. Such manifestation reflects universal stochastic features characteristic of systems of very different natures (statistics of the counting of thermoelectrons from random sources and photoelectrons from laser radiation that passes through a liquid in the critical state, developed turbulence in hydrodynamics, stellar systems, and KNO scaling in multiparticle production)

  19. Supersymmetric gauged double field theory: systematic derivation by virtue of twist

    International Nuclear Information System (INIS)

    Cho, Wonyoung; Fernández-Melgarejo, J.J.; Jeon, Imtak; Park, Jeong-Hyuck

    2015-01-01

    In a completely systematic and geometric way, we derive maximal and half-maximal supersymmetric gauged double field theories in lower than ten dimensions. To this end, we apply a simple twisting ansatz to the D=10 ungauged maximal and half-maximal supersymmetric double field theories constructed previously within the so-called semi-covariant formalism. The twisting ansatz may not satisfy the section condition. Nonetheless, all the features of the semi-covariant formalism, including its complete covariantizability, are still valid after the twist under alternative consistency conditions. The twist allows gaugings as supersymmetry preserving deformations of the D=10 untwisted theories after Scherk-Schwarz-type dimensional reductions. The maximal supersymmetric twist requires an extra condition to ensure both the Ramond-Ramond gauge symmetry and the 32 supersymmetries unbroken.

  20. Gauge-invariant scalar and field strength correlators in 3d

    CERN Document Server

    Laine, Mikko

    1998-01-01

    Gauge-invariant non-local scalar and field strength operators have been argued to have significance, e.g., as a way to determine the behaviour of the screened static potential at large distances, as order parameters for confinement, as input parameters in models of confinement, and as gauge-invariant definitions of light constituent masses in bound state systems. We measure such "correlators" in the 3d pure SU(2) and SU(2)+Higgs models on the lattice. We extract the corresponding mass parameters and discuss their scaling and physical interpretation. We find that the finite part of the MS-bar scheme mass measured from the field strength correlator is large, more than half the glueball mass. We also determine the non-perturbative contribution to the Debye mass in the 4d finite T SU(2) gauge theory with a method due to Arnold and Yaffe, finding $\\delta m_D\\approx 1.06(4)g^2T$.

  1. Gravitational waves from Abelian gauge fields and cosmic strings at preheating

    International Nuclear Information System (INIS)

    Dufaux, Jean-Francois; Figueroa, Daniel G.; Garcia-Bellido, Juan

    2010-01-01

    Primordial gravitational waves provide a very important stochastic background that could be detected soon with interferometric gravitational wave antennas or indirectly via the induced patterns in the polarization anisotropies of the cosmic microwave background. The detection of these waves will open a new window into the early Universe, and therefore it is important to characterize in detail all possible sources of primordial gravitational waves. In this paper we develop theoretical and numerical methods to study the production of gravitational waves from out-of-equilibrium gauge fields at preheating. We then consider models of preheating after hybrid inflation, where the symmetry breaking field is charged under a local U(1) symmetry. We analyze in detail the dynamics of the system in both momentum and configuration space. We show that gauge fields leave specific imprints in the resulting gravitational wave spectra, mainly through the appearance of new peaks at characteristic frequencies that are related to the mass scales in the problem. We also show how these new features in the spectra correlate with stringlike spatial configurations in both the Higgs and gauge fields that arise due to the appearance of topological winding numbers of the Higgs around Nielsen-Olesen strings. We study in detail the time evolution of the spectrum of gauge fields and gravitational waves as these strings evolve and decay before entering a turbulent regime where the gravitational wave energy density saturates.

  2. Photon polarization tensor in the light front field theory at zero and finite temperatures

    International Nuclear Information System (INIS)

    Silva, Charles da Rocha; Perez, Silvana; Strauss, Stefan

    2012-01-01

    Full text: In recent years, light front quantized field theories have been successfully generalized to finite temperature. The light front frame was introduced by Dirac , and the quantization of field theories on the null-plane has found applications in many branches of physics. In order to obtain the thermal contribution, we consider the hard thermal loop approximation. This technique was developed by Braaten and Pisarski for the thermal quantum field theory at equal times and is particularly useful to extract the leading thermal contributions to the amplitudes in perturbative quantum field theories. In this work, we consider the light front quantum electrodynamics in (3+1) dimensions and evaluate the photon polarization tensor at one loop for both zero and finite temperatures. In the first case, we apply the dimensional regularization method to extract the finite contribution and find the transverse structure for the amplitude in terms of the light front coordinates. The result agrees with one-loop covariant calculation. For the thermal corrections, we generalize the hard thermal loop approximation to the light front and calculate the dominant temperature contribution to the polarization tensor, consistent with the Ward identity. In both zero as well as finite temperature calculations, we use the oblique light front coordinates. (author)

  3. Generalized reduced rank latent factor regression for high dimensional tensor fields, and neuroimaging-genetic applications.

    Science.gov (United States)

    Tao, Chenyang; Nichols, Thomas E; Hua, Xue; Ching, Christopher R K; Rolls, Edmund T; Thompson, Paul M; Feng, Jianfeng

    2017-01-01

    We propose a generalized reduced rank latent factor regression model (GRRLF) for the analysis of tensor field responses and high dimensional covariates. The model is motivated by the need from imaging-genetic studies to identify genetic variants that are associated with brain imaging phenotypes, often in the form of high dimensional tensor fields. GRRLF identifies from the structure in the data the effective dimensionality of the data, and then jointly performs dimension reduction of the covariates, dynamic identification of latent factors, and nonparametric estimation of both covariate and latent response fields. After accounting for the latent and covariate effects, GRLLF performs a nonparametric test on the remaining factor of interest. GRRLF provides a better factorization of the signals compared with common solutions, and is less susceptible to overfitting because it exploits the effective dimensionality. The generality and the flexibility of GRRLF also allow various statistical models to be handled in a unified framework and solutions can be efficiently computed. Within the field of neuroimaging, it improves the sensitivity for weak signals and is a promising alternative to existing approaches. The operation of the framework is demonstrated with both synthetic datasets and a real-world neuroimaging example in which the effects of a set of genes on the structure of the brain at the voxel level were measured, and the results compared favorably with those from existing approaches. Copyright © 2016. Published by Elsevier Inc.

  4. Supersymmetry for gauged double field theory and generalised Scherk–Schwarz reductions

    International Nuclear Information System (INIS)

    Berman, David S.; Lee, Kanghoon

    2014-01-01

    Previous constructions of supersymmetry for double field theory have relied on the so-called strong constraint. In this paper, the strong constraint is relaxed and the theory is shown to possess supersymmetry once the generalised Scherk–Schwarz reduction is imposed. The equivalence between the generalised Scherk–Schwarz reduced theory and the gauged double field theory is then examined in detail for the supersymmetric theory. As a biproduct we write the generalised Killing spinor equations for the supersymmetric double field theory

  5. Gauge fields with respect to d = (3+1) in the Kaluza-Klein theories and in the spin-charge-family theory

    Energy Technology Data Exchange (ETDEWEB)

    Lukman, Dragan; Mankoc Borstnik, Norma Susana [University of Ljubljana, Department of Physics, FMF, Ljubljana (Slovenia)

    2017-04-15

    It is shown that in the spin-charge-family theory (Mankoc Borstnik in arXiv:1607.01618v2, 2016, Phys Rev D 91:065004. arxiv:1409.7791, 2015, J Mod Phys 6:2244. doi:10.4236/jmp.2015.615230. arXiv: 1409.4981, 2015, J Mod Phys 4:823. doi:10.4236/jmp.2013.46113. arxiv:1312.1542, 2013, arxiv:1409.4981, 2014) as well as in all the Kaluza-Klein like theories (Blagojevic in Gravitation and gauge symmetries, IoP Publishing, Bristol, 2002, An introduction to Kaluza-Klein theories, World Scientific, Singapore, 1983), vielbeins and spin connections manifest in d = (3+1) space equivalent vector gauge fields, when space with d ≥ 5 has a large enough symmetry. The authors demonstrate this equivalence in spaces with the symmetry of the metric tensor in the space out of d = (3+1)-g{sup στ} = η{sup στ} f{sup 2} - for any scalar function f of the coordinates x{sup σ}, where x{sup σ} denotes the coordinates of space out of d = (3+1). Also the connection between vielbeins and scalar gauge fields in d = (3+1) (offering the explanation for the Higgs scalar) is discussed. (orig.)

  6. The invariant polarisation-tensor field for deuterons in storage rings and the Bloch equation for the polarisation-tensor density

    International Nuclear Information System (INIS)

    Barber, D.P.

    2015-10-01

    I extend and update earlier work, summarised in an earlier paper (D.P. Barber, M. Voigt, AIP Conference Proceedings 1149 (28)), whereby the invariant polarisation-tensor field (ITF) for deuterons in storage rings was introduced to complement the invariant spin field (ISF). Taken together, the ITF and the ISF provide a definition of the equilibrium spin density-matrix field which, in turn, offers a clean framework for describing equilibrium spin-1 ensembles in storage rings. I show how to construct the ITF by stroboscopic averaging, I give examples, I discuss adiabatic invariance and I introduce a formalism for describing the effect of noise and damping.

  7. Energy-momentum-tensor in quantumelectrodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Schott, T

    1974-01-01

    This work deals with the operator properties of the energy-momentum-tensor (ET) in the framework of quantum electrodynamics. The principles of construction of the ET are discussed for quantized fields in the Schwinger variation principle. Dealing with the conserved quantities for quantized fields operator problems are coming up in the Coulomb gauge because Dirac- and Maxwellfield do not commute completely. Further on contemporary commutators of the ET components are investigated mutually. Finally non-canonical methods are developed.

  8. Relations between correlation functions in gauge field theory

    International Nuclear Information System (INIS)

    Simonov, Yu. A.; Shevchenko, V. I.

    1997-01-01

    Exact relations between vacuum correlations of non-Abelian field strengths are obtained. With the aid of exterior differentiation, the invariant parts of a given correlation function are expressed in terms of higher order correlation functions. The corollaries of these relations for the behavior of nonperturbative correlation functions at small and large distances are deduced

  9. Microscopic 57 Fe electric-field-gradient and anisotropic mean-squared-displacement tensors: ferrous chloride tetrahydrate

    International Nuclear Information System (INIS)

    Bull, James N.; Fitchett, Christopher M.; Tennant, W. Craighead

    2010-01-01

    This paper reports the determination of the electric-field-gradient and mean-squared-displacement tensors in 57 Fe symmetry-related sites of 1-bar Laue class in monoclinic FeCl 2 .4H 2 O at room temperature by single-crystal Mössbauer spectroscopy. Contrary to all previous work, the mean-squared-displacement matrix (tensor), , is not constrained to be isotropic resulting in the determination of physically meaningful estimates of microscopic (local) electric-field gradient (efg) and tensors. As a consequence of anisotropy in the tensor the absorber recoilless fractions are also anisotropic. As expected of a low-symmetry site, Laue class 1-bar in this case, no two principal axes of the efg and tensors are coaxial, within the combined errors in the two. Further, no principal direction of the efg tensor seems related to bond directions in the unit cell. Within error, and in agreement with an earlier study of sodium nitroprusside, it appears that the tensor principal directions lie close to the crystallographic axes suggesting that they are determined by long wavelength (phonon) vibrations in the crystal rather than by approximate local symmetry about the 57 Fe nucleus. Concurrent with the Mössbauer measurements, we determined as part of a new X-ray structural determination, precise atomic displacement parameters (ADPs) leading to an alternative determination of the matrix (tensor). The average of the eigenvalues of the Mössbauer-determined exceeds that of the average of the X-ray-determined eigenvalues by a factor of around 2.2. Assuming isotropic absorber recoilless fractions leads to substantially the same (macroscopic) efg tensor as had been determined in earlier work. Taking 1/3 x the trace of the anisotropic absorber recoilless fractions leads to an isotropic value of 0.304 in good agreement with earlier single crystal studies where isotropy was assumed.

  10. Tensor categories and endomorphisms of von Neumann algebras with applications to quantum field theory

    CERN Document Server

    Bischoff, Marcel; Longo, Roberto; Rehren, Karl-Henning

    2015-01-01

    C* tensor categories are a point of contact where Operator Algebras and Quantum Field Theory meet. They are the underlying unifying concept for homomorphisms of (properly infinite) von Neumann algebras and representations of quantum observables. The present introductory text reviews the basic notions and their cross-relations in different contexts. The focus is on Q-systems that serve as complete invariants, both for subfactors and for extensions of quantum field theory models. It proceeds with various operations on Q-systems (several decompositions, the mirror Q-system, braided product, centre and full centre of Q-systems) some of which are defined only in the presence of a braiding. The last chapter gives a brief exposition of the relevance of the mathematical structures presented in the main body for applications in Quantum Field Theory (in particular two-dimensional Conformal Field Theory, also with boundaries or defects).

  11. Energy-momentum tensor in thermal strong-field QED with unstable vacuum

    Energy Technology Data Exchange (ETDEWEB)

    Gavrilov, S P [Department of General and Experimental Physics, Herzen State Pedagogical University of Russia, Moyka emb. 48, 191186 St Petersburg (Russian Federation); Gitman, D M [Instituto de Fisica, Universidade de Sao Paulo, CP 66318, CEP 05315-970 Sao Paulo, SP (Brazil)], E-mail: gavrilovsergeyp@yahoo.com, E-mail: gitman@dfn.if.usp.br

    2008-04-25

    The mean value of the one-loop energy-momentum tensor in thermal QED with an electric-like background that creates particles from vacuum is calculated. The problem is essentially different from calculations of effective actions (similar to the action of Heisenberg-Euler) in backgrounds that respect the stability of vacuum. The role of a constant electric background in the violation of both the stability of vacuum and the thermal character of particle distribution is investigated. Restrictions on the electric field and the duration over which one can neglect the back-reaction of created particles are established.

  12. Energy-momentum tensor in thermal strong-field QED with unstable vacuum

    International Nuclear Information System (INIS)

    Gavrilov, S P; Gitman, D M

    2008-01-01

    The mean value of the one-loop energy-momentum tensor in thermal QED with an electric-like background that creates particles from vacuum is calculated. The problem is essentially different from calculations of effective actions (similar to the action of Heisenberg-Euler) in backgrounds that respect the stability of vacuum. The role of a constant electric background in the violation of both the stability of vacuum and the thermal character of particle distribution is investigated. Restrictions on the electric field and the duration over which one can neglect the back-reaction of created particles are established

  13. Berry phase of primordial scalar and tensor perturbations in single-field inflationary models

    Science.gov (United States)

    Balajany, Hamideh; Mehrafarin, Mohammad

    2018-06-01

    In the framework of the single-field slow-roll inflation, we derive the Hamiltonian of the linear primordial scalar and tensor perturbations in the form of time-dependent harmonic oscillator Hamiltonians. We find the invariant operators of the resulting Hamiltonians and use their eigenstates to calculate the adiabatic Berry phase for sub-horizon modes in terms of the Lewis-Riesenfeld phase. We conclude by discussing the discrepancy in the results of Pal et al. (2013) [21] for these Berry phases, which is resolved to yield agreement with our results.

  14. Tunable axial gauge fields in engineered Weyl semimetals: semiclassical analysis and optical lattice implementations

    Science.gov (United States)

    Roy, Sthitadhi; Kolodrubetz, Michael; Goldman, Nathan; Grushin, Adolfo G.

    2018-04-01

    In this work, we describe a toolbox to realize and probe synthetic axial gauge fields in engineered Weyl semimetals. These synthetic electromagnetic fields, which are sensitive to the chirality associated with Weyl nodes, emerge due to spatially and temporally dependent shifts of the corresponding Weyl momenta. First, we introduce two realistic models, inspired by recent cold-atom developments, which are particularly suitable for the exploration of these synthetic axial gauge fields. Second, we describe how to realize and measure the effects of such axial fields through center-of-mass observables, based on semiclassical equations of motion and exact numerical simulations. In particular, we suggest realistic protocols to reveal an axial Hall response due to the axial electric field \

  15. On the principle of gauge invariance in the field theory with curved momentum space

    International Nuclear Information System (INIS)

    Mir-Kasimov, R.M.

    1990-11-01

    The gauge transformations consistent with the hypothesis of the curved momentum space are considered. In this case the components of the electromagnetic field are not commuting. The finite-difference analogue of the D'Alambert equation is derived. (author). 5 refs

  16. Static, self-dual, finite action SU(3) gauge fields in the de Sitter space

    International Nuclear Information System (INIS)

    Chakrabarti, A.; Comtet, A.; Viswanathan, K.S.; Simon Fraser Univ., Burnaby, British Columbia

    1980-01-01

    Static, self-dual, finite action SU(3) gauge fields are constructed on the euclidean section of the positive curvature de Sitter metric with periodic time. Their relation to known time dependent flat space solutions is pointed out. Their significances and possible applications are indicated. (orig.)

  17. Construction of quantized gauge fields: continuum limit of the Abelian Higgs model in two dimensions

    International Nuclear Information System (INIS)

    Seiler, E.

    1981-01-01

    The author proves the existence of the continuum limit of the two-dimensional Higgs model for two cases: External gauge fields that are Hoelder continuous and may be non-Abelian, and the fully quantized Abelian model. In the latter case all Wightman axioms are verified except clustering. Important ingredients are a universal diamagnetic bound and correlation inequalities. (Auth.)

  18. Some physical solutions of Yang's equations for SU (2) gauge fields ...

    Indian Academy of Sciences (India)

    Some previously obtained physical solutions [1–3] of Yang's equations for (2) gauge fields [4], Charap's equations for pion dynamics [5,6] and their combination as proposed by Chakraborty and Chanda [1] have been presented. They represent different physical characteristics, e.g. spreading wave with solitary profile ...

  19. 'Symmetry dictates interaction'. For the jubilee of the non-abelian gauge fields

    International Nuclear Information System (INIS)

    Li Huazhong

    2004-01-01

    The article is written for the Jubilee, 50 years after the birth of non-abelian gauge field theory which was proposed by C.N. yang and R. Mills in 1954. The main ideas initiated in the paper and great influences are briefly outlined

  20. Restoration of symmetry by temperature effect under influence of external electro magnetic field in gauge theory

    International Nuclear Information System (INIS)

    Aquino, V.M. de.

    1987-01-01

    We have analysed, within a semi classical approach, the influence of external electromagnetic field on phase transitions in gauge theories. The critical temperature was calculated for an Abelian case, scalar electrodynamics, and for an non Abelian case, the Weinberg Salam model. (author)

  1. Geometrical phases from global gauge invariance of nonlinear classical field theories

    International Nuclear Information System (INIS)

    Garrison, J.C.; Chiao, R.Y.

    1988-01-01

    We show that the geometrical phases recently discovered in quantum mechanics also occur naturally in the theory of any classical complex multicomponent field satisfying nonlinear equations derived from a Lagrangean with is invariant under gauge transformations of the first kind. Some examples are the paraxial wave equation for nonlinear optics, and Ginzburg-Landau equations for complex order parameters in condensed-matter physics

  2. N=2, 4 supersymmetric gauge field theory in two-time physics

    International Nuclear Information System (INIS)

    Bars, Itzhak; Kuo, Y.-C.

    2009-01-01

    In the context of two-time physics in 4+2 dimensions we construct the most general N=2, 4 supersymmetric Yang-Mills gauge theories for any gauge group G. This builds on our previous work for N=1 supersymmetry (SUSY). The action, the conserved SUSY currents, and the SU(N) covariant SUSY transformation laws are presented for both N=2 and N=4. When the equations of motion are used the SUSY transformations close to the supergroup SU(2,2|N) with N=1, 2, 4. The SU(2,2)=SO(4,2) subsymmetry is realized linearly on 4+2 dimensional flat spacetime. All fields, including vectors and spinors, are in 4+2 dimensions. The extra gauge symmetries in 2T field theory, together with the kinematic constraints that follow from the action, remove all the ghosts to give a unitary theory. By choosing gauges and solving the kinematic equations, the 2T field theory in 4+2 flat spacetime can be reduced to various shadows in various 3+1 dimensional (generally curved) spacetimes. These shadows are related to each other by dualities. The conformal shadows of our theories in flat 3+1 dimensions coincide with the well known counterpart N=1, 2, 4 supersymmetric massless renormalizable field theories in 3+1 dimensions. It is expected that our more symmetric new structures in 4+2 spacetime may be useful for nonperturbative or exact solutions of these theories.

  3. Bowen-York tensors

    International Nuclear Information System (INIS)

    Beig, Robert; Krammer, Werner

    2004-01-01

    For a conformally flat 3-space, we derive a family of linear second-order partial differential operators which sends vectors into trace-free, symmetric 2-tensors. These maps, which are parametrized by conformal Killing vectors on the 3-space, are such that the divergence of the resulting tensor field depends only on the divergence of the original vector field. In particular, these maps send source-free electric fields into TT tensors. Moreover, if the original vector field is the Coulomb field on R 3 {0}, the resulting tensor fields on R 3 {0} are nothing but the family of TT tensors originally written by Bowen and York

  4. Loop calculations for the non-commutative U*(1) gauge field model with oscillator term

    International Nuclear Information System (INIS)

    Blaschke, Daniel N.; Grosse, Harald; Kronberger, Erwin; Schweda, Manfred; Wohlgenannt, Michael

    2010-01-01

    Motivated by the success of the non-commutative scalar Grosse-Wulkenhaar model, a non-commutative U * (1) gauge field theory including an oscillator-like term in the action has been put forward in (Blaschke et al. in Europhys. Lett. 79:61002, 2007). The aim of the current work is to analyze whether that action can lead to a fully renormalizable gauge model on non-commutative Euclidean space. In a first step, explicit one-loop graph computations are hence presented, and their results as well as necessary modifications of the action are successively discussed. (orig.)

  5. A study of fermions coupled to gauge and gravitational fields on a cylinder

    Energy Technology Data Exchange (ETDEWEB)

    Lano, R.P. [Iowa Univ., Iowa City, IA (United States). Dept. of Physics and Astronomy; Rodgers, V.G.J. [Iowa Univ., Iowa City, IA (United States). Dept. of Physics and Astronomy

    1995-03-06

    Fermions on a cylinder coupled to background gravitation and gauge fields are examined by studying the geometric action associated with the symmetries of such a system. We are able to show that the gauge coupling constant is constrained to a value of 1/N where N is an integer. Furthermore, in direct analogy with a Yang-Mills theory a new gravitational theory is introduced which couples to the fermions by promoting the coadjoint vector of the diffeomorphism sector to a dynamical variable. The classical dynamics of this theory are examined by displaying its symplectic structure and showing that it is equivalent to a one-dimensional system. ((orig.)).

  6. Tensors for physics

    CERN Document Server

    Hess, Siegfried

    2015-01-01

    This book presents the science of tensors in a didactic way. The various types and ranks of tensors and the physical basis is presented. Cartesian Tensors are needed for the description of directional phenomena in many branches of physics and for the characterization the anisotropy of material properties. The first sections of the book provide an introduction to the vector and tensor algebra and analysis, with applications to physics,  at undergraduate level. Second rank tensors, in particular their symmetries, are discussed in detail. Differentiation and integration of fields, including generalizations of the Stokes law and the Gauss theorem, are treated. The physics relevant for the applications in mechanics, quantum mechanics, electrodynamics and hydrodynamics is presented. The second part of the book is devoted to  tensors of any rank, at graduate level.  Special topics are irreducible, i.e. symmetric traceless tensors, isotropic tensors, multipole potential tensors, spin tensors, integration and spin-...

  7. Equation of Motion of a Mass Point in Gravitational Field and Classical Tests of Gauge Theory of Gravity

    International Nuclear Information System (INIS)

    Wu Ning; Zhang Dahua

    2007-01-01

    A systematic method is developed to study the classical motion of a mass point in gravitational gauge field. First, by using Mathematica, a spherical symmetric solution of the field equation of gravitational gauge field is obtained, which is just the traditional Schwarzschild solution. Combining the principle of gauge covariance and Newton's second law of motion, the equation of motion of a mass point in gravitational field is deduced. Based on the spherical symmetric solution of the field equation and the equation of motion of a mass point in gravitational field, we can discuss classical tests of gauge theory of gravity, including the deflection of light by the sun, the precession of the perihelia of the orbits of the inner planets and the time delay of radar echoes passing the sun. It is found that the theoretical predictions of these classical tests given by gauge theory of gravity are completely the same as those given by general relativity.

  8. Tensor algebra over Hilbert space: Field theory in classical phase space

    International Nuclear Information System (INIS)

    Matos Neto, A.; Vianna, J.D.M.

    1984-01-01

    It is shown using tensor algebras, namely Symmetric and Grassmann algebras over Hilbert Space that it is possible to introduce field operators, associated to the Liouville equation of classical statistical mechanics, which are characterized by commutation (for Symmetric) and anticommutation (for Grassmann) rules. The procedure here presented shows by construction that many-particle classical systems admit an algebraic structure similar to that of quantum field theory. It is considered explicitly the case of n-particle systems interacting with an external potential. A new derivation of Schoenberg's result about the equivalence between his field theory in classical phase space and the usual classical statistical mechanics is obtained as a consequence of the algebraic structure of the theory as introduced by our method. (Author) [pt

  9. The stress energy tensor of a locally supersymmetric quantum field on a curved spacetime

    International Nuclear Information System (INIS)

    Koehler, M.

    1995-04-01

    For an analogon of the free Wess-Zumino model on Ricci flat spacetimes, the relation between a conserved 'supercurrent' and the point-separated improved energy momentum tensor is investigated and a similar relation as on Minkowski space is established. The expectation value of the latter in any globally Hadamard product state is found to be a priori finite in the coincidence limit if the theory is massive. On arbitrary globally hyperbolic spacetimes the 'supercurrent' is shown to be a well defined operator valued distribution on the GNS Hilbertspace of any globally Hadamard product state. Viewed as a new field, all n-point distributions exist, giving a new example for a Wightman field on that manifold. Moreover, it is shown that this field satisfies a new wave front set spectrum condition in a nontrivial way. (orig.)

  10. Dynamical mechanism of symmetry breaking and particle mass generation in gauge field theories

    International Nuclear Information System (INIS)

    Miranskij, V.A.; Fomin, P.I.

    1985-01-01

    The dynamics of the spotaneous symmetry breaking and the particle mass generation in gauge theories with no fundamental scalar fields is considered. The emphasis is on the consideration of the symmetry breaking mechanism connected with the dynamics of the supercritical Coulomb-like forces caused by the gauge boson exchange between fermions. This mechanism is applied to different gauge theories, in particular, to the description of the spontaneous chira symmetry breaking in quantum chromodynamics. The mass relations for pseudoscalar meson nonet are obtained and it is shown that this mechanism resuls in the dynamical realisation of the hypothesis of the partial conservation of the axial-vector currents. The qualitative description of scalar mesons is given. The nature of the ultraviolet divergencies in quantum electrodynamics (QED) is investigated from the viewpoint of the dynamics of the fermion mass generation. The mechanism of the appearance of the additional (in comparison with perturbation theory) ultraviolet divergencies in QED with large bare coupling constant is indicated. The physical phenomenon underlying this mechanism is identified as the field theory analogue of the quantum mechanical ''fall into the centre'' (collapse) phenomenon. The similr phenomenon is shown to take place in some two-dimensional quantum field models. The dynamics of the bifermion condensates formation in tumblin gauge theories is briefly discussed

  11. Restoration of the covariant gauge α in the initial field of gravity in de Sitter spacetime

    Energy Technology Data Exchange (ETDEWEB)

    Cheong, Lee Yen; Yan, Chew Xiao [Department of Fundamental and Applied Sciences, Universiti Teknologi Petronas, Bandar Seri Iskandar, Tronoh 31750, Perak (Malaysia)

    2014-03-05

    The gravitational field generated by a mass term and the initial surface through covariant retarded Green's function for linearized gravity in de Sitter spacetime was studied recently [4, 5] with the covariant gauges set to β = 2/3 and α = 5/3. In this paper we extend the work to restore the gauge parameter α in the field coming from the initial data using the method of shifting the parameter. The α terms in the initial field cancels exactly with the one coming from the source term. Consequently, the correct field configuration, with two equal mass points moving in its geodesic, one located at the North pole and another one located at the South pole, is reproduced in the whole manifold of de Sitter spacetime.

  12. On the Motion of Matter in the Geometrical Gauge Field Theory

    CERN Document Server

    Konopleva, N P

    2005-01-01

    In the geometrical gauge field theory, the motion equations of matter (elementary particles) are connected with the field equations. In the talk, the problems arising from this connection are discussed. For the first time, such problems arose in Einstein's General Relativity. Einstein hoped that solution of these problems will allow explanation of elementary particles nature without making use of quantum mechanics. But, as it turned out, the situation is more difficult. Here the corresponding problems are formulated for the connection of equations of particle motion and field equations in the geometrical gauge field theory. It is shown that appearance of the problems under discussion is an inevitable effect of passage to relativism and local symmetries.

  13. Pure gauge configurations and solutions to fermionic superstring field theory equations of motion

    International Nuclear Information System (INIS)

    Aref'eva, I Ya; Gorbachev, R V; Medvedev, P B

    2009-01-01

    Recent results on solutions to the equation of motion of the cubic fermionic string field theory and an equivalence of nonpolynomial and cubic string field theory are discussed. To have the possibility of dealing with both GSO(+) and GSO(-) sectors in the uniform way, a matrix formulation for the NS fermionic SFT is used. In constructions of analytical solutions to open-string field theories truncated pure gauge configurations parametrized by wedge states play an essential role. The matrix form of this parametrization for NS fermionic SFT is presented. Using the cubic open superstring field theory as an example we demonstrate explicitly that for the large parameter of the perturbation expansion these truncated pure gauge configurations give divergent contributions to the equations of motion on the subspace of the wedge states. The perturbation expansion is corrected by adding extra terms that are just those necessary for the equation of motion contracted with the solution itself to be satisfied.

  14. Bjorken-Johnson-Low technique and perturbation study on chiral anomaly in abelian coset pure gauge field theory

    International Nuclear Information System (INIS)

    Jing Sicong; Ruan Jie; AH. Dept. of Modern Physics)

    1990-01-01

    The perturbation theory in coset pure gauge field theory is studied for the first time. By using the Bjorken-johnson-Low technique and calculating the Schwinger term in related commutators, the anomalous Ward identity in Abelian coset pure gauge field theory is derived, which is consistent with the non-perutrbative calculation

  15. On a gauge theory of the self-dual field and its quantization

    International Nuclear Information System (INIS)

    Srivastava, P.P.

    1990-01-01

    A gauge theory of self-dual fields is constructed by adding a Wess-Zumino term to the recently studied formulation based on a second-order scalar field lagrangian carrying with it an auxiliary vector field to take care of the self-duality constraint in a linear fashion. The two versions are quantized using the BRST formulation following the BFV procedure. No violation of microcausality occurs and the action of the ordinary scalar field may not be written as the sum of the actions of the self- and anti-self-dual fields. (orig.)

  16. Superconformal quantum field theories in string. Gauge theory dualities

    Energy Technology Data Exchange (ETDEWEB)

    Wiegandt, Konstantin

    2012-08-14

    In this thesis aspects of superconformal field theories that are of interest in the so-called AdS/CFT correspondence are investigated. The AdS/CFT correspondence states a duality between string theories living on Anti-de Sitter space and superconformal quantum field theories in Minkowski space. In the context of the AdS/CFT correspondence the so-called Wilson loop/amplitude duality was discovered, stating the equality of the finite parts of n-gluon MHV amplitudes and n-sided lightlike polygonal Wilson loops in N=4 supersymmetric Yang-Mills (SYM) theory. It is the subject of the first part of this thesis to investigate the Wilson loop side of a possible similar duality in N=6 superconformal Chern-Simons matter (ABJM) theory. The main result is, that the expectation value of n-sided lightlike polygonal Wilson loops vanishes at one-loop order and at two-loop order is identical in its functional form to the Wilson loop in N=4 SYM theory at one-loop order. Furthermore, an anomalous conformal Ward identity for Wilson loops in Chern-Simons theory is derived. Related developments and symmetries of amplitudes and correlators in ABJM theory are discussed as well. In the second part of this thesis we calculate three-point functions of two protected operators and one twist-two operator with arbitrary even spin j in N=4 SYM theory. In order to carry out the calculations, the indices of the spin j operator are projected to the light-cone and the correlator is evaluated in a soft-limit where the momentum coming in at the spin j operator becomes zero. This limit largely simplifies the perturbative calculation, since all three-point diagrams effectively reduce to two-point diagrams and the dependence on the one-loop mixing matrix drops out completely. The result is in agreement with the analysis of the operator product expansion of four-point functions of half-BPS operators by Dolan and Osborn in 2004.

  17. Superconformal quantum field theories in string. Gauge theory dualities

    International Nuclear Information System (INIS)

    Wiegandt, Konstantin

    2012-01-01

    In this thesis aspects of superconformal field theories that are of interest in the so-called AdS/CFT correspondence are investigated. The AdS/CFT correspondence states a duality between string theories living on Anti-de Sitter space and superconformal quantum field theories in Minkowski space. In the context of the AdS/CFT correspondence the so-called Wilson loop/amplitude duality was discovered, stating the equality of the finite parts of n-gluon MHV amplitudes and n-sided lightlike polygonal Wilson loops in N=4 supersymmetric Yang-Mills (SYM) theory. It is the subject of the first part of this thesis to investigate the Wilson loop side of a possible similar duality in N=6 superconformal Chern-Simons matter (ABJM) theory. The main result is, that the expectation value of n-sided lightlike polygonal Wilson loops vanishes at one-loop order and at two-loop order is identical in its functional form to the Wilson loop in N=4 SYM theory at one-loop order. Furthermore, an anomalous conformal Ward identity for Wilson loops in Chern-Simons theory is derived. Related developments and symmetries of amplitudes and correlators in ABJM theory are discussed as well. In the second part of this thesis we calculate three-point functions of two protected operators and one twist-two operator with arbitrary even spin j in N=4 SYM theory. In order to carry out the calculations, the indices of the spin j operator are projected to the light-cone and the correlator is evaluated in a soft-limit where the momentum coming in at the spin j operator becomes zero. This limit largely simplifies the perturbative calculation, since all three-point diagrams effectively reduce to two-point diagrams and the dependence on the one-loop mixing matrix drops out completely. The result is in agreement with the analysis of the operator product expansion of four-point functions of half-BPS operators by Dolan and Osborn in 2004.

  18. Mean field theory for non-abelian gauge theories and fluid dynamics. A brief progress report

    International Nuclear Information System (INIS)

    Wadia, Spenta R.

    2009-01-01

    We review the long standing problem of 'mean field theory' for non-abelian gauge theories. As a consequence of the AdS/CFT correspondence, in the large N limit, at strong coupling, and high temperatures and density, the 'mean field theory' is described by the Navier-Stokes equations of fluid dynamics. We also discuss and present results on the non-conformal fluid dynamics of the D1 brane in 1+1 dim. (author)

  19. Pair production in an electric field in a time-dependent gauge

    International Nuclear Information System (INIS)

    Barut, A.O.; Duru, I.H.

    1989-07-01

    A new nonperturbative method of calculation of the pair production in a constant electric field is presented in which the propagator is evaluated entirely by path-integration in a time-dependent potential. This gauge and the path integration correctly define all the normalizations. As a by-product we get also the Unruh formula since the constant electric field provides an accelerated frame. (author). 11 refs

  20. Valley-polarized quantum transport generated by gauge fields in graphene

    DEFF Research Database (Denmark)

    Settnes, Mikkel; Garcia, Jose H; Roche, Stephan

    2017-01-01

    We report on the possibility to simultaneously generate in graphene a bulk valley-polarized dissipative transport and a quantum valley Hall effect by combining strain-induced gauge fields and real magnetic fields. Such unique phenomenon results from a ‘resonance/anti-resonance’ effect driven by t...... Kubo transport methods combined with a valley projection scheme to access valley-dependent conductivities and show that the results are robust against disorder....

  1. Gauge anomaly with vector and axial-vector fields in 6D curved space

    Science.gov (United States)

    Yajima, Satoshi; Eguchi, Kohei; Fukuda, Makoto; Oka, Tomonori

    2018-03-01

    Imposing the conservation equation of the vector current for a fermion of spin 1/2 at the quantum level, a gauge anomaly for the fermion coupling with non-Abelian vector and axial-vector fields in 6D curved space is expressed in tensorial form. The anomaly consists of terms that resemble the chiral U(1) anomaly and the commutator terms that disappear if the axial-vector field is Abelian.

  2. Spin and pseudospin symmetric Dirac particles in the field of Tietz—Hua potential including Coulomb tensor interaction

    International Nuclear Information System (INIS)

    Ikhdair, Sameer M.; Hamzavi, Majid

    2013-01-01

    Approximate analytical solutions of the Dirac equation for Tietz—Hua (TH) potential including Coulomb-like tensor (CLT) potential with arbitrary spin—orbit quantum number κ are obtained within the Pekeris approximation scheme to deal with the spin—orbit coupling terms κ(κ ± 1)r −2 . Under the exact spin and pseudospin symmetric limitation, bound state energy eigenvalues and associated unnormalized two-component wave functions of the Dirac particle in the field of both attractive and repulsive TH potential with tensor potential are found using the parametric Nikiforov—Uvarov (NU) method. The cases of the Morse oscillator with tensor potential, the generalized Morse oscillator with tensor potential, and the non-relativistic limits have been investigated. (general)

  3. Introduction to gauge theories

    International Nuclear Information System (INIS)

    Wit, B. de

    1983-01-01

    In these lectures we present the key ingredients of theories with local gauge invariance. We introduce gauge invariance as a starting point for the construction of a certain class of field theories, both for abelian and nonabelian gauge groups. General implications of gauge invariance are discussed, and we outline in detail how gauge fields can acquire masses in a spontaneous fashion. (orig./HSI)

  4. Emergent Gauge Fields and Their Nonperturbative Effects in Correlated Electrons

    Science.gov (United States)

    Kim, Ki-Seok; Tanaka, Akihiro

    dynamics of topological excitations is again seen to be crucial in classifying topologically nontrivial gapped systems. We point to some hidden links between several effective field theories with topological terms, starting with one dimensional physics, and subsequently finding natural generalizations to higher dimensions.

  5. Gravity/Fluid Correspondence and Its Application on Bulk Gravity with U(1) Gauge Field

    International Nuclear Information System (INIS)

    Hu, Ya-Peng; Zhang, Jian-Hui

    2014-01-01

    As the long wavelength limit of the AdS/CFT correspondence, the gravity/fluid correspondence has been shown to be a useful tool for extracting properties of the fluid on the boundary dual to the gravity in the bulk. In this paper, after briefly reviewing the algorithm of gravity/fluid correspondence, we discuss the results of its application on bulk gravity with a U(1) gauge field. In the presence of a U(1) gauge field, the dual fluid possesses more interesting properties such as its charge current. Furthermore, an external field A_μ"e"x"t could affect the charge current, and the U(1) Chern-Simons term also induces extra structures to the dual current giving anomalous transport coefficients.

  6. Valley-polarized quantum transport generated by gauge fields in graphene

    Science.gov (United States)

    Settnes, Mikkel; Garcia, Jose H.; Roche, Stephan

    2017-09-01

    We report on the possibility to simultaneously generate in graphene a bulk valley-polarized dissipative transport and a quantum valley Hall effect by combining strain-induced gauge fields and real magnetic fields. Such unique phenomenon results from a ‘resonance/anti-resonance’ effect driven by the superposition/cancellation of superimposed gauge fields which differently affect time reversal symmetry. The onset of a valley-polarized Hall current concomitant to a dissipative valley-polarized current flow in the opposite valley is revealed by a {{e}2}/h Hall conductivity plateau. We employ efficient linear scaling Kubo transport methods combined with a valley projection scheme to access valley-dependent conductivities and show that the results are robust against disorder.

  7. Study of the characteristics of crust stress field in East China by inversion of stress tensor

    International Nuclear Information System (INIS)

    Huilan, Z.; Rugang, D.

    1991-12-01

    This paper combines the search procedure with the optimization procedure to inverse the average stress tensor, and applies this method to study the crustal stress field using data of the solution of P wave first motion. By dealing with the data of Haicheng, Tangshan, Xingtai, Anyang, Liyang, Taiwan, Fujian and Guangdong areas, we obtain the characteristics of crust stress field of East China. The directions of the principal pressure stress always possess a small dip angle, but the azimuths vary from NEE (in north part of East China) to SEE (in the south part). This frame probably is related to the push-extrusive effects of the northwestern Pacific plate from NEE and the Philippine plate from SEE. (author). 5 refs, 8 figs, 4 tabs

  8. Confining gauge theories and holographic entanglement entropy with a magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Dudal, David [KU Leuven Campus Kortrijk - KULAK, Department of Physics,Etienne Sabbelaan 51 bus 7800, Kortrijk, 8500 (Belgium); Ghent University, Department of Physics and Astronomy,Krijgslaan 281-S9, Gent, 9000 (Belgium); Mahapatra, Subhash [KU Leuven Campus Kortrijk - KULAK, Department of Physics,Etienne Sabbelaan 51 bus 7800, Kortrijk, 8500 (Belgium)

    2017-04-06

    We consider the soft wall model for a heuristic holographical modelling of a confining gauge theory and discuss how the introduction of a (constant) magnetic field influences the (de)confinement phase structure. We use the entanglement entropy as a diagnostic tool in terms of the length of an entangling strip geometry. Due to the anisotropy introduced by the magnetic field, we find that the results depend on the orientation of the strip relative to the field. This allows to identify a richer, anisotropic, interplay between confinement and a magnetic field than possibly can be extracted from a more standard order parameter as, for example, the Polyakov loop expectation value.

  9. Stress-free states of continuum dislocation fields : Rotations, grain boundaries, and the Nye dislocation density tensor

    NARCIS (Netherlands)

    Limkumnerd, Surachate; Sethna, James P.

    We derive general relations between grain boundaries, rotational deformations, and stress-free states for the mesoscale continuum Nye dislocation density tensor. Dislocations generally are associated with long-range stress fields. We provide the general form for dislocation density fields whose

  10. Elastic fields, dipole tensors, and interaction between self-interstitial atom defects in bcc transition metals

    Science.gov (United States)

    Dudarev, S. L.; Ma, Pui-Wai

    2018-03-01

    Density functional theory (DFT) calculations show that self-interstitial atom (SIA) defects in nonmagnetic body-centered-cubic (bcc) metals adopt strongly anisotropic configurations, elongated in the direction [S. Han et al., Phys. Rev. B 66, 220101 (2002), 10.1103/PhysRevB.66.220101; D. Nguyen-Manh et al., Phys. Rev. B 73, 020101 (2006), 10.1103/PhysRevB.73.020101; P. M. Derlet et al., Phys. Rev. B 76, 054107 (2007), 10.1103/PhysRevB.76.054107; S. L. Dudarev, Annu. Rev. Mater. Res. 43, 35 (2013), 10.1146/annurev-matsci-071312-121626]. Elastic distortions, associated with such anisotropic atomic structures, appear similar to distortions around small prismatic dislocation loops, although the extent of this similarity has never been quantified. We derive analytical formulas for the dipole tensors of SIA defects, which show that, in addition to the prismatic dislocation looplike character, the elastic field of a SIA defect also has a significant isotropic dilatation component. Using empirical potentials and DFT calculations, we parametrize dipole tensors of defects for all the nonmagnetic bcc transition metals. This enables a quantitative evaluation of the energy of elastic interaction between the defects, which also shows that in a periodic three-dimensional simple cubic arrangement of crowdions, long-range elastic interactions between a defect and all its images favor a orientation of the defect.

  11. Linear Invariant Tensor Interpolation Applied to Cardiac Diffusion Tensor MRI

    Science.gov (United States)

    Gahm, Jin Kyu; Wisniewski, Nicholas; Kindlmann, Gordon; Kung, Geoffrey L.; Klug, William S.; Garfinkel, Alan; Ennis, Daniel B.

    2015-01-01

    Purpose Various methods exist for interpolating diffusion tensor fields, but none of them linearly interpolate tensor shape attributes. Linear interpolation is expected not to introduce spurious changes in tensor shape. Methods Herein we define a new linear invariant (LI) tensor interpolation method that linearly interpolates components of tensor shape (tensor invariants) and recapitulates the interpolated tensor from the linearly interpolated tensor invariants and the eigenvectors of a linearly interpolated tensor. The LI tensor interpolation method is compared to the Euclidean (EU), affine-invariant Riemannian (AI), log-Euclidean (LE) and geodesic-loxodrome (GL) interpolation methods using both a synthetic tensor field and three experimentally measured cardiac DT-MRI datasets. Results EU, AI, and LE introduce significant microstructural bias, which can be avoided through the use of GL or LI. Conclusion GL introduces the least microstructural bias, but LI tensor interpolation performs very similarly and at substantially reduced computational cost. PMID:23286085

  12. gauge fields

    Indian Academy of Sciences (India)

    Here it has been found that the real form of Yang's self-dual equations [2,3] passes the Painlevé test for integrability in the sense of Weiss et al [4] and admit truncation of series leading to non-trivial exact solutions obtained previously and auto-Backlund transformation between two pairs of these solutions (see for example.

  13. Spin dynamics under local gauge fields in chiral spin-orbit coupling systems

    International Nuclear Information System (INIS)

    Tan, S.G.; Jalil, M.B.A.; Fujita, T.; Liu, X.J.

    2011-01-01

    Research highlights: → We derive a modified LLG equation in magnetic systems with spin-orbit coupling (SOC). → Our results are applied to magnetic multilayers, and DMS and magnetic Rashba systems. → SOC mediated magnetization switching is predicted in rare earth metals (large SOC). → The magnetization trajectory and frequency can be modulated by applied voltage. → This facilitates potential application as tunable microwave oscillators. - Abstract: We present a theoretical description of local spin dynamics in magnetic systems with a chiral spin texture and finite spin-orbit coupling (SOC). Spin precession about the relativistic effective magnetic field in a SOC system gives rise to a non-Abelian SU(2) gauge field reminiscent of the Yang-Mills field. In addition, the adiabatic relaxation of electron spin along the local spin yields an U(1) x U(1) topological gauge (Berry) field. We derive the corresponding equation of motion i.e. modified Landau-Lifshitz-Gilbert (LLG) equation, for the local spin under the influence of these effects. Focusing on the SU(2) gauge, we obtain the spin torque magnitude, and the amplitude and frequency of spin oscillations in this system. Our theoretical estimates indicate significant spin torque and oscillations in systems with large spin-orbit coupling, which may be utilized in technological applications such as current-induced magnetization-switching and tunable microwave oscillators.

  14. Gauge field theoretic solution of a uniformly moving screw dislocation and admissibility of supersonic speeds

    International Nuclear Information System (INIS)

    Sharma, P.; Zhang, X.

    2006-01-01

    The failure of classical elasticity to address dislocation behavior spatially close to its core and (in Lorentz-type fashion) near the speed of sound is well known. In gauge field theory of defects, the latter are not postulated a priori in an ad hoc fashion rather defects such as dislocations arise naturally as a consequence of broken translational symmetry exhibiting solutions that are physically meaningful (e.g., removal of divergence of stress and the natural emergence of a core making redundant the artificial cut-off radius). In the present work we present the gauge field theoretic solution to the problem of a uniformly moving screw dislocation. Apart from the formal derivations, we show that stress divergence at the core of the dislocation is removed at all time and (consistent with atomistic simulations), supersonic states are found to be admissible

  15. Localizing gauge fields on a topological Abelian string and the Coulomb law

    International Nuclear Information System (INIS)

    Torrealba S, Rafael S.

    2010-01-01

    The confinement of electromagnetic field is studied in axial symmetrical, warped, six-dimensional brane world, using a recently proposed topological Abelian string-vortex solution as background. It was found, that the massless gauge field fluctuations follow four-dimensional Maxwell equations in the Lorenz gauge. The massless zero mode is localized when the thickness of the string vortex is less than 5β/4πe 2 v 2 and there are no other localized massless modes. There is also an infinite of nonlocalized massive Fourier modes, that follow four-dimensional Proca equations with a continuous spectrum. To compute the corrections to the Coulomb potential, a radial cutoff was introduced, in order to achieve a discrete mass spectrum. As a main result, a (R o /βR 2 ) correction was found for the four-dimensional effective Coulomb law; the result is in correspondence with the observed behavior of the Coulomb potential at today's measurable distances.

  16. Chiral symmetry breaking and nonperturbative scale anomaly in gauge field theories

    International Nuclear Information System (INIS)

    Miranskij, V.A.; Gusynin, V.P.

    1987-01-01

    The nonperturbative dynamics of chiral and scale symmetry breaking in asymtotically free and non-asymptotically free (with an ultraviolet stable fixed point) vector-like gauge theories is investigated. In the two-loop approximation analytical expressions for the chiral and gluon condensates are obtained. The hypothesis about a soft behaviour at small distances of composite operators in non-asymptotically free gauge theories with a fixed point is put forward and substantiated. It is shown that in these theories the form of the scale anomaly depends on the type of the phase in coupling constant to which it relates. A new dilaton effective lagrangian for glueball and chiral fields is suggested. The mass relation for the single scalar fermion-antifermion bound state is obtained. The important ingredient of this approach is a large (d≅ 2) dynamical dimension of composite chiral fields. The application of this approach to QCD and technicolour models is discussed

  17. Double gauge invariance and covariantly-constant vector fields in Weyl geometry

    Science.gov (United States)

    Kassandrov, Vladimir V.; Rizcallah, Joseph A.

    2014-08-01

    The wave equation and equations of covariantly-constant vector fields (CCVF) in spaces with Weyl nonmetricity turn out to possess, in addition to the canonical conformal-gauge, a gauge invariance of another type. On a Minkowski metric background, the CCVF system alone allows us to pin down the Weyl 4-metricity vector, identified herein with the electromagnetic potential. The fundamental solution is given by the ordinary Lienard-Wiechert field, in particular, by the Coulomb distribution for a charge at rest. Unlike the latter, however, the magnitude of charge is necessarily unity, "elementary", and charges of opposite signs correspond to retarded and advanced potentials respectively, thus establishing a direct connection between the particle/antiparticle asymmetry and the "arrow of time".

  18. Noncommutative o*(N) and usp*(2N) algebras and the corresponding gauge field theories

    International Nuclear Information System (INIS)

    Bars, I.; Sheikh-Jabbari, M.M.; Vasiliev, M.A.

    2001-03-01

    The extension of the noncommutative u * (N) Lie algebra to noncommutative orthogonal and symplectic Lie algebras is studied. Using an anti-automorphism of the star-matrix algebra, we show that the u * (N) can consistently be restricted to o * (N) and usp * (N) algebras that have new mathematical structures. We give explicit fundamental matrix representations of these algebras, through which the formulation for the corresponding noncommutative gauge field theories are obtained. In addition, we present a D-brane configuration with an orientifold which realizes geometrically our algebraic construction, thus embedding the new noncommutative gauge theories in superstring theory in the presence of a constant background magnetic field. Some algebraic generalizations that may have applications in other areas of physics are also discussed. (author)

  19. On a stochastic process associated to non-abelian gauge fields

    International Nuclear Information System (INIS)

    Vilela Mendes, R.

    1989-01-01

    A stochastic process is constructed from a ground state measure that generalizes to non-abelian fields the ground state of abelian (free) gauge fields without fermions. Using a latticized version one shows how the process leads to a well-defined quantum theory in the Schroedinger representation. An analysis of the qualitative behaviour of the theory seems to imply a quasi-free behaviour at short distances and a maximally disordered field strength configuration for the low-momentum component of the ground state. Scaling relations for the mass gap are inferred from the theory of small random perturbations of dynamical systems. (orig.)

  20. Strongly correlated states of a small cold-atom cloud from geometric gauge fields

    International Nuclear Information System (INIS)

    Julia-Diaz, B.; Dagnino, D.; Barberan, N.; Guenter, K. J.; Dalibard, J.; Grass, T.; Lewenstein, M.

    2011-01-01

    Using exact diagonalization for a small system of cold bosonic atoms, we analyze the emergence of strongly correlated states in the presence of an artificial magnetic field. This gauge field is generated by a laser beam that couples two internal atomic states, and it is related to Berry's geometrical phase that emerges when an atom follows adiabatically one of the two eigenstates of the atom-laser coupling. Our approach allows us to go beyond the adiabatic approximation, and to characterize the generalized Laughlin wave functions that appear in the strong magnetic-field limit.

  1. Strongly correlated states of a small cold-atom cloud from geometric gauge fields

    Energy Technology Data Exchange (ETDEWEB)

    Julia-Diaz, B. [Dept. ECM, Facultat de Fisica, U. Barcelona, E-08028 Barcelona (Spain); ICFO-Institut de Ciencies Fotoniques, Parc Mediterrani de la Tecnologia, E-08860 Barcelona (Spain); Dagnino, D.; Barberan, N. [Dept. ECM, Facultat de Fisica, U. Barcelona, E-08028 Barcelona (Spain); Guenter, K. J.; Dalibard, J. [Laboratoire Kastler Brossel, CNRS, UPMC, Ecole Normale Superieure, 24 rue Lhomond, F-75005 Paris (France); Grass, T. [ICFO-Institut de Ciencies Fotoniques, Parc Mediterrani de la Tecnologia, E-08860 Barcelona (Spain); Lewenstein, M. [ICFO-Institut de Ciencies Fotoniques, Parc Mediterrani de la Tecnologia, E-08860 Barcelona (Spain); ICREA-Institucio Catalana de Recerca i Estudis Avancats, E-08010 Barcelona (Spain)

    2011-11-15

    Using exact diagonalization for a small system of cold bosonic atoms, we analyze the emergence of strongly correlated states in the presence of an artificial magnetic field. This gauge field is generated by a laser beam that couples two internal atomic states, and it is related to Berry's geometrical phase that emerges when an atom follows adiabatically one of the two eigenstates of the atom-laser coupling. Our approach allows us to go beyond the adiabatic approximation, and to characterize the generalized Laughlin wave functions that appear in the strong magnetic-field limit.

  2. Constant external fields in gauge theory and the spin 0, 1/2, 1 path integrals

    International Nuclear Information System (INIS)

    Reuter, M.; Schmidt, M.G.

    1996-10-01

    We investigate the usefulness of the ''string-inspired technique'' for gauge theory calculations in a constant external field background. Our approach is based on Strassler's worldline path integral approach to the Bern-Kosower formalism, and on the construction of worldline (super-) Green's functions incorporating external fields as well as internal propagators. The worldline path integral representation of the gluon loop is reexamined in detail. We calculate the two-loop effective actions induced for a constant external field by a scalar and spinor loop, and the corresponding one-loop effective action in the gluon loop case. (orig.)

  3. An introduction of gauge field by the Lie-isotopic lifting of the Hilbert space

    International Nuclear Information System (INIS)

    Nishioka, M.

    1984-01-01

    It is introduced the gauge field by the Lie-isotopic lifting of the Hilbert space. Our method is different from other's in that the commutator between the isotropic element and the generators of the Lie algebra does not vanish in our case, but vanishes in other cases. Our method uses the Lie-isotopic lifting of the Hilbert space, but others do not use it

  4. Nilpotent BRST charge without auxillary B fields in quantum gauge theories

    International Nuclear Information System (INIS)

    Tsai, E.C.

    1991-01-01

    This paper introduces a modified BRST transformation for non-Abelian gauge theories. In this transformation, there is no need to introduce auxiliary B fields, yet the generatior Q for the modified transformation is nilpotent and commutes with the Hamiltonian. The Lagrangian is no longer invariant under Q, but the quantum theory which is defined by the Hamiltonian is still symmetric with respect to the transformation generated by Q

  5. On the algebraic structure of self-dual gauge fields and sigma models

    International Nuclear Information System (INIS)

    Bais, F.A.; Sasaki, R.

    1983-01-01

    An extensive and detailed analysis of self-dual gauge fields, in particular with axial symmetry, is presented, culminating in a purely algebraic procedure to generate solutions. The method which is particularly suited for the construction of multimonopole solutions for a theory with arbitrary G, is also applicable to a wide class of non-linear sigma models. The relevant symmetries as well as the associated linear problems which underly the exact solubility of the problem, are constructed and discussed in detail. (orig.)

  6. Interaction potentials for multiquark states from instantons and other background gauge field configurations

    International Nuclear Information System (INIS)

    Warner, R.C.; Joshi, G.C.

    1979-01-01

    A simple rule is presented for calculating the contributions to the interaction potentials between constituent particles for a family of multiquark states, due to the presence of a semi-classical gauge field configuration which exists in a single SU(2) subgroup of colour SU(3). In multiquark states beyond the baryon many-body potential terms are found. The static (Wilson loop) limit is sufficient to elucidate the dependence of the potential on the colour structure of the multiquark state

  7. Strong coupling gauge theories and effective field theories. Proceedings of the 2002 international workshop

    International Nuclear Information System (INIS)

    Harada, Masayasu; Kikukawa, Yoshio; Yamawaki, Koichi

    2003-01-01

    This issue presents the important recent progress in both theoretical and phenomenological issues of strong coupling gauge theories, with/without supersymmetry and extra dimensions, etc. Emphasis in a placed on dynamical symmetry breaking with large anomalous dimensions governed by the dynamics near the nontrivial fixed point. Also presented are recent developments of the corresponding effective field theories. The 43 of the presented papers are indexed individually. (J.P.N)

  8. Spontaneous symmetry breaking, and strings defects in hypercomplex gauge field theories

    Energy Technology Data Exchange (ETDEWEB)

    Cartas-Fuentevilla, R. [Universidad Autonoma de Puebla, Instituto de Fisica, Puebla, Pue. (Mexico); Meza-Aldama, O. [Universidad Autonoma de Puebla, Facultad de Ciencias Fisico-Matematicas, Puebla, Pue. (Mexico)

    2016-02-15

    Inspired by the appearance of split-complex structures in the dimensional reduction of string theory, and in the theories emerging as byproducts, we study the hypercomplex formulation of Abelian gauge field theories by incorporating a new complex unit to the usual complex one. The hypercomplex version of the traditional Mexican hat potential associated with the U(1) gauge field theory, corresponds to a hybrid potential with two real components, and with U(1) x SO(1,1) as symmetry group. Each component corresponds to a deformation of the hat potential, with the appearance of a new degenerate vacuum. Hypercomplex electrodynamics will show novel properties, such as spontaneous symmetry breaking scenarios with running masses for the vectorial and scalar Higgs fields, and such as Aharonov-Bohm type strings defects as exact solutions; these topological defects may be detected only by quantum interference of charged particles through gauge invariant loop integrals. In a particular limit, the hyperbolic electrodynamics does not admit topological defects associated with continuous symmetries. (orig.)

  9. Tensor-based morphometry with mappings parameterized by stationary velocity fields in Alzheimer's disease neuroimaging initiative.

    Science.gov (United States)

    Bossa, Matías Nicolás; Zacur, Ernesto; Olmos, Salvador

    2009-01-01

    Tensor-based morphometry (TBM) is an analysis technique where anatomical information is characterized by means of the spatial transformations between a customized template and observed images. Therefore, accurate inter-subject non-rigid registration is an essential prerrequisite. Further statistical analysis of the spatial transformations is used to highlight some useful information, such as local statistical differences among populations. With the new advent of recent and powerful non-rigid registration algorithms based on the large deformation paradigm, TBM is being increasingly used. In this work we evaluate the statistical power of TBM using stationary velocity field diffeomorphic registration in a large population of subjects from Alzheimer's Disease Neuroimaging Initiative project. The proposed methodology provided atrophy maps with very detailed anatomical resolution and with a high significance compared with results published recently on the same data set.

  10. Magnetizability and rotational g tensors for density fitted local second-order Møller-Plesset perturbation theory using gauge-including atomic orbitals

    International Nuclear Information System (INIS)

    Loibl, Stefan; Schütz, Martin

    2014-01-01

    In this paper, we present theory and implementation of an efficient program for calculating magnetizabilities and rotational g tensors of closed-shell molecules at the level of local second-order Møller-Plesset perturbation theory (MP2) using London orbitals. Density fitting is employed to factorize the electron repulsion integrals with ordinary Gaussians as fitting functions. The presented program for the calculation of magnetizabilities and rotational g tensors is based on a previous implementation of NMR shielding tensors reported by S. Loibl and M. Schütz [J. Chem. Phys. 137, 084107 (2012)]. Extensive test calculations show (i) that the errors introduced by density fitting are negligible, and (ii) that the errors of the local approximation are still rather small, although larger than for nuclear magnetic resonance (NMR) shielding tensors. Electron correlation effects for magnetizabilities are tiny for most of the molecules considered here. MP2 appears to overestimate the correlation contribution of magnetizabilities such that it does not constitute an improvement over Hartree-Fock (when comparing to higher-order methods like CCSD(T)). For rotational g tensors the situation is different and MP2 provides a significant improvement in accuracy over Hartree-Fock. The computational performance of the new program was tested for two extended systems, the larger comprising about 2200 basis functions. It turns out that a magnetizability (or rotational g tensor) calculation takes about 1.5 times longer than a corresponding NMR shielding tensor calculation

  11. Gauge theories

    International Nuclear Information System (INIS)

    Kenyon, I.R.

    1986-01-01

    Modern theories of the interactions between fundamental particles are all gauge theories. In the case of gravitation, application of this principle to space-time leads to Einstein's theory of general relativity. All the other interactions involve the application of the gauge principle to internal spaces. Electromagnetism serves to introduce the idea of a gauge field, in this case the electromagnetic field. The next example, the strong force, shows unique features at long and short range which have their origin in the self-coupling of the gauge fields. Finally the unification of the description of the superficially dissimilar electromagnetic and weak nuclear forces completes the picture of successes of the gauge principle. (author)

  12. Conversed, gauge-covariant colour charge in Su(n)QCD

    International Nuclear Information System (INIS)

    Selikhov, A.V.

    1988-01-01

    The definition of the integral of the group tensor and the gauge-covariant differential with respect to a distant point are given in the work. A conserved covariant charge dependence on family of paths has been contracted with the help of these notions. It has been shown that the same family of paths fixes a gauge in which the covariant and noncovariant conserved currents coicide. The gauge is characterized by representation of the vector potential via field strength tensor. The possibility of connecting the choice of the family of paths with the measurement procedure is discussed. 13 refs.; 2 figs

  13. Self-dual gauge theories

    International Nuclear Information System (INIS)

    Zet, G.

    2002-01-01

    The self-duality equations are important in gauge theories because they show the connection between gauge models with internal symmetry groups and gauge theory of gravity. They are differential equations of the first order and it is easier to investigate the solutions for different particular configurations of the gauge fields and of space-times.One of the most important property of the self-duality equations is that they imply the Yang-Mills field equations. In this paper we will prove this property for the general case of a gauge theory with compact Lie group of symmetry over a 4-dimensional space-time manifold. It is important to remark that there are 3m independent self-duality equations (of the first order) while the number of Yang-Mills equations is equal to 4m, where m is the dimension of the gauge group. Both of them have 4m unknown functions which are the gauge potentials A μ a (x), a = 1, 2, ....,m; μ = 0, 1, 2, 3. But, we have, in addition, m gauge conditions for A μ a (x), (for example Coulomb, Lorentz or axial gauge) which together with the selfduality equation constitute a system of 4m equations. The Bianchi identities for the self-dual stress tensor F μν a coincide with the Yang-Mills equations and do not imply therefore supplementary conditions. We use the axial gauge in order to obtain the self duality equations for a SU(2) gauge theory over a curved space-time. The compatibility between self-duality and Yang-Mills equations is studied and some classes of solutions are obtained. In fact, we will write the Einstein-Yang-Mills equations and we will analyse only the Yang-Mills sector. The Einstein equations can not be obtained of course from self-duality. They should be obtained if we would consider a gauge theory having P x SU(2) as symmetry group, where P is the Poincare group. More generally, a gauge theory of N-extended supersymmetry can be developed by imposing the self-duality condition. (author)

  14. Continuity equations for bound electromagnetic field and the electromagnetic energy-momentum tensor

    International Nuclear Information System (INIS)

    Kholmetskii, A L; Missevitch, O V; Yarman, T

    2011-01-01

    We analyze the application of the Poynting theorem to the bound (velocity-dependent) electromagnetic (EM) field and show that an often-used arbitrary elimination of the term of self-interaction in the product j·E (where j is the current density and E the electric field) represents, in general, an illegitimate operation, which leads to incorrect physical consequences. We propose correct ways of eliminating the terms of self-interaction from the Poynting theorem to transform it into the form that is convenient for problems with bound EM field, which yield the continuity equations for the proper EM energy density, the interaction part of EM energy density and the total EM energy density of bound fields, respectively. These equations indicate the incompleteness of the common EM energy-momentum tensor, and in our analysis, we find a missed term in its structure, which makes its trace non-vanished. Some implications of these results are discussed, in particular, in view of the notion of EM mass of charged particles.

  15. Continuity equations for bound electromagnetic field and the electromagnetic energy-momentum tensor

    Energy Technology Data Exchange (ETDEWEB)

    Kholmetskii, A L [Department of Physics, Belarusian State University, 4 Nezavisimosti Avenue, 220030 Minsk (Belarus); Missevitch, O V [Institute for Nuclear Problems, Belarusian State University, 11 Bobruiskaya Street, 220030 Minsk (Belarus); Yarman, T, E-mail: khol123@yahoo.com [Department of Engineering, Okan University, Akfirat, Istanbul, Turkey and Savronik, Eskisehir (Turkey)

    2011-05-01

    We analyze the application of the Poynting theorem to the bound (velocity-dependent) electromagnetic (EM) field and show that an often-used arbitrary elimination of the term of self-interaction in the product j{center_dot}E (where j is the current density and E the electric field) represents, in general, an illegitimate operation, which leads to incorrect physical consequences. We propose correct ways of eliminating the terms of self-interaction from the Poynting theorem to transform it into the form that is convenient for problems with bound EM field, which yield the continuity equations for the proper EM energy density, the interaction part of EM energy density and the total EM energy density of bound fields, respectively. These equations indicate the incompleteness of the common EM energy-momentum tensor, and in our analysis, we find a missed term in its structure, which makes its trace non-vanished. Some implications of these results are discussed, in particular, in view of the notion of EM mass of charged particles.

  16. Dissecting CFT Correlators and String Amplitudes. Conformal Blocks and On-Shell Recursion for General Tensor Fields

    International Nuclear Information System (INIS)

    Hansen, Tobias

    2015-07-01

    This thesis covers two main topics: the tensorial structure of quantum field theory correlators in general spacetime dimensions and a method for computing string theory scattering amplitudes directly in target space. In the first part tensor structures in generic bosonic CFT correlators and scattering amplitudes are studied. To this end arbitrary irreducible tensor representations of SO(d) (traceless mixed-symmetry tensors) are encoded in group invariant polynomials, by contracting with sets of commuting and anticommuting polarization vectors which implement the index symmetries of the tensors. The tensor structures appearing in CFT d correlators can then be inferred by studying these polynomials in a d + 2 dimensional embedding space. It is shown with an example how these correlators can be used to compute general conformal blocks describing the exchange of mixed-symmetry tensors in four-point functions, which are crucial for advancing the conformal bootstrap program to correlators of operators with spin. Bosonic string theory lends itself as an ideal example for applying the same methods to scattering amplitudes, due to its particle spectrum of arbitrary mixed-symmetry tensors. This allows in principle the definition of on-shell recursion relations for string theory amplitudes. A further chapter introduces a different target space definition of string scattering amplitudes. As in the case of on-shell recursion relations, the amplitudes are expressed in terms of their residues via BCFW shifts. The new idea here is that the residues are determined by use of the monodromy relations for open string theory, avoiding the infinite sums over the spectrum arising in on-shell recursion relations. Several checks of the method are presented, including a derivation of the Koba-Nielsen amplitude in the bosonic string. It is argued that this method provides a target space definition of the complete S-matrix of string theory at tree-level in a at background in terms of a small

  17. Quantum field theory III. Gauge theory. A bridge between mathematicians and physicists

    International Nuclear Information System (INIS)

    Zeidler, Eberhard

    2011-01-01

    In this third volume of his modern introduction to quantum field theory, Eberhard Zeidler examines the mathematical and physical aspects of gauge theory as a principle tool for describing the four fundamental forces which act in the universe: gravitative, electromagnetic, weak interaction and strong interaction. Volume III concentrates on the classical aspects of gauge theory, describing the four fundamental forces by the curvature of appropriate fiber bundles. This must be supplemented by the crucial, but elusive quantization procedure. The book is arranged in four sections, devoted to realizing the universal principle force equals curvature: Part I: The Euclidean Manifold as a Paradigm Part II: Ariadne's Thread in Gauge Theory Part III: Einstein's Theory of Special Relativity Part IV: Ariadne's Thread in Cohomology For students of mathematics the book is designed to demonstrate that detailed knowledge of the physical background helps to reveal interesting interrelationships among diverse mathematical topics. Physics students will be exposed to a fairly advanced mathematics, beyond the level covered in the typical physics curriculum. Quantum Field Theory builds a bridge between mathematicians and physicists, based on challenging questions about the fundamental forces in the universe (macrocosmos), and in the world of elementary particles (microcosmos). (orig.)

  18. Quantum field theory III. Gauge theory. A bridge between mathematicians and physicists

    Energy Technology Data Exchange (ETDEWEB)

    Zeidler, Eberhard [Max Planck Institute for Mathematics in the Sciences, Leipzig (Germany)

    2011-07-01

    In this third volume of his modern introduction to quantum field theory, Eberhard Zeidler examines the mathematical and physical aspects of gauge theory as a principle tool for describing the four fundamental forces which act in the universe: gravitative, electromagnetic, weak interaction and strong interaction. Volume III concentrates on the classical aspects of gauge theory, describing the four fundamental forces by the curvature of appropriate fiber bundles. This must be supplemented by the crucial, but elusive quantization procedure. The book is arranged in four sections, devoted to realizing the universal principle force equals curvature: Part I: The Euclidean Manifold as a Paradigm Part II: Ariadne's Thread in Gauge Theory Part III: Einstein's Theory of Special Relativity Part IV: Ariadne's Thread in Cohomology For students of mathematics the book is designed to demonstrate that detailed knowledge of the physical background helps to reveal interesting interrelationships among diverse mathematical topics. Physics students will be exposed to a fairly advanced mathematics, beyond the level covered in the typical physics curriculum. Quantum Field Theory builds a bridge between mathematicians and physicists, based on challenging questions about the fundamental forces in the universe (macrocosmos), and in the world of elementary particles (microcosmos). (orig.)

  19. Compactly supported linearised observables in single-field inflation

    Energy Technology Data Exchange (ETDEWEB)

    Fröob, Markus B.; Higuchi, Atsushi [Department of Mathematics, University of York, Heslington, York, YO10 5DD (United Kingdom); Hack, Thomas-Paul, E-mail: mbf503@york.ac.uk, E-mail: thomas-paul.hack@itp.uni-leipzig.de, E-mail: atsushi.higuchi@york.ac.uk [Institut für Theoretische Physik, Universität Leipzig, Brüderstraße 16, 04103 Leipzig (Germany)

    2017-07-01

    We investigate the gauge-invariant observables constructed by smearing the graviton and inflaton fields by compactly supported tensors at linear order in general single-field inflation. These observables correspond to gauge-invariant quantities that can be measured locally. In particular, we show that these observables are equivalent to (smeared) local gauge-invariant observables such as the linearised Weyl tensor, which have better infrared properties than the graviton and inflaton fields. Special cases include the equivalence between the compactly supported gauge-invariant graviton observable and the smeared linearised Weyl tensor in Minkowski and de Sitter spaces. Our results indicate that the infrared divergences in the tensor and scalar perturbations in single-field inflation have the same status as in de Sitter space and are both a gauge artefact, in a certain technical sense, at tree level.

  20. Discrete finite nilpotent Lie analogs: New models for unified gauge field theory

    International Nuclear Information System (INIS)

    Kornacker, K.

    1978-01-01

    To each finite dimensional real Lie algebra with integer structure constants there corresponds a countable family of discrete finite nilpotent Lie analogs. Each finite Lie analog maps exponentially onto a finite unipotent group G, and is isomorphic to the Lie algebra of G. Reformulation of quantum field theory in discrete finite form, utilizing nilpotent Lie analogs, should elminate all divergence problems even though some non-Abelian gauge symmetry may not be spontaneously broken. Preliminary results in the new finite representation theory indicate that a natural hierarchy of spontaneously broken symmetries can arise from a single unbroken non-Abelian gauge symmetry, and suggest the possibility of a new unified group theoretic interpretation for hadron colors and flavors

  1. Effective field theory analysis on μ problem in low-scale gauge mediation

    International Nuclear Information System (INIS)

    Zheng Sibo

    2012-01-01

    Supersymmetric models based on the scenario of gauge mediation often suffer from the well-known μ problem. In this paper, we reconsider this problem in low-scale gauge mediation in terms of effective field theory analysis. In this paradigm, all high energy input soft mass can be expressed via loop expansions. If the corrections coming from messenger thresholds are small, as we assume in this letter, then all RG evaluations can be taken as linearly approximation for low-scale supersymmetric breaking. Due to these observations, the parameter space can be systematically classified and studied after constraints coming from electro-weak symmetry breaking are imposed. We find that some old proposals in the literature are reproduced, and two new classes are uncovered. We refer to a microscopic model, where the specific relations among coefficients in one of the new classes are well motivated. Also, we discuss some primary phenomenologies.

  2. Supersymmetric gauge theories, quantization of M{sub flat}, and conformal field theory

    Energy Technology Data Exchange (ETDEWEB)

    Teschner, J.; Vartanov, G.S.

    2013-02-15

    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.

  3. Gauging hidden symmetries in two dimensions

    International Nuclear Information System (INIS)

    Samtleben, Henning; Weidner, Martin

    2007-01-01

    We initiate the systematic construction of gauged matter-coupled supergravity theories in two dimensions. Subgroups of the affine global symmetry group of toroidally compactified supergravity can be gauged by coupling vector fields with minimal couplings and a particular topological term. The gauge groups typically include hidden symmetries that are not among the target-space isometries of the ungauged theory. The gaugings constructed in this paper are described group-theoretically in terms of a constant embedding tensor subject to a number of constraints which parametrizes the different theories and entirely encodes the gauged Lagrangian. The prime example is the bosonic sector of the maximally supersymmetric theory whose ungauged version admits an affine e 9 global symmetry algebra. The various parameters (related to higher-dimensional p-form fluxes, geometric and non-geometric fluxes, etc.) which characterize the possible gaugings, combine into an embedding tensor transforming in the basic representation of e 9 . This yields an infinite-dimensional class of maximally supersymmetric theories in two dimensions. We work out and discuss several examples of higher-dimensional origin which can be systematically analyzed using the different gradings of e 9

  4. The tensor calculus and matter coupling of the alternative minimal auxiliary field formulation of N = 1 supergravity

    International Nuclear Information System (INIS)

    Sohnius, M.; West, P.

    1982-01-01

    The tensor calculus for the new alternative minimal auxiliary field formulation of N = 1 supergravity is given. It is used to construct the couplings of this formulation of supergravity to matter. These couplings are found to be different, in several respects to those of the old minimal formulation of N = 1 supergravity. (orig.)

  5. Electromagnetic Field Theory in (N+1)-Space-Time : AModern Time-Domain Tensor/Array Introduction

    NARCIS (Netherlands)

    De Hoop, A.T.

    2012-01-01

    In this paper, a modern time-domain introduction is presented for electromagnetic field theory in (N+1)-spacetime. It uses a consistent tensor/array notation that accommodates the description of electromagnetic phenomena in N-dimensional space (plus time), a requirement that turns up in present-day

  6. Can Effective Field Theory of inflation generate large tensor-to-scalar ratio within Randall–Sundrum single braneworld?

    International Nuclear Information System (INIS)

    Choudhury, Sayantan

    2015-01-01

    In this paper my prime objective is to explain the generation of large tensor-to-scalar ratio from the single field sub-Planckian inflationary paradigm within Randall–Sundrum (RS) single braneworld scenario in a model independent fashion. By explicit computation I have shown that the effective field theory prescription of brane inflation within RS single brane setup is consistent with sub-Planckian excursion of the inflaton field, which will further generate large value of tensor-to-scalar ratio, provided the energy density for inflaton degrees of freedom is high enough compared to the brane tension in high energy regime. Finally, I have mentioned the stringent theoretical constraint on positive brane tension, cut-off of the quantum gravity scale and bulk cosmological constant to get sub-Planckian field excursion along with large tensor-to-scalar ratio as recently observed by BICEP2 or at least generates the tensor-to-scalar ratio consistent with the upper bound of Planck (2013 and 2015) data and Planck+BICEP2+Keck Array joint constraint

  7. Hydrogen bond interactions in sulfamerazine: DFT study of the O-17, N-14, and H-2 electric field gradient tensors

    International Nuclear Information System (INIS)

    Aghazadeh, Mustafa; Mirzaei, Mahmoud

    2008-01-01

    Hydrogen bond (HB) interactions are studied in the real crystalline structure of sulfamerazine by density functional theory (DFT) calculations of the electric field gradient (EFG) tensors at the sites of O-17, N-14, and H-2 nuclei. One-molecule (single) and four-molecule (cluster) models of sulfamerazine are created by available crystal coordinates and the EFG tensors are calculated in both models to indicate the influence of HB interactions on the tensors. Directly relate to the experiments, the calculated EFG tensors are converted to the experimentally measurable nuclear quadrupole resonance (NQR) parameters, quadrupole coupling constant (qcc) and asymmetry parameter (η Q ). The evaluated NQR parameters reveal that due to contribution of the target molecule to N-H...N and N-H...O types of HB interactions, the EFG tensors at the sites of various nuclei are influenced from single model to the target molecule in cluster. Additionally, O2, N4, and H2 nuclei of the target molecule are significantly influenced by HB interactions, consequently, they have the major contributions to HB interactions in cluster model of sulfamerazine. The calculations are performed employing B3LYP method and 6-311++G** basis set using GAUSSIAN 98 suite of program

  8. TensorLy: Tensor Learning in Python

    OpenAIRE

    Kossaifi, Jean; Panagakis, Yannis; Pantic, Maja

    2016-01-01

    Tensors are higher-order extensions of matrices. While matrix methods form the cornerstone of machine learning and data analysis, tensor methods have been gaining increasing traction. However, software support for tensor operations is not on the same footing. In order to bridge this gap, we have developed \\emph{TensorLy}, a high-level API for tensor methods and deep tensorized neural networks in Python. TensorLy aims to follow the same standards adopted by the main projects of the Python scie...

  9. Renormalization of the Nambu-Jona Lasinio model and spontaneously broken Abelian Gauge model without fundamental scalar fields

    International Nuclear Information System (INIS)

    Snyderman, N.J.

    1976-01-01

    The Schwinger-Dyson equation for the Nambu-Jona Lasinio model is solved systematically subject to the constraint of spontaneously broken chiral symmetry. The solution to this equation generates interactions not explicitly present in the original Lagrangian, and the original 4-fermion interaction is not present in the solution. The theory creates bound-states with respect to which a perturbation theory consistent with the chiral symmetry is set up. The analysis suggests that this theory is renormalizable in the sense that all divergences can be grouped into a few arbitrary parameters. The renormalized propagators of this model are shown to be identical to those of a new solution to the sigma-model in which the bare 4-field coupling lambda 0 is chosen to be twice the π-fermion coupling g 0 . Also considered is spontaneously broken abelian gauge model without fundamental scalar fields by coupling an axial vector gauge field to the N ambu-Jona Lasinio model. It is shown how the Goldstone consequence of spontaneous symmetry breaking is avoided in the radiation gauge, and verify the Guralnik, Hagen, and Kibble theorem that under these conditions the global charge conservation is lost even though there is still local current conservation. This is contrasted with the Lorentz gauge situation. This also demonstrated the way the various noncovariant components of the massive gauge field combine in a gauge invariant scattering amplitude to propagate covariantly as a massive spin-1 particle, and this is compared with the Lorentz gauge calculation. F inally, a new model of interacting massless fermions is introduced, based on the models of Nambu and Jona Lasinio, and the Bjorken, which spontaneously breaks both chiral symmetry and Lorentz invariance. The content of this model is the same as that of the gauge model without fundamental scalar fields, but without fundamental gauge fields as well

  10. An Ar threesome: Matrix models, 2d conformal field theories, and 4dN=2 gauge theories

    International Nuclear Information System (INIS)

    Schiappa, Ricardo; Wyllard, Niclas

    2010-01-01

    We explore the connections between three classes of theories: A r quiver matrix models, d=2 conformal A r Toda field theories, and d=4N=2 supersymmetric conformal A r quiver gauge theories. In particular, we analyze the quiver matrix models recently introduced by Dijkgraaf and Vafa (unpublished) and make detailed comparisons with the corresponding quantities in the Toda field theories and the N=2 quiver gauge theories. We also make a speculative proposal for how the matrix models should be modified in order for them to reproduce the instanton partition functions in quiver gauge theories in five dimensions.

  11. Homogeneous collapsing star: Tensor and vector harmonics for matter and field asymmetries

    International Nuclear Information System (INIS)

    Gerlach, U.H.; Sengupta, U.K.

    1978-01-01

    For the space-time of the interior of a homogeneous collapsing star complete sets of orthogonal vector and tensor harmonics are presented. Their relationship to the set of vector and tensor harmonics for a generic spherically symmetric space-time is exhibited

  12. Solar System constraints on massless scalar-tensor gravity with positive coupling constant upon cosmological evolution of the scalar field

    Science.gov (United States)

    Anderson, David; Yunes, Nicolás

    2017-09-01

    Scalar-tensor theories of gravity modify general relativity by introducing a scalar field that couples nonminimally to the metric tensor, while satisfying the weak-equivalence principle. These theories are interesting because they have the potential to simultaneously suppress modifications to Einstein's theory on Solar System scales, while introducing large deviations in the strong field of neutron stars. Scalar-tensor theories can be classified through the choice of conformal factor, a scalar that regulates the coupling between matter and the metric in the Einstein frame. The class defined by a Gaussian conformal factor with a negative exponent has been studied the most because it leads to spontaneous scalarization (i.e. the sudden activation of the scalar field in neutron stars), which consequently leads to large deviations from general relativity in the strong field. This class, however, has recently been shown to be in conflict with Solar System observations when accounting for the cosmological evolution of the scalar field. We here study whether this remains the case when the exponent of the conformal factor is positive, as well as in another class of theories defined by a hyperbolic conformal factor. We find that in both of these scalar-tensor theories, Solar System tests are passed only in a very small subset of coupling parameter space, for a large set of initial conditions compatible with big bang nucleosynthesis. However, while we find that it is possible for neutron stars to scalarize, one must carefully select the coupling parameter to do so, and even then, the scalar charge is typically 2 orders of magnitude smaller than in the negative-exponent case. Our study suggests that future work on scalar-tensor gravity, for example in the context of tests of general relativity with gravitational waves from neutron star binaries, should be carried out within the positive coupling parameter class.

  13. Spinor matter fields in SL(2,C) gauge theories of gravity: Lagrangian and Hamiltonian approaches

    Science.gov (United States)

    Antonowicz, Marek; Szczyrba, Wiktor

    1985-06-01

    We consider the SL(2,C)-covariant Lagrangian formulation of gravitational theories with the presence of spinor matter fields. The invariance properties of such theories give rise to the conservation laws (the contracted Bianchi identities) having in the presence of matter fields a more complicated form than those known in the literature previously. A general SL(2,C) gauge theory of gravity is cast into an SL(2,C)-covariant Hamiltonian formulation. Breaking the SL(2,C) symmetry of the system to the SU(2) symmetry, by introducing a spacelike slicing of spacetime, we get an SU(2)-covariant Hamiltonian picture. The qualitative analysis of SL(2,C) gauge theories of gravity in the SU(2)-covariant formulation enables us to define the dynamical symplectic variables and the gauge variables of the theory under consideration as well as to divide the set of field equations into the dynamical equations and the constraints. In the SU(2)-covariant Hamiltonian formulation the primary constraints, which are generic for first-order matter Lagrangians (Dirac, Weyl, Fierz-Pauli), can be reduced. The effective matter symplectic variables are given by SU(2)-spinor-valued half-forms on three-dimensional slices of spacetime. The coupled Einstein-Cartan-Dirac (Weyl, Fierz-Pauli) system is analyzed from the (3+1) point of view. This analysis is complete; the field equations of the Einstein-Cartan-Dirac theory split into 18 gravitational dynamical equations, 8 dynamical Dirac equations, and 7 first-class constraints. The system has 4+8=12 independent degrees of freedom in the phase space.

  14. Spinor matter fields in SL(2,C) gauge theories of gravity: Lagrangian and Hamiltonian approaches

    International Nuclear Information System (INIS)

    Antonowicz, M.; Szczyrba, W.

    1985-01-01

    We consider the SL(2,C)-covariant Lagrangian formulation of gravitational theories with the presence of spinor matter fields. The invariance properties of such theories give rise to the conservation laws (the contracted Bianchi identities) having in the presence of matter fields a more complicated form than those known in the literature previously. A general SL(2,C) gauge theory of gravity is cast into an SL(2,C)-covariant Hamiltonian formulation. Breaking the SL(2,C) symmetry of the system to the SU(2) symmetry, by introducing a spacelike slicing of spacetime, we get an SU(2)-covariant Hamiltonian picture. The qualitative analysis of SL(2,C) gauge theories of gravity in the SU(2)-covariant formulation enables us to define the dynamical symplectic variables and the gauge variables of the theory under consideration as well as to divide the set of field equations into the dynamical equations and the constraints. In the SU(2)-covariant Hamiltonian formulation the primary constraints, which are generic for first-order matter Lagrangians (Dirac, Weyl, Fierz-Pauli), can be reduced. The effective matter symplectic variables are given by SU(2)-spinor-valued half-forms on three-dimensional slices of spacetime. The coupled Einstein-Cartan-Dirac (Weyl, Fierz-Pauli) system is analyzed from the (3+1) point of view. This analysis is complete; the field equations of the Einstein-Cartan-Dirac theory split into 18 gravitational dynamical equations, 8 dynamical Dirac equations, and 7 first-class constraints. The system has 4+8 = 12 independent degrees of freedom in the phase space

  15. Black holes with su(N) gauge field hair and superconducting horizons

    Energy Technology Data Exchange (ETDEWEB)

    Shepherd, Ben L.; Winstanley, Elizabeth [Consortium for Fundamental Physics, School of Mathematics and Statistics,The University of Sheffield,Hicks Building, Hounsfield Road, Sheffield S3 7RH (United Kingdom)

    2017-01-16

    We present new planar dyonic black hole solutions of the su(N) Einstein-Yang-Mills equations in asymptotically anti-de Sitter space-time, focussing on su(2) and su(3) gauge groups. The magnetic part of the gauge field forms a condensate close to the planar event horizon. We compare the free energy of a non-Abelian hairy black hole with that of an embedded Reissner-Nordström-anti-de Sitter (RN-AdS) black hole having the same Hawking temperature and electric charge. We find that the hairy black holes have lower free energy. We present evidence that there is a phase transition at a critical temperature, above which the only solutions are embedded RN-AdS black holes. At the critical temperature, an RN-AdS black hole can decay into a hairy black hole, and it is thermodynamically favourable to do so. Working in the probe limit, we compute the frequency-dependent conductivity, and find that enlarging the gauge group from su(2) to su(3) eliminates a divergence in the conductivity at nonzero frequency.

  16. Black holes with su(N) gauge field hair and superconducting horizons

    International Nuclear Information System (INIS)

    Shepherd, Ben L.; Winstanley, Elizabeth

    2017-01-01

    We present new planar dyonic black hole solutions of the su(N) Einstein-Yang-Mills equations in asymptotically anti-de Sitter space-time, focussing on su(2) and su(3) gauge groups. The magnetic part of the gauge field forms a condensate close to the planar event horizon. We compare the free energy of a non-Abelian hairy black hole with that of an embedded Reissner-Nordström-anti-de Sitter (RN-AdS) black hole having the same Hawking temperature and electric charge. We find that the hairy black holes have lower free energy. We present evidence that there is a phase transition at a critical temperature, above which the only solutions are embedded RN-AdS black holes. At the critical temperature, an RN-AdS black hole can decay into a hairy black hole, and it is thermodynamically favourable to do so. Working in the probe limit, we compute the frequency-dependent conductivity, and find that enlarging the gauge group from su(2) to su(3) eliminates a divergence in the conductivity at nonzero frequency.

  17. From the Dyson-Schwinger to the Transport Equation in the Background Field Gauge of QCD

    CERN Document Server

    Wang, Q; Stöcker, H; Greiner, W

    2003-01-01

    The non-equilibrium quantum field dynamics is usually described in the closed-time-path formalism. The initial state correlations are introduced into the generating functional by non-local source terms. We propose a functional approach to the Dyson-Schwinger equation, which treats the non-local and local source terms in the same way. In this approach, the generating functional is formulated for the connected Green functions and one-particle-irreducible vertices. The great advantages of our approach over the widely used two-particle-irreducible method are that it is much simpler and that it is easy to implement the procedure in a computer program to automatically generate the Feynman diagrams for a given process. The method is then applied to a pure gluon plasma to derive the gauge-covariant transport equation from the Dyson-Schwinger equation in the background covariant gauge. We discuss the structure of the kinetic equation and show its relationship with the classical one. We derive the gauge-covariant colli...

  18. Local fields and effective conductivity tensor of ellipsoidal particle composite with anisotropic constituents

    Science.gov (United States)

    Kushch, Volodymyr I.; Sevostianov, Igor; Giraud, Albert

    2017-11-01

    An accurate semi-analytical solution of the conductivity problem for a composite with anisotropic matrix and arbitrarily oriented anisotropic ellipsoidal inhomogeneities has been obtained. The developed approach combines the superposition principle with the multipole expansion of perturbation fields of inhomogeneities in terms of ellipsoidal harmonics and reduces the boundary value problem to an infinite system of linear algebraic equations for the induced multipole moments of inhomogeneities. A complete full-field solution is obtained for the multi-particle models comprising inhomogeneities of diverse shape, size, orientation and properties which enables an adequate account for the microstructure parameters. The solution is valid for the general-type anisotropy of constituents and arbitrary orientation of the orthotropy axes. The effective conductivity tensor of the particulate composite with anisotropic constituents is evaluated in the framework of the generalized Maxwell homogenization scheme. Application of the developed method to composites with imperfect ellipsoidal interfaces is straightforward. Their incorporation yields probably the most general model of a composite that may be considered in the framework of analytical approach.

  19. Coupled inflaton and electromagnetic fields from Gravitoelectromagnetic Inflation with Lorentz and Feynman gauges

    International Nuclear Information System (INIS)

    Membiela, Federico Agustín; Bellini, Mauricio

    2010-01-01

    Using a semiclassical approach to Gravitoelectromagnetic Inflation (GEMI), we study the origin and evolution of seminal inflaton and electromagnetic fields in the early inflationary universe from a 5D vacuum state. We use simultaneously the Lorentz and Feynman gauges. Our formalism is naturally not conformal invariant on the effective 4D de Sitter metric, which make possible the super adiabatic amplification of electric and magnetic field modes during the early inflationary epoch of the universe on cosmological scales. This is the first time that solutions for the electric field fluctuations are investigated in a systematic way as embeddings for inflationary models in 4D. An important and new result here obtained is that the spectrum of the electric field fluctuations depend with the scale, such that the spectral index increases quadratically as the scale decreases

  20. Coupled inflaton and electromagnetic fields from Gravitoelectromagnetic Inflation with Lorentz and Feynman gauges

    Energy Technology Data Exchange (ETDEWEB)

    Membiela, Federico Agustín; Bellini, Mauricio, E-mail: mbellini@mdp.edu.ar, E-mail: membiela@mdp.edu.ar [Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, Funes 3350, (7600) Mar del Plata (Argentina)

    2010-10-01

    Using a semiclassical approach to Gravitoelectromagnetic Inflation (GEMI), we study the origin and evolution of seminal inflaton and electromagnetic fields in the early inflationary universe from a 5D vacuum state. We use simultaneously the Lorentz and Feynman gauges. Our formalism is naturally not conformal invariant on the effective 4D de Sitter metric, which make possible the super adiabatic amplification of electric and magnetic field modes during the early inflationary epoch of the universe on cosmological scales. This is the first time that solutions for the electric field fluctuations are investigated in a systematic way as embeddings for inflationary models in 4D. An important and new result here obtained is that the spectrum of the electric field fluctuations depend with the scale, such that the spectral index increases quadratically as the scale decreases.