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1

Gauge dependence of the gravitational conformal anomaly for the electromagnetic field

International Nuclear Information System (INIS)

The conformal anomaly for the electromagnetic field in the background gravitational field is obtained in the general covatiant gauge with a gauge parameter. We have used the path integral method of Fujikawa with the zeta-regularization. The gauge dependence is observed in the coefficient of the vacantR term in the anomaly; various contradicting values have been assigned to the coefficient of this term in the previous calculations on the basis of different regularization schemes in the Feynman gauge. We emphasize that at the cost of the classical conformal invariance those terms can be eliminated altogether by adding a finite counterterm proportional to ?gR2 to the Lagrangian. A calculational scheme with regularized Green functions was also examined, and it gives rise to the same r esults for the anomaly in the conventional Faddeev-Popov formalism as well as in the B-field formalism. The regularization of Green functions introduces an auxiliary mass parameter for each field and the Ward-Takahashi identities impose a condition among those mass parameters. In the framework of the zeta-function regularization, the gauge dependence of the vacantR term in the anomaly thus appears to be inevitable. (author)

2

International Nuclear Information System (INIS)

In quantum systems with an infinite number of degrees of freedom loop corrections may break symmetries of original Lagrangian. This phenomenon, referred to as quantum anomaly, appears to be due to the need of regularization, i.e., the definition of the theory in ultraviolet domain. Such a definition unavoidably contradicts certain symmetries of the classical theory. In particular, it leads to nonconservation of the corresponding Noether currents. In the present review the origin of anomalies and their role in the structure of modern field-theoretical models are discussed. Anomalies in internal currents of gauge theories are of special importance. They may induce a loss of invariance with respect to either infinitesimal or global gauge transformations, resulting in nonself-contented theory. Anomaly cancellation condition severely restricts the field content and the choice of interactions in realistic models. The methods of anomally calculations are discussed in details. The special attention is played to nonconservation of axial and chiral fermionic currents. The elementary concept of the hierarchy of anomalies is presented. A special section treats global anomalies, in particular the Witten's SU(2) one, and analogous phenomenon in odd-dimensional Yang-Mills theories

3

Fluid/Gravity Correspondence, Second Order Transport and Gravitational Anomaly*,**

Directory of Open Access Journals (Sweden)

Full Text Available We study the transport properties of a relativistic fluid affected by chiral and gauge-gravitational anomalies. The computation is performed in the framework of the fluid/gravity correspondence for a 5 dim holographic model with Chern-Simons terms in the action. We find new anomalous and non anomalous transport coefficients, as well as new contributions to the existing ones coming from the mixed gauge-gravitational anomaly. Consequences for the shear waves dispersion relation are analyzed.

Megías Eugenio

2014-03-01

4

Gravitational Anomaly and Transport Phenomena

International Nuclear Information System (INIS)

Quantum anomalies give rise to new transport phenomena. In particular, a magnetic field can induce an anomalous current via the chiral magnetic effect and a vortex in the relativistic fluid can also induce a current via the chiral vortical effect. The related transport coefficients can be calculated via Kubo formulas. We evaluate the Kubo formula for the anomalous vortical conductivity at weak coupling and show that it receives contributions proportional to the gravitational anomaly coefficient. The gravitational anomaly gives rise to an anomalous vortical effect even for an uncharged fluid.

5

During the last five decades, gravity, as one of the fundamental forces of nature, has been formulated as a gauge field theory of the Weyl-Cartan-Yang-Mills type. The resulting theory, the Poincar\\'e gauge theory of gravity, encompasses Einstein's gravitational theory as well as the teleparallel theory of gravity as subcases. In general, the spacetime structure is enriched by Cartan's torsion and the new theory can accommodate fermionic matter and its spin in a perfectly natural way. The present reprint volume contains articles from the most prominent proponents of the theory and is supplemented by detailed commentaries of the editors. This guided tour starts from special relativity and leads, in its first part, to general relativity and its gauge type extensions a la Weyl and Cartan. Subsequent stopping points are the theories of Yang-Mills and Utiyama and, as a particular vantage point, the theory of Sciama and Kibble. Later, the Poincar\\'e gauge theory and its generalizations are explored and specific topi...

Blagojevi?, Milutin

2012-01-01

6

Anomaly cancellation condition in lattice gauge theory

International Nuclear Information System (INIS)

We study the gauge anomaly A defined on a 4-dimensional infinite lattice while keeping the lattice spacing finite. We assume that (I) A depends smoothly and locally on the gauge potential, (II) A reproduces the gauge anomaly in the continuum theory in the classical continuum limit, and (III) U(1) gauge anomalies have a topological property. It is then shown that the gauge anomaly A can always be removed by local counterterms to all orders in powers of the gauge potential, leaving possible breakings proportional to the anomaly in the continuum theory. This follows from an analysis of nontrivial local solutions to the Wess-Zumino consistency condition in lattice gauge theory. Our result is applicable to the lattice chiral gauge theory based on the Ginsparg-Wilson Dirac operator, when the gauge field is sufficiently weak parallel U(n,?)-1 parallel

7

Review on possible gravitational anomalies

Energy Technology Data Exchange (ETDEWEB)

This is an updated introductory review of 2 possible gravitational anomalies that has attracted part of the Scientific community: the Allais effect that occur during solar eclipses, and the Pioneer 10 spacecraft anomaly, experimented also by Pioneer 11 and Ulysses spacecrafts. It seems that, to date, no satisfactory conventional explanation exist to these phenomena, and this suggests that possible new physics will be needed to account for them. The main purpose of this review is to announce 3 other new measurements that will be carried on during the 2005 solar eclipses in Panama and Colombia (Apr. 8) and in Portugal (Oct.15)

Amador, Xavier E [Centro de Investigacion y Estudios Avanzados, CINVESTAV, Dept. of Physics, Av. IPN 2508, 07000 Ciudad de Mexico, D.F. (Mexico)

2005-01-15

8

Review on possible gravitational anomalies

International Nuclear Information System (INIS)

This is an updated introductory review of 2 possible gravitational anomalies that has attracted part of the Scientific community: the Allais effect that occur during solar eclipses, and the Pioneer 10 spacecraft anomaly, experimented also by Pioneer 11 and Ulysses spacecrafts. It seems that, to date, no satisfactory conventional explanation exist to these phenomena, and this suggests that possible new physics will be needed to account for them. The main purpose of this review is to announce 3 other new measurements that will be carried on during the 2005 solar eclipses in Panama and Colombia (Apr. 8) and in Portugal (Oct.15)

9

Review on possible gravitational anomalies

This is an updated introductory review of 2 possible gravitational anomalies that has attracted part of the Scientific community: the Allais effect that occur during solar eclipses, and the Pioneer 10 spacecraft anomaly, experimented also by Pioneer 11 and Ulysses spacecrafts. It seems that, to date, no satisfactory conventional explanation exist to these phenomena, and this suggests that possible new physics will be needed to account for them. The main purpose of this review is to announce 3 other new measurements that will be carried on during the 2005 solar eclipses in Panama and Colombia (Apr. 8) and in Portugal (Oct.15).

Amador, X E

2005-01-01

10

Chiral and Gravitational Anomalies on Fermi Surfaces

A Fermi surface threaded by a Berry phase can be described by the Wess-Zumino-Witten (WZW) term. After gauging, it produces a five-dimensional Chern-Simons term in the action. We show how this Chern-Simons term captures the essence of the Abelian, non-Abelian, and mixed gravitational anomalies in describing both in- and off-equilibrium phenomena. In particular we derive a novel contribution to the Chiral Vortical Effect that arises when a temperature gradient is present. We also discuss the issue of universality of the anomalous currents.

Basar, Gokce; Zahed, Ismail

2013-01-01

11

Chiral gauge symmetry without anomalies

International Nuclear Information System (INIS)

The Ward identities derived by use of chiral gauge symmetry, when examined in a perturbation expansion using Lagrangian field theory, are found to contain the Adler-Bell-Jackiw-Schwinger anomalies. The cause of this shortcoming is examined, and the result is that when one uses a formulation of field theory in which only fields already renormalized are introduced these anomalies disappear completely. The specific cases examined here are massless two-dimensional electrodynamics with a vector coupling and massless four-dimensional electrodynamics with an axial-vector coupling. In the first example, it is also found that the polarization tensor disappears in second order, and does not exhibit a pole at zero momentum transfer that would cause the vector field to generate a mass spontaneously

12

Hawking radiation via higher-spin gauge anomalies

International Nuclear Information System (INIS)

We give a higher-spin generalization of the anomaly method for the Hawking radiation from black holes. In the paper [S. Iso, T. Morita, and H. Umetsu, arXiv:0710.0453.] higher-spin generalizations of the gauge (and gravitational) anomalies in d=2 were obtained. By applying these anomalies to black hole physics, we derive the higher moments of the Hawking fluxes. We also give a higher-spin generalization of the trace anomaly method by Christensen and Fulling [S. Christensen and S. Fulling, Phys. Rev. D 15, 2088 (1977).

13

Gravitation and Gauge Symmetries

International Nuclear Information System (INIS)

The purpose of this book (I quote verbatim from the back cover) is to 'shed light upon the intrinsic structure of gravity and the principle of gauge invariance, which may lead to a consistent unified field theory', a very laudable aim. The content divides fairly clearly into four sections (and origins). After a brief introduction, chapters 2-6 review the 'Structure of gravity as a theory based on spacetime gauge symmetries'. This is fairly straightforward material, apparently based on a one-semester graduate course taught at the University of Belgrade for about two decades, and, by implication, this is a reasonably accurate description of its level and assumed knowledge. There follow two chapters of new material entitled 'Gravity in flat spacetime' and 'Nonlinear effects in gravity'. The final three chapters, entitled 'Supersymmetry and supergravity', 'Kaluza-Klein theory' and 'String theory' have been used for the basis of a one-semester graduate course on the unification of fundamental interactions. The book concludes with thirteen appendices, covering mainly technical issues but also including Ashtekhar variables and Chern-Simons theory. Irritatingly, there is a separate bibliography for each chapter (which leads to much duplication) but commendably, the author highlights selected sources for suitable further reading. Also to be welcomed wholeheartedly are well-chosen worked examples and exercises, ranging from easy to fairly challenging, in each chapter. This is aly challenging, in each chapter. This is a properly bound paperback, hardly inexpensive, but well up to IOP's impeccable production standards. Could this be the ideal textbook for a research student or even an established researcher from another field to pick up the latest developments in field theory? Unfortunately this is not the whole story. The back cover also asserts, while talking about gauge invariance, that 'It is less known that the principle of equivalence, one of the basic dynamical properties of the gravitational interaction, can be expressed as a (spacetime) gauge symmetry'. On page 10 this is qualified to be a local symmetry. On pages 62-3 this hidden result is revealed. As every relativist knows, the principle of equivalence implies that for each spacetime point p a chart (normal coordinates at p) can be chosen so that the metric tensor takes its Minkowski value and its (partial) derivatives vanish at p. In other words every (pseudo-)Riemannian manifold is locally flat, the 'less known' result. So what else can the author tell us about gravity? There is little to fault in the first two sections of the book, trying to express gravity as a nonlinear spin-2 theory on Minkowski spacetime, apart from the obvious objection. A well-known and highly-recommendable textbook by S Weinberg 1972 Gravitation and Cosmology (New York: Wiley), carries out, at a more elementary level, a similar programme with the same defect. Such local theories cannot predict global changes whereby spacetime has a different topology to the Minkowski one. (The unconvinced reader should investigate references to black holes in Weinberg's text.) As speaker after speaker at the S W Hawking 60th Birthday Conference last week emphasized, when trying to unify gravity with quantum theory, it is perilous to neglect geometry. Because the later chapters on supersymmetry, supergravity, Kaluza-Klein and string theories are more fashionable, I need to point out an important caveat. Excluding textbooks and conference volumes, all (English language) citations in the supersymmetry/supergravity chapter are at least 16 years old. Apart from one 2000 article (on teleparallel theory) this age gap drops by three years for the chapter on Kaluza-Klein theory, and it does not change any further for the string theory chapter. There have been more recent significant advances in our understanding and interpretation of these theories but, alas, they are not chronicled here. I raised a question as to the value of this book at the end of the first paragraph, and I want to answer it within the context of the

14

Anomaly cancellation condition in lattice gauge theory

International Nuclear Information System (INIS)

We show that, to all orders of powers of the gauge potential, a gauge anomaly ? defined on 4-dimensional infinite lattice can always be removed by a local counterterm, provided that ? depends smoothly and locally on the gauge potential and that ? reproduces the gauge anomaly in the continuum theory in the classical continuum limit: The unique exception is proportional to the anomaly in the continuum theory. This follows from an analysis of nontrivial local solutions to the Wess-Zumino consistency condition in lattice gauge theory. Our result is applicable to the lattice chiral gauge theory based on the Ginsparg-Wilson Dirac operator, when the gauge field is sufficiently weak parallel-U(n,?) - 1-parallel < ?', where U(n,?) is the link variable and ?' a certain small positive constant. (author)

15

Discrete Gauge Anomalies in Orbifold Models

Discrete gauge anomalies in string theory models are discussed. Results of a study of ~ 10,000 orbifold compactifications of the heterotic string and ~30 Type II models are reported. The study finds that in all models examined, the discrete gauge anomalies can be cancelled through a Green-Schwarz type mechanism. The work begins with a discussion of discrete gauge symmetries. There is an introduction to string theory, a chapter on compactification, and an explanation of orbifold models. The results of the computer search of orbifold compactifications of heterotic string models is then discussed. In Part II, there are introductory chapters explaining conformal field theory and superconformal field theory. Type II string models with gauge symmetries are then described, and the results of an examination of discrete gauge anomalies in these models is reported. A final chapter discusses the overall results and questions for future research. There are five appendices describing important topics used throughout the thesis.

Macintire, Douglas Alan

16

Gravitation and Gauge Symmetries

The purpose of this book (I quote verbatim from the back cover) is to 'shed light upon the intrinsic structure of gravity and the principle of gauge invariance, which may lead to a consistent unified field theory', a very laudable aim. The content divides fairly clearly into four sections (and origins). After a brief introduction, chapters 2-6 review the 'Structure of gravity as a theory based on spacetime gauge symmetries'. This is fairly straightforward material, apparently based on a one-semester graduate course taught at the University of Belgrade for about two decades, and, by implication, this is a reasonably accurate description of its level and assumed knowledge. There follow two chapters of new material entitled 'Gravity in flat spacetime' and 'Nonlinear effects in gravity'. The final three chapters, entitled 'Supersymmetry and supergravity', 'Kaluza-Klein theory' and 'String theory' have been used for the basis of a one-semester graduate course on the unification of fundamental interactions. The boo...

Stewart, J

2002-01-01

17

Trace and dilation anomalies in gauge theories

International Nuclear Information System (INIS)

The form of the anomaly in the trace of the energy-momentum tensor in a general theory of interacting fermions and non-Abelian gauge bosons is derived. The result is shown to involve precisely those gauge-variant operators which are known to mix with the naive trace under renormalization. The trace is shown to be soft on the mass shell if and only if the theory is at an eigenvalue of the Callan-Symanzik ? function. The dilatation anomaly in the matrix element of theta/sup lambda /lambda with two electromagnetic currents (to lowest order in electromagnetism, but including all orders of the strong gauge interaction) is derived and shown to be infinitely renormalized in finite orders of strong perturbation theory. This anomaly is then shown to be canonical and given precisely by the lowest-order result provided the strong interactions are summed to all orders before going to the limit of physical space-time dimensions

18

Interpretation of Venus gravitational anomalies

International Nuclear Information System (INIS)

The Venus gravity field anomalies are interpreted from three harmonics of potential expansion. Masses and depths of the anomaly centers in three regions: the Aphrodita land, the Ishtar land and in the South of the planet, are defined from the Venus geoid height, pure anomaly of attractive force, and plumb deviation. These depths are determined to be 930-1140 km. Analogous Earth anomalies in the field smoothing from 16 to 3 harmonics are characterized by depth overestimation. 1.4-times. Because of this, depths of the Venus anomaly sources reduced to 16 harmonics lie approximately in the range of 700-800 km, that is they correspond to the depth of bedding of the Venus mantle second phase boundary

19

Gauge invariant gravitation theory. 1. Gravitational field source and spin

International Nuclear Information System (INIS)

It is shown that gauge invariance occurs as the consequence of physical field (fields with certain spin) description by the values, transformed as irreducible representations of homogeneous Lorentz group. Gauge-invariant lagrangian of the field of 2 spin was constructed. It was proved that gravitational field represented the superposition of gauge-invariant fields of 2 and 0 spins. Occurrence of the zero spin field is directly related with nonpreservation of the (gauge-invariant) source of gravitational field

20

Universally Finite Gravitational & Gauge Theories

It is well known that standard gauge theories are renormalizable in D=4 while Einstein gravity is renormalizable in D=2. This is where the research in the field of two derivatives theories is currently standing. We hereby present a class of weakly non-local higher derivative gravitational and gauge theories universally consistent at quantum level in any spacetime dimension. These theories are unitary (ghost-free) and perturbatively renormalizable. Moreover, we can always find a simple extension of these theories that is super-renormalizable or finite at quantum level in even and odd spacetime dimensions. Finally, we propose a super-renormalizable or finite theory for gravity coupled to matter laying the groundwork for a "finite standard model of particle physics" and/or a grand unified theory of all fundamental interactions.

Modesto, Leonardo

2015-01-01

21

Holographic entanglement entropy and gravitational anomalies

We study entanglement entropy in two-dimensional conformal field theories with a gravitational anomaly. In theories with gravity duals, this anomaly is holographically represented by a gravitational Chern-Simons term in the bulk action. We show that the anomaly broadens the Ryu-Takayanagi minimal worldline into a ribbon, and that the anomalous contribution to the CFT entanglement entropy is given by the twist in this ribbon. The entanglement functional may also be interpreted as the worldline action for a spinning particle — that is, an anyon — in three-dimensional curved spacetime. We demonstrate that the minimization of this action results in the Mathisson-Papapetrou-Dixon equations of motion for a spinning particle in three dimensions. We work out several simple examples and demonstrate agreement with CFT calculations.

Castro, Alejandra; Detournay, Stephane; Iqbal, Nabil; Perlmutter, Eric

2014-07-01

22

Holographic entanglement entropy and gravitational anomalies

We study entanglement entropy in two-dimensional conformal field theories with a gravitational anomaly. In theories with gravity duals, this anomaly is holographically represented by a gravitational Chern-Simons term in the bulk action. We show that the anomaly broadens the Ryu-Takayanagi minimal worldline into a ribbon, and that the anomalous contribution to the CFT entanglement entropy is given by the twist in this ribbon. The entanglement functional may also be interpreted as the worldline action for a spinning particle -- that is, an anyon -- in three-dimensional curved spacetime. We demonstrate that the minimization of this action results in the Mathisson-Papapetrou-Dixon equations of motion for a spinning particle in three dimensions. We work out several simple examples and demonstrate agreement with CFT calculations.

Castro, Alejandra; Iqbal, Nabil; Perlmutter, Eric

2014-01-01

23

Gauge Symmetries and Holographic Anomalies of Chern-Simons and Transgression AdS Gravity

We review the issue of gauge and gravitational anomalies with backgrounds, maybe offering a new outlook on some aspects of these questions. We compute the holographic anomalies of hypothetical theories dual, in the sense of the AdS-CFT correspondence, to Chern-Simons AdS gravities. Those anomalies are either gauge anomalies associated to the AdS gauge group of the theory or diffeomorphism anomalies, with each kind related to the other. As a result of using suitable action principles por Chern-Simons AdS gravities, coming from Transgression forms, we obtain finite results without the need for further regularization. Our results are of potential interest for Lovelock gravity theories, as it has been shown that the boundary terms dictated by the transgressions for Chern-Simons gravities are also suitable to regularize Lovelock theories. The Wess-Zumino consistency condition ensures that anomalies of the generic form computed here should appear for these and other theories.

Mora, Pablo

2014-01-01

24

Gauge Anomalies and Neutrino Seesaw Models

Despite the success of the Standard Model concerning theoretical predictions, there are several experimental results that cannot be explained and there are reasons to believe that there exists new physics beyond it. Neutrino oscillations, and hence their masses, are examples of this. Experimentally it is known that neutrinos masses are quite small, when compared to all Standard Model particle masses. Among the theoretical possibilities to explain these tiny masses, the seesaw mechanism is a simple and well-motivated framework. In its minimal version, heavy particles are introduced that decouple from the theory in the early universe. To build consistent theories, classical symmetries need to be preserved at quantum level, so that there are no anomalies. The cancellation of these anomalies leads to constraints in the parameters of the theory. One attractive solution is to realize the anomaly cancellation through the modication of the gauge symmetry. In this thesis we present a short review of some features of t...

Neves Cebola, Luis Manuel

25

Noncommutative chiral gravitational anomalies in two dimensions

Scientific Electronic Library Online (English)

Full Text Available SciELO Mexico | Language: English Abstract in spanish Se examinan las anomalías gravitacionales en un espacio no conmutativo. El análisis es general e independiente de alguna teoría de gravedad no conmutativa específica y depende sólo de cómo la gravedad se acople a los fermiones quirales. El cálculo de Delbourgo-Salam de la correccción gravitacional a [...] la anomalía axial ABJ se estudia en detalle en este contexto. Finalmente se muestra que la anomalía gravitacional en dos dimensiones no admite correcciones no conmutativas en el parámetro ?. Abstract in english Gravitational anomalies in a noncommutative space are examined. The analysis is generic and independent of a particular noncommutative theory of gravity, and it depends only on how gravity is noncommutatively coupled to chiral fermions. Delbourgo-Salam computation of the gravitational correction of [...] the axial ABJ-anomaly is studied in detail in this context. Finally, we show that the two-dimensional gravitational anomaly does not permit noncommutative corrections in the parameter ?.

H, García-Compeán; C, Soto-Campos.

2007-02-01

26

Gravitational anomalies in the solar system?

Mindful of the anomalous perihelion precession of Mercury discovered by Le Verrier in the second half of the nineteenth century and its successful explanation by Einstein with his General Theory of Relativity in the early years of the twentieth century, discrepancies among observed effects in our Solar system and their theoretical predictions on the basis of the currently accepted laws of gravitation applied to known matter-energy distributions have the potential of paving the way for remarkable advances in fundamental physics. This is particularly important now more than ever, given that most of the universe seems to be made of unknown substances dubbed Dark Matter and Dark Energy. Should this not be directly the case, Solar system's anomalies could anyhow lead to advancements in either cumulative science, as shown to us by the discovery of Neptune in the first half of the nineteenth century, and technology itself. Moreover, investigations in one of such directions can serendipitously enrich the other one as well. The current status of some alleged gravitational anomalies in the Solar system is critically reviewed. They are: (a) Possible anomalous advances of planetary perihelia. (b) Unexplained orbital residuals of a recently discovered moon of Uranus (Mab). (c) The lingering unexplained secular increase of the eccentricity of the orbit of the Moon. (d) The so-called Faint Young Sun Paradox. (e) The secular decrease of the mass parameter of the Sun. (f) The Flyby Anomaly. (g) The Pioneer Anomaly. (h) The anomalous secular increase of the astronomical unit.

Iorio, Lorenzo

2015-03-01

27

More on the Z-string global gauge anomaly

Certain (3+1)-dimensional chiral non-Abelian gauge theories have been shown to exhibit a new type of global gauge anomaly, which in the hamiltonian formulation is due to the fermion zero-modes of the Z-string configuration and the corresponding spectral flow. Here, we clarify the relation between this Z-string global gauge anomaly and other anomalies in both 3+1 and 2+1 dimensions. We also point out a possible trade-off between the (3+1)-dimensional Z-string global gauge anomaly and the violation of Lorentz invariance.

Klinkhamer, F R

1998-01-01

28

Gravitation as Gauge theory of Poincare Group

International Nuclear Information System (INIS)

The geometrical approach to gauge theories, based on fiber-bundles, is shown in detail. Several gauge formalisms for gravitation are examined. In particular, it is shown how to build gauge theories for non-semisimple groups. A gravitational theory for the Poincare group, with all the essential characteristics of a Yang-Mills theory is proposed. Inonu-Wigner contractions of gauge theories are introduced, which provide a Lagrangian formalism, equivalent to a Lagrangian de Sitter theory supplemented by weak constraints. Yang and Einstein theories for gravitation become particular cases of a Yang-Mills theory. The classical limit of the proposed formalism leads to the Poisson equation, for the static case. (Author)

29

Gravitational rescue of minimal gauge mediation

Gravity mediation supersymmetry breaking become comparable to gauge mediated supersymmetry breaking contributions when messenger masses are close to the GUT scale. By suitably tuning the gravity contributions one can then modify the soft supersymmetry breaking sector to generate a large stop mixing parameter and a light higgs mass of 125 GeV. In this kind of hybrid models, however the nice features of gauge mediation like flavour conservation etc, are lost. To preserve the nice features, gravitational contributions should become important for lighter messenger masses and should be important only for certain fields. This is possible when the hidden sector contains multiple (at least two) spurions with hierarchical vaccum expectation values. In this case, the gravitational contribtutions can be organised to be `just right'. We present a complete model with two spurion hidden sector where the gravitational contribution is from a warped flavour model in a Randall-Sundrum setting. Along the way, we present simple ...

Iyer, Abhishek M; Vempati, Sudhir K

2014-01-01

30

Chiral photon current and its anomaly in a gravitational field

International Nuclear Information System (INIS)

The concept of chirality which is conserved in the interaction with a gravitational field is formulated for an electromagnetic field. The corresponding current is a one-particle analog of the Pauli-Lubanski vector. An anomaly in the divergence of the current in an external gravitational field is found. The result is used to determine the electromagnetic radiative correction to the chiral anomaly of a fermion in a gravitational field

31

Removal of chiral anomalies in abelian gauge theories

International Nuclear Information System (INIS)

It is shown that chiral anomalies can be removed in abelian gauge theories. After a discussion of the two dimensional case where exact solutions are available we study the four dimensional theory. We use perturbation theory, i.e. analyse the triangle Feynman integrals, and determine the general subtraction structure of the gauge current. Then we show that gauges exist for which current conservation holds and the theory is gauge invariant. As far as the generating functional is concerned the anomaly is employed first as gauge fixing condition. After rewriting the interaction in a gauge invariant form the gauge fixing condition can be imposed as usual. In our approach the integration over the gauge group remains trivial. (author)

32

Maps for currents and anomalies in noncommutative gauge theories

International Nuclear Information System (INIS)

We derive maps relating currents and their divergences in non-Abelian U(N) noncommutative gauge theory with the corresponding expressions in the ordinary (commutative) description. For the U(1) theory, in the slowly-varying-field approximation, these maps are also seen to connect the star-gauge-covariant anomaly in the noncommutative theory with the standard Adler-Bell-Jackiw anomaly in the commutative version. For arbitrary fields, derivative corrections to the maps are explicitly computed up to O(?2)

33

Nonperturbative scale anomaly and dilaton in gauge field theories

International Nuclear Information System (INIS)

The scale anomaly caused by the dynamics of spontaneous chiral symmetry breaking is studied in vector-like gauge theories. The contribution of this anomaly to the gluon condensate and dilaton mass is determined. The criterion for the realization of the dynamics of a light dilaton is obtained. The applications of these results to quantum chromodynamics and technicolour models are considered

34

Anomaly cancellation in three-dimensional noncommutative gauge theories

International Nuclear Information System (INIS)

The anomaly found by Callan and Harvey is shown to be cancelled in a three-dimensional noncommutative gauge theory coupled to a fermion with a mass function depending on one spatial coordinate (domain wall mass). This evaluation has been done for the fermion in the fundamental and adjoint representations of the gauge group in the limit of small noncommutativity ? parameter

35

Extension of Chern-Simons forms and new gauge anomalies

We present a general analysis of gauge invariant, exact and metric independent forms which can be constructed using higher rank field-strength tensors. The integrals of these forms over the corresponding space-time coordinates provides new topological Lagrangians. With these Lagrangians one can define gauge field theories which generalize the Chern-Simons quantum field theory. We also present explicit expressions for the potential gauge anomalies associated with the tensor g...

Antoniadis, Ignatios; Savvidy, George

2013-01-01

36

Spinning black holes in a gauge theory of gravitation

Spinning black holes are presented in terms of gauge fields in a commutative gauge theory of gravitation. The field strength tensor comes as a consequence of the particular ansatz for gauge fields. In order to obtain spinning black holes in a noncommutative gauge theory of gravitation is used an analytical procedure conceived in GRTensorII. To calculate the leading noncommutative corrections and to choose an appropriate noncommutative parameter are used recursive relations. The gauge fields and the field strength tensor for a spinning mass preserves some features of other cosmological solutions in the gauge theory of gravitation and the noncommutative corrections are expected to provide some important physical insights.

BabeÅ£i (Pretorian), Simona

2013-11-01

37

Dimensional regularization of gauge theories in spherical spacetime: Free field trace anomalies

International Nuclear Information System (INIS)

The O (n+1) covariant formulation of massless quantum electrodynamics in spherical spacetime is further developed to allow a calculation of energy-momentum tensor trace anomalies for the free Dirac, electromagnetic, and SU(2) gauge fields. The principal technical development is the construction of the Faddeev--Popov ghosts for electrodynamics and SU(2) Yang--Mills theory. This construction is unconventional first in that the gauge fixing term in the Lagrangian is not a perfect square, and second because it is necessary to remove radial as well as gauge degrees of freedom from the measure of the functional integral. The ghost fields are shown to satisfy a minimal scalar field equation. The free field effective action is found to be divergent in four dimensions, and is renormalized by the inclusion in the Lagrangian of a counterterm local in the gravitational fields. The energy-momentum tensor calculated from this renormalized effective action is shown to have a trace anomaly

38

Gravitational Quantum Foam and Supersymmetric Gauge Theories

We study K\\"{a}hler gravity on local SU(N) geometry and describe precise correspondence with certain supersymmetric gauge theories and random plane partitions. The local geometry is discretized, via the geometric quantization, to a foam of an infinite number of gravitational quanta. We count these quanta in a relative manner by measuring a deviation of the local geometry from a singular Calabi-Yau threefold, that is a A_{N-1} singularity fibred over \\mathbb{P}^1. With such a regularization prescription, the number of the gravitational quanta becomes finite and turns to be the perturbative prepotential for five-dimensional \\mathcal{N}=1 supersymmetric SU(N) Yang-Mills. These quanta are labelled by lattice points in a certain convex polyhedron on \\mathbb{R}^3. The polyhedron becomes obtainable from a plane partition which is the ground state of a statistical model of random plane partition that describes the exact partition function for the gauge theory. Each gravitational quantum of the local geometry is shown...

Maeda, T; Noma, Y; Tamakoshi, T; Maeda, Takashi; Nakatsu, Toshio; Noma, Yui; Tamakoshi, Takeshi

2005-01-01

39

Gravitational quantum foam and supersymmetric gauge theories

International Nuclear Information System (INIS)

We study Kahler gravity on local SU(N) geometry and describe precise correspondence with certain supersymmetric gauge theories and random plane partitions. The local geometry is discretized, via the geometric quantization, to a foam of an infinite number of gravitational quanta. We count these quanta in a relative manner by measuring a deviation of the local geometry from a singular Calabi-Yau threefold, that is a AN-1 singularity fibred over P1. With such a regularization prescription, the number of the gravitational quanta becomes finite and turns to be the perturbative prepotential for five-dimensional N=1 supersymmetric SU(N) Yang-Mills. These quanta are labelled by lattice points in a certain convex polyhedron on R3. The polyhedron becomes obtainable from a plane partition which is the ground state of a statistical model of random plane partition that describes the exact partition function for the gauge theory. Each gravitational quantum of the local geometry is shown to consist of N unit cubes of plane partitions

40

REVIEWS OF TOPICAL PROBLEMS: Anomalies in gauge theories

In a quantum system with an infinite number of degrees of freedom, loop corrections may break symmetries of the original Lagrangian. This phenomenon, a "quantum anomaly," arises from the need for a "regularization": a supplemental definition of the theory in the ultraviolet region. A supplemental definition of this sort unavoidably runs into a contradiction with certain symmetries of the classical theory. In particular, it causes a nonconservation of corresponding Noether currents. Reasons for the appearance of anomalies and their place in the structure of modern field-theory models are discussed in this review. An emphasis is placed on anomalies in the internal currents of gauge theories. These anomalies may disrupt the invariance under infinitesimal or global gauge transformations, with the result that the theory is no longer self-consistent. The condition which must be met for the cancellation of internal anomalies severely restricts the composition of fields and the choice of interaction in realistic models. Methods for calculating anomalies are discussed in detail. Emphasis is placed on the nonconservation of axial and chiral fermion currents. The hierarchy of anomalies is introduced. A special section is devoted to global anomalies, in particular, Witten's SU(2) anomaly and a corresponding phenomenon in odd-dimensional Yang-Mills theories.

Morozov, A. Yu

1986-11-01

41

Gravitational Quantum Foam and Supersymmetric Gauge Theories

We study K\\"{a}hler gravity on local SU(N) geometry and describe precise correspondence with certain supersymmetric gauge theories and random plane partitions. The local geometry is discretized, via the geometric quantization, to a foam of an infinite number of gravitational quanta. We count these quanta in a relative manner by measuring a deviation of the local geometry from a singular Calabi-Yau threefold, that is a A_{N-1} singularity fibred over \\mathbb{P}^1. With such a...

Maeda, Takashi; Nakatsu, Toshio; Noma, Yui; Tamakoshi, Takeshi

2005-01-01

42

Hawking radiation for non-asymptotically flat dilatonic black holes using gravitational anomaly

International Nuclear Information System (INIS)

The d-dimensional scalar field action may be reduced, in the background geometry of a black hole, to a two-dimensional effective action. In the near-horizon region, it appears a gravitational anomaly: the energy-momentum tensor of the scalar field is not conserved anymore. This anomaly is removed by introducing a term related to the Hawking temperature of the black hole. Even if the temperature term introduced is not covariant, a gauge transformation may restore the covariance. We apply this method to compute the temperature of the dilatonic non-asymptotically flat black holes. We compare the results with those obtained through other methods. (orig.)

43

Global gauge anomaly of classical groups in even dimension

International Nuclear Information System (INIS)

Explicit expression of global gauge anomaly coefficients A(?) of locally anomaly-free representation ? of classical groups SU(N), Sp(2N) and SO(N) have been calculated in even dimensional space-time by uses of group theory and homotopy theory. As a by-product, we will prove some modular relations involving the n-th Kynkin indices Q/sub n/(?) of these groups. 11 refs

44

The hexagon gauge anomaly in Type 1 superstring theory

International Nuclear Information System (INIS)

Hexagon diagrams with external on-mass-shell Yang-Mills gauge particles are investigated in Type I superstring theory. Both the annulus and the Mobius-strip diagrams are shown to give anomalies, implying that spurious longitudinal modes cannot be consistently decoupled. However, the anomalies cancel when the two diagrams are added together if the gauge group is chosen to be SO(32). In carrying out the analysis, two different regulators are considered, but the same conclusions emerge in both cases. The authors point out where various terms in the low-energy effective action originate in superstring diagrams

45

Harada–Tsutsui gauge recovery procedure: From Abelian gauge anomalies to the Stueckelberg mechanism

International Nuclear Information System (INIS)

Revisiting a path-integral procedure developed by Harada and Tsutsui for recovering gauge invariance from anomalous effective actions, it is shown that there are two ways to achieve gauge symmetry: one already presented by the authors, which is shown to preserve the anomaly in the sense of standard current conservation law, and another one which is anomaly-free, preserving current conservation. It is also shown that the application of the Harada–Tsutsui technique to other models which are not anomalous but do not exhibit gauge invariance allows the identification of the gauge invariant formulation of the Proca model, also done by the referred authors, with the Stueckelberg model, leading to the interpretation of the gauge invariant map as a generalization of the Stueckelberg mechanism. -- Highlights: • A gauge restoration technique from Abelian anomalous models is discussed. • It is shown that there is another way that leads to gauge symmetry restoration from such technique. • It is shown that the first gauge restoration preserves the anomaly, while the proposed second one is free from anomalies. • It is shown that the proposed gauge symmetry restoration can be identified with the Stueckelberg mechanism

46

Renormalization of the gravitational trace anomaly in QED

International Nuclear Information System (INIS)

We evaluate to O (e2) in QED the effect of the electromagnetic coupling on the gravitational trace anomaly. The basis of the discussion is the calculation of the absorptive part of i. Using dimensional regularization we find as in the analogous calculation of sigma (e+e- ? hadrons) that the result is free of infrared singularities. By combining our results with those of Shore we are able to exhibit the complete gravitational trace anomaly to O (e2). The relationship of our results with the renormalization group is briefly discussed

47

Renormalisation of the gravitational trace anomaly in QED

International Nuclear Information System (INIS)

The effect of the electromagnetic coupling on the gravitational trace anomaly is evaluated to 0(e2) in QED. The basis of the discussion is the calculation of the absorptive part of i . Using dimensional regularisation it is found as in the analogous calculation of ?(e+e-? hadrons), that the result is free of infra-red singularities. By combining the present results with those of Shore(DAMTP Preprint 78/27) it is possible to exhibit the complete gravitational trace anomaly to 0(e2). The relationship of the present results with the renormalisation group is briefly discussed. (author)

48

Algebraic structure of chiral anomalies

International Nuclear Information System (INIS)

I will describe first the algebraic aspects of chiral anomalies, exercising however due care about the topological delicacies. I will illustrate the structure and methods in the context of gauge anomalies and will eventually make contact with results obtained from index theory. I will go into two sorts of generalizations: on the one hand, generalizing the algebraic set up yields e.g. gravitational and mixed gauge anomalies, supersymmetric gauge anomalies, anomalies in supergravity theories; on the other hand most constructions applied to the cohomologies which characterize anomalies easily extend to higher cohomologies. Section II is devoted to a description of the general set up as it applies to gauge anomalies. Section III deals with a number of algebraic set ups which characterize more general types of anomalies: gravitational and mixed gauge anomalies, supersymmetric gauge anomalies, anomalies in supergravity theories. It also includes brief remarks on ? models and a reminder on the full BRST algebra of quantized gauge theories

49

Spherical gauge gravitational field and spontaneous symmetry breaking

International Nuclear Information System (INIS)

Using a gauge theory of the gravitational field we build a metric with spherical symmetry. We use the theory based on the gravitational gauge group G to obtain a spherical symmetric solution of the field equations for the gravitational potentials. We define the gravitational gauge group G and then we introduce the gauge covariant derivative D?. The strength tensor of the gravitational gauge field is obtained and a gauge invariant Lagrangian is then constructed. The field equations of the gauge potentials are written and a gravitational energy-momentum tensor (Tg)?? is determined. In such a theory the motion of a test particle may be assimilated with a spontaneous symmetry breaking field theory: the gauge field that mediates the gravitational interaction between the source field and the test particle spontaneously breaks the vacuum symmetry, generating a Reissner-Nordstrom type metric. All the calculations have been performed by GR Tensor II computer algebra package, running on the Maple 7 platform, along with several routines that we have written for our model. (authors)

50

Anomaly of Tensionless String in Light-cone Gauge

The classical tensionless string theory has the spacetime conformal symmetry. We expect and require that the quantum tensionless string theory has it too. In the BRST quantization method, the theory has no spacetime conformal anomaly in two dimensions. On the other hand, in the light-cone gauge quantization without the mode expansion, the theory in $D>3$ has the spacetime conformal anomaly in the traceless part of $[\\mathcal{J}^{-I}, \\mathcal{K}^{J}]$ in some operator order. In this paper, we consider a tensionless closed bosonic string in the light-cone gauge and investigate the spacetime conformal anomaly in the theory with the mode expansion. The appearance of the spacetime conformal anomaly in the light-cone gauge is different between the case of $D>3$ and the case of $D=3$ and depends on the choice of the operator order. Therefore we must consider dangerous commutators in the spacetime conformal symmetry of $D>3$ and $D=3$ in each operator order separately. Specifically we calculate dangerous commutators...

Murase, Kenta

2015-01-01

51

Gravitational F-terms through anomaly equations and deformed chiral rings

International Nuclear Information System (INIS)

We study effective gravitational F-terms, obtained by integrating an U(N) adjoint chiral superfield ? coupled to the N = 1 gauge chiral superfield W? and supergravity, to arbitrary orders in the gravitational background. The latter includes in addition to the N = 1 Weyl superfield G???, the self-dual graviphoton field strength F?? of the parent, broken N = 2 theory. We first study the chiral ring relations resulting from the above non-standard gravitational background and find agreement, for gauge invariant operators, with those obtained from the dual closed string side via Bianchi identities for N = 2 supergravity coupled to vector multiplets. We then derive generalized anomaly equations for connected correlators on the gauge theory side, which allow us to solve for the basic one-point function 2/(z - ?)> to all orders in F2. By generalizing the matrix model loop equation to the generating functional of connected correlators of resolvents, we prove that the gauge theory result coincides with the genus expansion of the associated matrix model, after identifying the expansion parameters on the two sides. (author)

52

Triangle anomaly in the light-cone gauge

Energy Technology Data Exchange (ETDEWEB)

It is shown that the triangle anomaly can be evaluated in the light-cone gauge and that the result obtained is consistent with the usual covariant one. We use two different procedures: (i) Eliminating the non-physical fields from the covariant anomalous Ward identity. (ii) Carrying out a chiral transformation on the light-cone lagrangian. The use of both dimensional and Pauli-Villars regularisations are discussed.

Capper, D.M.; Jones, D.R.T.; Litvak, M.J.

1986-09-01

53

The triangle anomaly in the light-cone gauge

It is shown that the triangle anomaly can be evaluated in the light-cone gauge and that the result obtained is consistent with the usual covariant one. We use two different procedures: (i) Eliminating the nonphysical fields from the covariant anomalous Ward identity. (ii) Carrying out a chiral transformation on the light-cone Lagrangian. The use of both dimensional and Pauli-Villars regularisations are discussed.

Capper, D. M.; Jones, D. R. T.; Litvak, M. J.

1986-06-01

54

The triangle anomaly in the light-cone gauge

International Nuclear Information System (INIS)

It is shown that the triangle anomaly can be evaluated in the light-cone gauge and that the result obtained is consistent with the usual covariant one. We use two different procedures: (i) Eliminating the non-physical fields from the covariant anomalous Ward identity. (ii) Carrying out a chiral transformation on the light-cone lagrangian. The use of both dimensional and Pauli-Villars regularisations are discussed. (orig.)

55

Observation of the Chern-Simons gauge anomaly

Topological Quantum Field Theories (TQFTs) are powerful tools to describe universal features of topological orders. A hallmark example of a TQFT is the 2+1 D Chern-Simons (CS) theory which describes topological properties of both integer and fractional quantum Hall effects. The gauge invariant form of the CS theory with boundaries, encompassing both edge and bulk terms, provides an unambiguous way to relate bulk topological invariants to the edge dynamics. This bulk-edge correspondence is manifested as a gauge anomaly of the chiral dynamics at the edge, and provides a direct insight into the bulk topological order. Such an anomaly has never been directly observed in an experiment. In this work, we experimentally implement the integer quantum Hall model in a photonic system, described by the corresponding CS theory. By selectively manipulating and probing the edge, we exploit the gauge anomaly of the CS theory, for the first time. The associated spectral edge flow allows us to unambiguously measure topological...

Mittal, Sunil; Fan, Jingyun; Vaezi, Abolhassan; Hafezi, Mohammad

2015-01-01

56

Gravitation, gauge theories and differential geometry

International Nuclear Information System (INIS)

The purpose of this article is to outline various mathematical ideas, methods, and results, primarily from differential geometry and topology, and to show where they can be applied to Yang-Mills gauge theories and Einstein's theory of gravitation.We have several goals in mind. The first is to convey to physicists the bases for many mathematical concepts by using intuitive arguments while avoiding the detailed formality of most textbooks. Although a variety of mathematical theorems will be stated, we will generally give simple examples motivating the results instead of presenting abstract proofs. Another goal is to list a wide variety of mathematical terminology and results in a format which allows easy reference. The reader then has the option of supplementing the descriptions given here by consulting standard mathematical references and articles such as those listed in the bibliography. Finally, we intend this article to serve the dual purpose of acquainting mathematicians with some basic physical concepts which have mathematical ramifications; physical problems have often stimuladed new directions in mathematical thought. (orig./WL)

57

Supersymmetry, quantum gauge anomalies and generalized Chern-Simons terms in chiral gauge theory

International Nuclear Information System (INIS)

The purpose of this thesis is to investigate the interplay of anomaly cancellation and generalized Chern-Simons terms in four-dimensional chiral gauge theory. We start with a detailed discussion of generalized Chern-Simons terms with the canellation of anomalies via the Green-Schwarz mechanism. With this at hand, we investigate the situation in general N=1 supersymmetric field theories with generalized Chern-Simons terms. Two simple consistency conditions are shown to encode strong constraints on the allowed anomalies for different types of gauge groups. In one major part of this thesis we are going to display to what extent one has to modify the existing formalism in order to allow for the cancellation of quantum gauge anomalies via the Green-Schwarz mechanism. At the end of this thesis we comment on a puzzle in the literature on supersymmetric field theories with massive tensor fields. The potential contains a term that does not arise from eliminating an auxiliary field. We clarify the origin of this term and display the relation to standard D-term potential. In an appendix it is explicitly shown how these low energy effective actions might be connected to the formulation of four-dimensional gauge theories discussed at earlier stages of this thesis. (orig.)

58

Supersymmetry, quantum gauge anomalies and generalized Chern-Simons terms in chiral gauge theory

Energy Technology Data Exchange (ETDEWEB)

The purpose of this thesis is to investigate the interplay of anomaly cancellation and generalized Chern-Simons terms in four-dimensional chiral gauge theory. We start with a detailed discussion of generalized Chern-Simons terms with the canellation of anomalies via the Green-Schwarz mechanism. With this at hand, we investigate the situation in general N=1 supersymmetric field theories with generalized Chern-Simons terms. Two simple consistency conditions are shown to encode strong constraints on the allowed anomalies for different types of gauge groups. In one major part of this thesis we are going to display to what extent one has to modify the existing formalism in order to allow for the cancellation of quantum gauge anomalies via the Green-Schwarz mechanism. At the end of this thesis we comment on a puzzle in the literature on supersymmetric field theories with massive tensor fields. The potential contains a term that does not arise from eliminating an auxiliary field. We clarify the origin of this term and display the relation to standard D-term potential. In an appendix it is explicitly shown how these low energy effective actions might be connected to the formulation of four-dimensional gauge theories discussed at earlier stages of this thesis. (orig.)

Schmidt, Torsten

2009-05-13

59

Gauge Approach to Gravitation and Regular Big Bang Theory

Field theoretical scheme of regular Big Bang in 4-dimensional physical space-time, built in the framework of gauge approach to gravitation, is discussed. Regular bouncing character of homogeneous isotropic cosmological models is ensured by gravitational repulsion effect at extreme conditions without quantum gravitational corrections. The most general properties of regular inflationary cosmological models are examined. Developing theory is valid, if energy density of gravitat...

Minkevich, A. V.

2005-01-01

60

NS5-branes in IIA supergravity and gravitational anomalies

We construct a gravitational-anomaly-free effective action for the coupled system of IIA D=10 dynamical supergravity interacting with an NS5-brane. The NS5-brane is considered as elementary in that the associated current is a delta-function supported on its worldvolume. Our approach is based on a Chern-kernel which encodes the singularities of the three-form field strength near the brane in an SO(4)-invariant way and provides a solution for its Bianchi identity in terms of a two-form potential. A dimensional reduction of the recently constructed anomaly-free effective action for an elementary M5-brane in D=11 is seen to reproduce our ten-dimensional action. The Chern-kernel approach provides in particular a concrete realization of the anomaly cancellation mechanism envisaged by Witten.

Cariglia, M; Cariglia, Marco; Lechner, Kurt

2002-01-01

61

Hawking radiation of a vector field and gravitational anomalies

International Nuclear Information System (INIS)

Recently, the relation between Hawking radiation and gravitational anomalies has been used to estimate the flux of Hawking radiation for a large class of black objects. In this paper, we extend the formalism, originally proposed by Robinson and Wilczek, to the Hawking radiation of vector particles (photons). It is explicitly shown, with the Hamiltonian formalism, that the theory of an electromagnetic field on d-dimensional spherical black holes reduces to one of an infinite number of massive complex scalar fields on 2-dimensional spacetime, for which the usual anomaly-cancellation method is available. It is found that the total energy emitted from the horizon for the electromagnetic field is just (d-2) times that for a scalar field. The results support the picture that Hawking radiation can be regarded as an anomaly eliminator on horizons. Possible extensions and applications of the analysis are discussed

62

Gravitational counterterms in an axial gauge

International Nuclear Information System (INIS)

All the counterterms of quantum Einstein gravity are calculated up to bilinear terms and one-loop order in an axial gauge as a sum of gauge-invariant and the Becchi-Rouet-Stora-invariant terms. Contrary to the de Donder gauge condition, ten out of thirty-three coefficients for counterterms remain undetermined in this gauge. Some relations among the counterterms, which satisfy the BRS invariance, are implicitly obtained in the course of the calculations

63

Addressing the LHC flavour anomalies with horizontal gauge symmetries

We study the impact of an additional $U(1)'$ gauge symmetry with flavour-dependent charges for quarks and leptons on the LHC flavour anomalies observed in $B \\to K^* \\mu^+\\mu^-$, $R(K) = B \\to K \\mu^+\\mu^-/B \\to K e^+e^-$ and $h \\to \\mu\\tau$. In its minimal version with two scalar doublets the resulting model naturally explains the deviations from the Standard Model observed in $B \\to K^* \\mu^+\\mu^-$ and $R(K)$. The CMS access in $h \\to \\mu\\tau$ can be explained by introducing a third scalar doublet, which gives rise to a prediction for $\\tau \\to 3\\mu$. We investigate constraints from flavour observables and direct LHC searches for $pp \\to Z' \\to \\mu^+\\mu^-$. Our model successfully generates the measured fermion-mixing matrices and does not require vector-like fermions, unlike previous attempts to explain these anomalies.

Crivellin, Andreas; Heeck, Julian

2015-01-01

64

Gauge field, strings, solitons, anomalies and the speed of life

It's been said that "mathematics is biology's next microscope, only better; biology is mathematics' next physics, only better". Here we aim for something even better. We try to combine mathematical physics and biology into a picoscope of life. For this we merge techniques which have been introduced and developed in modern mathematical physics, largely by Ludvig Faddeev to describe objects such as solitons and Higgs and to explain phenomena such as anomalies in gauge fields. We propose a synthesis that can help to resolve the protein folding problem, one of the most important conundrums in all of science. We apply the concept of gauge invariance to scrutinize the extrinsic geometry of strings in three dimensional space. We evoke general principles of symmetry in combination with Wilsonian universality and derive an essentially unique Landau-Ginzburg energy that describes the dynamics of a generic string-like configuration in the far infrared. We observe that the energy supports topological solitons, that perta...

Niemi, Antti J

2014-01-01

65

Gauge fields, strings, solitons, anomalies, and the speed of life

Joel Cohen proposed that "mathematics is biology's next microscope, only better; biology is mathematics' next physics, only better." Here, we aim for something even better. We try to combine mathematical physics and biology into a picoscope of life. For this, we merge techniques that were introduced and developed in modern mathematical physics, largely by Ludvig Faddeev, to describe objects such as solitons and Higgs and to explain phenomena such as anomalies in gauge fields. We propose a synthesis that can help to resolve the protein folding problem, one of the most important conundrums in all of science. We apply the concept of gauge invariance to scrutinize the extrinsic geometry of strings in three-dimensional space. We evoke general principles of symmetry in combination with Wilsonian universality and derive an essentially unique Landau-Ginzburg energy that describes the dynamics of a generic stringlike configuration in the far infrared. We observe that the energy supports topological solitons that relate to an anomaly similarly to how a string is framed around its inflection points. We explain how the solitons operate as modular building blocks from which folded proteins are composed. We describe crystallographic protein structures by multisolitons with experimental precision and investigate the nonequilibrium dynamics of proteins under temperature variations. We simulate the folding process of a protein at in vivo speed and with close to picoscale accuracy using a standard laptop computer. With picobiology as next pursuit of mathematical physics, things can only get better.

Niemi, A. J.

2014-10-01

66

Searching for $Z^{'}$ Gauge Boson in an Anomaly-Free U(1)$'$ Gauge Family Model

We study a simple ultraviolet(UV) complete and anomaly free $Z'$ model based on a U$(1)'$ gauge family symmetry without introducing extra fermions beyond the standard model. The U$(1)'$ group is diagonal in the three family space in which the U(1)$'$ charges of the first and second families are the same but different from those of the third family. After spontaneous symmetry breaking and rotating to the mass eigenstates of quarks and leptons, there exist in general both flav...

Liu, Jin-yan; Tang, Yong; Wu, Yue-liang

2011-01-01

67

Effective QED actions: Representations, gauge invariance, anomalies, and mass expansions

International Nuclear Information System (INIS)

We analyze and give explicit representations for the effective Abelian vector gauge field actions generated by charged fermions with particular attention to the thermal regime in odd dimensions, where spectral asymmetry can be present. We show, through ?-function regularization, that both small and large gauge invariances are preserved at any temperature and for any number of fermions at the usual price of anomalies: helicity (parity) invariance will be lost in even (odd) dimensions, and in the latter even at zero mass. Gauge invariance dictates a very general 'Fourier' representation of the action in terms of the holonomies that carry the novel, large gauge-invariant, information. We show that large (unlike small) transformations and hence their Ward identities are not perturbative order-preserving, and clarify the role of (properly redefined) Chern-Simons terms in this context. From a powerful representation of the action in terms of massless heat kernels, we are able to obtain rigorous gauge-invariant expansions, for both small and large fermion masses, of its separate parity even and odd parts in arbitrary dimension. The representation also displays both the nonperturbative origin of a finite renormalization ambiguity and its physical resolution by requiring decoupling at infinite mass. Finally, we illustrate these general results by explicit computation of the effective action for some physical examples of field configurations in the three-dimensional case, whertions in the three-dimensional case, where our conclusions on finite temperature effects may have physical relevance. Non-Abelian results will be presented separately. copyright 1998 The American Physical Society

68

Branes as solutions of gauge theories in gravitational field

Energy Technology Data Exchange (ETDEWEB)

The idea of the Gauss map is unified with the concept of branes as hypersurfaces embedded into D-dimensional Minkowski space. The map introduces new generalized coordinates of branes alternative to their world vectors x and identified with the gauge and other massless fields. In these coordinates the Dirac p-branes realize extremals of the Euler-Lagrange equations of motion of a (p + 1)- dimensional SO(D-p-1) gauge-invariant action in a gravitational background. (orig.)

Zheltukhin, A.A. [Kharkov Institute of Physics and Technology, Kharkov (Ukraine); KTH Royal Institute of Technology and Stockholm University, Nordita, the Nordic Institute for Theoretical Physics, Stockholm (Sweden)

2014-09-15

69

Branes as solutions of gauge theories in gravitational field

International Nuclear Information System (INIS)

The idea of the Gauss map is unified with the concept of branes as hypersurfaces embedded into D-dimensional Minkowski space. The map introduces new generalized coordinates of branes alternative to their world vectors x and identified with the gauge and other massless fields. In these coordinates the Dirac p-branes realize extremals of the Euler-Lagrange equations of motion of a (p + 1)- dimensional SO(D-p-1) gauge-invariant action in a gravitational background. (orig.)

70

Anomaly-free gauged U(1)' in local supersymmetry and baryon-number violation

International Nuclear Information System (INIS)

The supersymmetric extension of the standard model suffers from a problem of baryon-number violation. Discrete (and global) symmetries introduced to protect the proton are unstable under gravitational effects. We add a gauged U(1)X to the standard model gauge group GSM and require it to be anomaly-free. As new (chiral) superfields we only allow GSM-singlets in order to maintain the good unification predictions. We find the most general set of solutions for the rational singlet charges. We embed our models in local supersymmetry and study the breaking of supersymmetry and U(1)X to determine MX. We determine the full non-renormalizable and gauge invariant Lagrangian for the different solutions. We expect any effective theory to contain baryon-and lepton-number violating terms of dimension four suppressed by powers of MX/MPl. The power is predicted by the U(1)X charges. We find consistency with the experimental bounds on the proton lifetime and on the neutrino masses. We also expect all supersymmetric models to have an unstable but longlived lightest supersymmetric particle. Consistency with underground experiments on upward going muons leads to stricter constraints than the proton decay experiments. These are barely satisfied. (orig.)

71

The UV and IR origin of non-Abelian chiral gauge anomalies on noncommutative Minkowski spacetime

International Nuclear Information System (INIS)

We discuss both the UV and IR origins of the one-loop triangle gauge anomalies for noncommutative non-Abelian chiral gauge theories with fundamental, adjoint and bi-fundamental fermions for U(N) groups. We find that gauge anomalies only originate from planar triangle diagrams, the nonplanar triangle contributions giving rise to no breaking of the Ward identities. Generally speaking, theories with fundamental and bi-fundamental chiral matter are anomalous. Theories with only adjoint chiral fermions are anomaly free. (author)

72

On the interpretation of gravitational corrections to gauge couplings

Energy Technology Data Exchange (ETDEWEB)

Several recent papers discuss gravitational corrections to gauge couplings that depend quadratically on the energy. In the framework of the background-field approach, these correspond in general to adding to the effective action terms quadratic in the field strength but with higher-order space-time derivatives. We observe that such terms can be removed by appropriate local field redefinitions, and do not contribute to physical scattering-matrix elements. We illustrate this observation in the context of open string theory, where the effective action includes, among other terms, the well-known Born-Infeld form of non-linear electrodynamics. We conclude that the quadratically energy-dependent gravitational corrections are not physical in the sense of contributing to the running of a physically-measurable gauge coupling, or of unifying couplings as in string theory.

Ellis, John [Theoretical Particle Physics and Cosmology Group, Department of Physics, King' s College London, Strand, London WC2R 2LS (United Kingdom); Theory Division, Department of Physics, CERN, CH-1211 Geneva 23 (Switzerland); Mavromatos, Nick E., E-mail: nikolaos.mavromatos@kcl.ac.uk [Theoretical Particle Physics and Cosmology Group, Department of Physics, King' s College London, Strand, London WC2R 2LS (United Kingdom); Theory Division, Department of Physics, CERN, CH-1211 Geneva 23 (Switzerland)

2012-05-01

73

International Nuclear Information System (INIS)

A new type of anomaly is discussed that afflicts certain non-linear sigma models with fermions. This anomaly is similar to the ordinary gauge and gravitational anomalies since it reflects a topological obstruction to the reparametrization invariance of the quantum effective action. Nonlinear sigma models are constructed based on homogeneous spaces G/H. Anomalies arising when the fermions are chiral are shown to be cancelled sometimes by Chern-Simons terms. Nonlinear sigma models are considered based on general Riemannian manifolds. 9 refs

74

A Gauge-theoretical Treatment of the Gravitational Field: Classical

In the geometrodynamical setting of general relativity one is concerned mainly with Riemannian metrics over a manifold $M$. We show that for the space Riem$(M)$, we have a natural principal fiber bundle (PFB) structure. This construction makes the gravitational field amenable to exactly the same gauge-theoretic treatment given in [Littlejohn] where it is used to separate rotational and vibrational degrees of freedom of $n$-particle systems, both classically and quantum mechanically. Furthermore, we show how the gauge connection in this PFB setting can be seen as a realization of Mach's Principle of Relative Motion, in accordance with Barbour's et al work on timeless gravitational theories. We show Barbour's reconstruction of GR is obtained by requiring the connection to be the one induced by the deWitt metric in Riem$(M)$. As a simple application of the gauge theory, we put the ADM lagrangian in a Kaluza-Klein context, and from conservation of charge we derive an interesting condition on the three-dimensional...

Gomes, Henrique

2008-01-01

75

Translational anomaly in chiral gauge theories on a torus and the overlap formalism

International Nuclear Information System (INIS)

We point out that a fermion determinant of a chiral gauge theory on a 2D torus has a phase ambiguity proportional to the Polyakov loops along the boundaries, which can be reproduced by the overlap formalism. We show that the requirement on the fermion determinant that a singularity in the gauge field can be absorbed by a change of the boundary condition for the fermions, is not compatible with translational invariance in general. As a consequence,the gauge anomaly for singular gauge transformations discovered by Narayanan-Neuberger actually exists in any 2D U(1) chiral gauge theory unless the theory is vector-like. We argue that the gauge anomaly is peculiar to the overlap formalism with the Wigner-Brillouin phase choice and that it is not necessarily a property required in the continuum. We also generalize our results to any even dimension. (author)

76

Dilaton-dependent ?' corrections in gauge theory of gravitation

International Nuclear Information System (INIS)

Some solutions without singularities to an effective action derived from low-energy heterotic string theory with dilaton, ?' corrections and a potential for the dilaton are presented in a de-Sitter gauge theory of gravitation over a spherical symmetric Minkowski space-time. The higher derivative terms of ?' corrections are constructed so that they vanish when the spacetime is de-Sitter in the equivalent dilaton gravity. With a particular choice of the gauge fields and of the action with ?' expansion, which is typical of strings and disappears in the point-like limit, the field equations are derived. A singularity free solution, presented in this paper, is that which at late times is asymptotically Minkowski and the dilaton is frozen and if t ? 0 then the universe enters a de-Sitter phase. The calculations are performed using an analytical program conceived in GRTensorII for Maple 8. (author)

77

Parity anomaly in D=3 Chern-Simons gauge theory

International Nuclear Information System (INIS)

Ultraviolet divergences are calcelled in the effective action of the D=3 Chern-Simons gauge theory but regularization is needed. It is impossible to introduce gauge invariant regularization and conserve the parity of the classical action. As a result, in the limit when regularization is moved the finite contribution to the effective action induced by parity violating regulators remains. 18 refs

78

On the problem of axial anomaly in supersymmetric gauge theories

International Nuclear Information System (INIS)

The explicit relation is found between the axial current obeying the Adler-Bardeen theorem and the supersymmetric one belonging to a supermultiplet. It is shown that the axial and superconformal anomalies are consistent in all orders of perturbation theory

79

Chiral anomalies in higher-derivative supersymmetric 6D gauge theories

International Nuclear Information System (INIS)

We show that the recently constructed higher-derivative 6D SYM theory involves internal chiral anomaly breaking gauge invariance. The anomaly is cancelled when adding to the theory an adjoint matter hyper-multiplet. One shows that as the effective charge grows at high energies, the theories are not consistently defined nonperturbatively. Constructing a nontrivial 6D theory that would be internally consistent both perturbatively and nonperturbatively remains a major challenge. (author)

80

The structure of the anomalies of gauge theories in the causal approach

International Nuclear Information System (INIS)

We consider the gauge invariance of the standard Yang-Mills model in the framework of the causal approach of Epstein-Glaser and Scharf and determine the generic form of the anomalies. The method used is based on the Epstein-Glaser approach to renormalization theory. In the case of quantum electrodynamics we obtain quite easily the absence of anomalies in all orders. (author)

81

Supersymmetry anomalies and some aspects of renormalization

International Nuclear Information System (INIS)

We show how the S-matrix elements avoid the problem of supersymmetry breaking by the gauge fixing and ghost terms for renormalization in the Wess-Zumino gauge. Possible origins of supersymmetry anomalies are discussed. Gauge and gravitational anomalies induce a supersymmetry anomaly which has two distinct terms, one of which is gauge invariant. We give the expression for the noninvariant term for 2n-dimensional spacetime and for the invariant part in four dimensions. This anomaly, although cohomologically nontrivial, is still consistent with the result that in superspace no supersymmetry anomaly is generated. (orig.)

82

Non-commutative differential calculus and the axial anomaly in Abelian lattice gauge theories

International Nuclear Information System (INIS)

The axial anomaly in lattice gauge theories has a topological nature when the Dirac operator satisfies the Ginsparg-Wilson relation. We study the axial anomaly in Abelian gauge theories on an infinite hypercubic lattice by utilizing cohomological arguments. The crucial tool in our approach is the non-commutative differential calculus (NCDC) which makes the Leibniz rule of exterior derivatives valid on the lattice. The topological nature of the 'Chern character' on the lattice becomes manifest in the context of NCDC. Our result provides an algebraic proof of Luescher's theorem for a four-dimensional lattice and its generalization to arbitrary dimensions

83

Holomorphy, Rescaling Anomalies and Exact ? Functions in Supersymmetric Gauge Theories

International Nuclear Information System (INIS)

There have been known exact'' ? functions for the gauge coupling in N=1 supersymmetric gauge theories, the so-called NSVZ ? functions. Shifman and Vainshtein (SV) further related these ? functions to the exact 1-loop running of the Wilsonian'' Gauge coupling. All these results, however, remain somewhat mysterious. We attempt to clarify these issues by presenting new perspectives on the NSVZ ? function. Our interpretation of the results is somewhat different than the one given by SV, having nothing to do with the distinction between Wilsonian'' and 1PI'' effective actions. Throughout we work in the context of the Wilsonian Renormalization Group; namely, as the cutoff of the theory is changed from M to M', we determine the appropriate changes in the bare couplings needed to keep the low energy physics fixed. The entire analysis is therefore free of infrared subtleties. When the bare Lagrangian given at the cutoff is manifestly holomorphic in the gauge coupling, we show that the required change in the holomorphic gauge coupling is exhausted at 1-loop to all orders of perturbation theory, and even non-perturbatively in some cases. On the other hand, when the bare Lagrangian has canonically normalized kinetic terms, we find that the required change in the gauge coupling is given by the NSVZ ? function. The higher order contributions in the NSVZ ? function are due to anomalous Jacobians under the rescaling of the fields doneder the rescaling of the fields done in passing from holomorphic to canonical normalization. We also give prescriptions for regularizing certain N=1 theories with an ultraviolet cutoff M preserving manifest holomorphy, starting from finite N=4 and N=2 theories. It is then in principle possible to check the validity of the exact ? function by higher order calculations in these theories. (author)

84

Odd decays from even anomalies: Gauge mediation signatures without supersymmetry

International Nuclear Information System (INIS)

We analyze the theory and phenomenology of anomalous global chiral symmetries in the presence of an extra dimension. We propose a simple extension of the standard model in 5D whose signatures closely resemble those of supersymmetry with gauge mediation, and we suggest a novel scalar dark matter candidate.

85

Anomaly free U(1) chiral gauge theories on a two-dimensional torus

International Nuclear Information System (INIS)

We consider anomaly free combinations of chiral fermions coupled to U(1) gauge fields on a 2D torus first in the continuum and then on the lattice in the overlap formulation. Both in the continuum and on the lattice, when the background consists of sufficiently large constant gauge potentials, the action induced by the fermions varies significantly under certain singular gauge transformations. ''Ruling away'' such discontinuities cannot be justified in the continuum framework and does not naturally fit on the lattice. Complete gauge invariance in the continuum can be restored in some models by choosing special boundary conditions for the fermions. Evidence is presented that gauge averaging the overlap phases in these models produces correct continuum results. (orig.)

86

Adler-Bardeen theorem and manifest anomaly cancellation to all orders in gauge theories

Energy Technology Data Exchange (ETDEWEB)

We reconsider the Adler-Bardeen theorem for the cancellation of gauge anomalies to all orders, when they vanish at one loop. Using the Batalin-Vilkovisky formalism and combining the dimensional-regularization technique with the higher-derivative gauge invariant regularization, we prove the theorem in the most general perturbatively unitary renormalizable gauge theories coupled to matter in four dimensions, and we identify the subtraction scheme where anomaly cancellation to all orders is manifest, namely no subtractions of finite local counterterms are required from two loops onwards. Our approach is based on an order-by-order analysis of renormalization, and, differently from most derivations existing in the literature, does not make use of arguments based on the properties of the renormalization group. As a consequence, the proof we give also applies to conformal field theories and finite theories. (orig.)

Anselmi, Damiano [Pisa Univ. (Italy). Dipt. di Fisica ' ' Enrico Fermi' '

2014-10-15

87

Adler-Bardeen theorem and manifest anomaly cancellation to all orders in gauge theories

International Nuclear Information System (INIS)

We reconsider the Adler-Bardeen theorem for the cancellation of gauge anomalies to all orders, when they vanish at one loop. Using the Batalin-Vilkovisky formalism and combining the dimensional-regularization technique with the higher-derivative gauge invariant regularization, we prove the theorem in the most general perturbatively unitary renormalizable gauge theories coupled to matter in four dimensions, and we identify the subtraction scheme where anomaly cancellation to all orders is manifest, namely no subtractions of finite local counterterms are required from two loops onwards. Our approach is based on an order-by-order analysis of renormalization, and, differently from most derivations existing in the literature, does not make use of arguments based on the properties of the renormalization group. As a consequence, the proof we give also applies to conformal field theories and finite theories. (orig.)

88

Gravitational F-terms through anomaly equations and deformed chiral rings

We study effective gravitational F-terms, obtained by integrating an $U(N)$ adjoint chiral superfield $\\Phi$ coupled to the ${\\cal N}=1$ gauge chiral superfield $W_\\alpha$ and supergravity, to arbitrary orders in the gravitational background. The latter includes in addition to the ${\\cal N}=1$ Weyl superfield $G_{\\alpha\\beta\\gamma}$, the self-dual graviphoton field strength $F_{\\alpha\\beta}$ of the parent, broken ${\\cal N}=2$ theory. We first study the chiral ring relations ...

Alday, Lf; Cirafici, M.; David, Jr; Gava, E.; Narain, Ks

2003-01-01

89

Stochastic quantization and gauge-fixing of the linearized gravitational field

International Nuclear Information System (INIS)

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)

90

Non-perturbative scale anomaly and composite operators in gauge field theories

International Nuclear Information System (INIS)

In non-asymptotically free gauge theories with a non-trivial ultraviolet fixed point, scale symmetry breaking (the scale anomaly) caused by the non-perturbative 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 phase of the theory to which it relates. The hypothesis about the soft behaviour at small distances of composite operators in such theories is confirmed. (orig.)

91

New operator solution of the Schwinger model in a covariant gauge and axial anomaly

Massless QED(1+1) - the Schwinger model - is studied in a covariant gauge. The main new ingredient is an operator solution of the Dirac equation expressed directly in terms of the fields present in the Lagrangian. This allows us to study in detail the residual symmetry of the covariant gauge. For comparison, we analyze first an analogous solution in the Thirring-Wess model and its implication for the axial anomaly arising from the necessity to correctly define products of fermion operators via point-splitting. In the Schwinger model, one has to define the currents in a gauge invariant (GI) way. Certain problems with their usual derivation are identified that obscure the origin of the massive vector boson. We show how to define the truly GI interacting currents, reformulate the theory in a finite volume and clarify role of the gauge zero mode in the axial anomaly and in the Schwinger mechanism. A transformation to the Coulomb gauge representation is suggested along with ideas about how to correctly obtain othe...

Martinovic, Lubomir

2013-01-01

92

International Nuclear Information System (INIS)

We show that certain one-loop corrections to superstring effective four-dimensional lagrangians, involving non-harmonic field-dependent renormalization of gauge couplings, can be consistently written in a standard N=1 supergravity form, preserving target-space duality. The preservation of target-space duality is due both to a four-dimensional Green-Schwarz mechanism and to local terms, coming from non-local chiral superfields, originated by mixed gauge-?-model anomaly diagrams. In some models, the Green-Schwarz mechanism is sufficient to achieve complete anomaly cancellation. In more general models automorphic functions, generated by the integration over the heavy string modes, are required to preserve target-space duality. (orig.)

93

Gauge-invariant definition of gravitational radiation in Robertson-Walker cosmologies

International Nuclear Information System (INIS)

Gauge-invariant quantities are introduced which relate directly to the ideal fluid perturbations in Robertson-Walker backgrounds. It is shown how the vanishing of these gauge invariants is equivalent to the definition of purely radiative perturbations found in some early works. If one imposes a regularity condition, then the vanishing of just four gauge invariants is sufficient to define the condition of no perturbation of matter. The latter result is used to clarify the relationship to Hawking's definition of gravitational radiation

94

Gauged R-symmetry and its anomalies in 4D N=1 supergravity and phenomenological implications

We consider a class of models with gauged U(1) R symmetry in 4D N=1 super-gravity that have, at the classical level, a metastable ground state, an infinitesimally small (tunable) positive cosmological constant and a TeV gravitino mass. We analyse if these properties are maintained under the addition of visible sector (MSSM-like) and hidden sector state(s), where the latter may be needed for quantum consistency. We then discuss the anomaly cancellation conditions in supergravity as derived by Freedman, Elvang and Körs and apply their results to the special case of a U(1) R symmetry, in the presence of the Fayet-Iliopoulos term ( ?) and Green-Schwarz mechanism(s). We investigate the relation of these anomaly cancellation conditions to the "naive" field theory approach in global SUSY, in which case U(1) R cannot even be gauged. We show the two approaches give similar conditions. Their induced constraints at the phenomenological level, on the above models, remain strong even if one lifted the GUT-like conditions for the MSSM gauge couplings. In an anomaly-free model, a tunable, TeV-scale gravitino mass may remain possible provided that the U(1) R charges of additional hidden sector fermions (constrained by the cubic anomaly alone) do not conflict with the related values of U(1) R charges of their scalar superpartners, constrained by existence of a stable ground state. This issue may be bypassed by tuning instead the coefficients of the Kahler connection anomalies ( b K , b CK ).

Antoniadis, I.; Ghilencea, D. M.; Knoops, R.

2015-02-01

95

The principal goal of the physics of the fundamental interactions is to provide a consistent description of the nature of the subnuclear forces, which manifest in our universe, together with the gravitational force, in a unified framework. This attempt, which is far from being complete, is characterized by two milestones, the Standard Model of the elementary particles and the Einstein's theory of General Relativity. The coupling of a quantum field theory, such as the Standard Model, to a weak gravitational background provides significant information concerning the coupling of matter to gravity and allows to study in a systematic way the origin of the conformal anomaly. For this reason, the computation of correlation functions in a weak gravitational background is of remarkable interest and the consequences of this analysis are also of phenomenological relevance. For instance, they concern the appearance in the spectrum of the theory of a composite state, the dilaton, which is identified, in perturbation theor...

Rose, Luigi Delle

2013-01-01

96

Response of test masses to gravitational waves in the local Lorentz gauge

International Nuclear Information System (INIS)

The local Lorentz gauge represents a natural coordinate frame for an observer to analyze the effect of gravitational waves on detectors, and has been widely used to describe the response of resonant bars. Its application to laser interferometers has thus far been restricted to the long-wavelength regime, in which the separation between the test masses is much less than the wavelength of the gravitational waves. In this paper we show that the local Lorentz gauge can be used for calculations of geodesic deviations of the masses even when their separation is comparable to or greater than the wavelength of the gravitational waves. We find that a complete description of the gravitational waves in this gauge requires taking into account three different effects: displacements of the test masses, the gravitational redshift of light propagating between the masses, and variations in the rates of stationary clocks, all of which are induced by the gravitational wave. Only when taken together do these three effects represent a quantity which is translationally invariant and which can be observed in experiments. This translationally invariant quantity is identical to the response function calculated in the transverse traceless gauge

97

Anomaly-free discrete gauge symmetries in Froggatt-Nielsen models

Energy Technology Data Exchange (ETDEWEB)

Discrete symmetries (DS) can forbid dangerous B- and L-violating operators in the supersymmetric Lagrangian. Due to the violation of global DSs by quantum gravity effects, the introduced DS should be a remnant of a spontaneously broken local gauge symmetry. Demanding anomaly freedom of the high-energy gauge theory, we determine all family-independent anomaly-free Z{sub N} symmetries which are consistent with the trilinear MSSM superpotential terms in Part I. We find one outstanding Z{sub 6} symmetry, proton hexality P{sub 6}, which prohibits all B- and L-violating operators up to dimension five, except for the Majorana neutrino mass terms LH{sub u}LH{sub u}. In Part II, we combine the idea that a DS should have a gauge origin with the scenario of Froggatt and Nielsen (FN). We construct concise U(1){sub X} FN models in which the Z{sub 3} symmetry baryon triality, B{sub 3}, arises from U(1){sub X} breaking. We choose this specific DGS because it allows for R-parity violating interactions; thus neutrino masses can be explained without introducing right-handed neutrinos. We find six phenomenologically viable B{sub 3}-conserving FN models. (orig.)

Luhn, C.

2006-05-15

98

Linearization stability of couples gravitational and gauge fields

International Nuclear Information System (INIS)

The work of Fischer, Marsden, and Moncrief on linearization stability of vacuum spacetimes is extended to the case of gravity coupled with a sourceless gauge field. (Linearization stability concerns the validity of first order perturbation theory. A nonlinear equation is said to be linearization stable when solutions of the linearized equation are tangent to curves of solutions of the original nonlinear equation.) For a spacetime with a compact Cauchy surface and a gauge field with matrix gauge group whose Lie algebra admits an adjoint action invariant nondegenerate metric, conditions for linearization stability of the coupled Einstein-Yang-Mills field equations are obtained. These conditions are sufficient conditions on the Cauchy surface and necessary and sufficient conditions on the spacetime. Roughly speaking, the results state that linearization stability can be guaranteed when the fields are not ''too symmetrical.'' Thus a generic solution, which lacks symmetry, is linearization stable. The proof of the main results uses the ellipticity of the adjoint operator to the linearized constraints, elliptic operator theory, and the implicit function theorem for Banach spaces. The spacetime results are most geometrically and concisely stated in terms of the principal fiber bundle formulation of gauge fields. Linearization instability, the kernel of the adjoint operator, and nontrivial infinitesimal symmetries on the bundle for the gravity and gauge fields are identified.e gravity and gauge fields are identified. Comparisons to related work, including the Atiyah-Hitchin-Singer work on the moduli space of self-dual gauge fields, are made

99

From Gauge Anomalies to Gerbes and Gerbal Representations: Group Cocycles in Quantum Theory

Directory of Open Access Journals (Sweden)

Full Text Available In this paper I shall discuss the role of group cohomology in quantum mechanics and quantum field theory. First, I recall how cocycles of degree 1 and 2 appear naturally in the context of gauge anomalies. Then we investigate how group cohomology of degree 3 comes from a prolongation problem for group extensions and we discuss its role in quantum field theory. Finally, we discuss a generalization to representation theory where a representation is replaced by a 1-cocycle or its prolongation by a circle, and point out how this type of situations come up in the quantization of Yang-Mills theory.

J. Mickelsson

2010-01-01

100

Anomaly, gauge and gaugino mediation in brane worlds with messenger matter.

Theories in which supersymmetry is broken on another brane, which is separated from the minimal supersymmetry standard model (MSSM) matter fields in an extra dimension, are attractive because they may solve the supersymmetric flavor problem. We consider the effects in such theories of new messenger fields with standard model gauge charges and with direct couplings to the supersymmetry breaking sector. The effect on the masses of the MSSM superpartners can be dramatic. In particular, the tachyonic slepton problem of anomaly mediation and the stable slepton problem of gaugino mediation can be cured. PMID:12059352

Nelson, Ann E; Weiner, Neal J

2002-06-10

101

Minimal anomaly-free chiral fermion sets and gauge coupling unification

We look for minimal chiral sets of fermions beyond the Standard Model that are anomaly-free and, simultaneously, vector-like particles with respect to colour SU(3) and electromagnetic U(1). We then study whether the addition of such particles to the Standard Model particle content allows for the unification of gauge couplings at a high energy scale, above $5.0 \\times 10^{15}$ GeV so as to be safely consistent with proton decay bounds. The possibility to have unification at the string scale is also considered. Inspired in grand unified theories, we also search for minimal chiral fermion sets that belong to SU(5) multiplets. Restricting to representations up to dimension 50, we show that some of these sets can lead to gauge unification at the GUT and/or string scales.

Cebola, Luis M; Felipe, R Gonzalez; Simoes, C

2014-01-01

102

The satellite gravitational gradiometry mission GOCE provides various products related to the Earth's gravitational field. One of these products is a global gravitational field model, i.e. representation of the Earth's gravitational field in terms of spherical harmonic coefficients. Such a model is used in realizing vertical reference frames in geodesy, exploring the interior of the Earth in geophysics and geology, studying the behavior of currents in oceanography, or discovering sea level rise and ice-melting in climatology. Numerous Earth's gravitational field representations have already been derived from GOCE. These representations differ according to the time span of GOCE measurements and the theoretical approach used in the harmonic analysis. To assess the quality of the GOCE models validation by independent knowledge of the gravitational field has to be performed. Global gravitational field models with limited spectral/spatial resolution are validated by terrestrial data. In this case, spectral inconsistency between the two sources of data has to be treated properly. An intuitive approach to perform the validation in a consistent way is offered by an adequate filtering. Transformation of the regional data into the spectral domain is performed firstly. Then a low-pass filter is applied to generate a smoothed version of the regional model with the same spectral content as the global GOCE model. Subsequently, the filtered signal is transformed back into the space domain where comparison with a GOCE geoid surface is performed. Despite its conceptual simplicity, the development of an optimal filtering procedure is still challenging. In this contribution we address some aspects of the filtering method. Firstly, a simulation study based on EGM2008 is performed to investigate the accuracy of the direct transformation from space to frequency domain and its inverse. Moreover, various mathematical filters are considered to filter out the short wavelengths. Secondly, the most accurate filtering procedure is applied in validation of real GOCE models. The validation experiment is performed with respect to gravity anomalies and geoid undulations over the territory of Scandinavia.

Sprlak, M.; Gerlach, C.; Pettersen, B. R.; Omang, O. C. D.

2012-04-01

103

Gravitational matter-antimatter asymmetry and four-dimensional Yang-Mills gauge symmetry

International Nuclear Information System (INIS)

A formulation of gravity based on the maximum four-dimensional Yang-Mills gauge symmetry is studied. The theory predicts that the gravitational force inside matter (fermions) is different from that inside antimatter. This difference could lead to the cosmic separation of matter and antimatter in the evolution of the universe. Moreover, a new gravitational long-range spin-force between two fermions is predicted, in addition to the usual Newtonian force. The geometrical foundation of such a gravitational theory is the Riemann-Cartan geometry, in which there is a torsion. The results of the theory for weak fields are consistent with previous experiments. (author)

104

Gravitational and gauge couplings in Chern-Simons fractional spin gravity

We propose an extension of Vasiliev's supertrace operation for the enveloping algebra of Wigner's deformed oscillator algebra to the fractional spin algebra given in arXiv:1312.5700. The resulting three-dimensional Chern-Simons theory unifies the Blencowe-Vasiliev higher spin gravity with fractional spin fields and internal gauge potentials. For integer or half-integer fractional spins, infinite dimensional ideals arise and decouple, leaving finite dimensional gauge algebras gl(2l+1) or gl(l|l+1) and various real forms thereof. We derive the relation between gravitational and internal gauge couplings.

Boulanger, Nicolas; Valenzuela, Mauricio

2015-01-01

105

Gauge theory duals of black hole - black string transitions of gravitational theories on a circle

We study the black hole - black string phase transitions of gravitational theories compactified on a circle using the holographic duality conjecture. The gauge theory duals of these theories are maximally supersymmetric and strongly coupled 1 + 1 dimensional SU(N) Yang-Mills theories compactified on a circle, in the large $N$ limit. We perform the strongly coupled finite temperature gauge theory calculations on a lattice, using the recently developed exact lattice supersymmetry methods based on topological twisting and orbifolding. The spatial Polyakov line serves as relevant order parameter of the confinement - deconfinement phase transitions in the gauge theory duals.

Catterall, Simon; Wiseman, Toby

2010-01-01

106

Two-loop chiral anomalies in open superstrings

International Nuclear Information System (INIS)

We partially analyze the two-loop box and hexagon chiral gauge anomalies in D = 6 and 10 dimensions for super-Yang-Mills theories. We apply these results to the SO(32) open superstring and show that the leading gauge anomaly vanishes at two-loop order while the subleading gauge anomalies, the mixed anomalies, and the subleading chiral gravitational anomalies may all be canceled with appropriate counterterms. To do this in field theory it is necessary to include a term B(TrF2)2 which is absent at one-loop order in the zero-slope limit of the SO(32) superstring

107

Moeller's tetrad theory of gravitation as a special case of Poincare gauge theory - a coincidence

International Nuclear Information System (INIS)

Moeller's tetrad theory of gravitation is included in Poincare gauge theory for a special choice of parameters. In both theories the conservation theorems are derived from the field equations. They have the same form as in Einstein's theory. The invariance properties of the field equations and questions concerning the interpretation and measurability of the tetrad coefficients are discussed. (author)

108

A Broken Gauge Approach to Gravitational Mass and Charge

We argue that a spontaneous breakdown of local Weyl invariance offers a mechanism in which gravitational interactions contribute to the generation of particle masses and their electric charge. The theory is formulated in terms of a spacetime geometry whose natural connection has both dynamic torsion and non-metricity. Its structure illuminates the role of dynamic scales used to determine measurable aspects of particle interactions and it predicts an additional neutral vector boson with electroweak properties.

Dereli, T

2002-01-01

109

International Nuclear Information System (INIS)

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.

110

Axial vacuum symmetry of the unified gauge theories with the gravitational mechanism of instability

International Nuclear Information System (INIS)

The problem of stable-state determination is considered in unified gauge theories involving gravitation. The gravitational fields are examined at a classical level. The self-consistent set of field equations is studied in the semiclassical approach. A new determination of stable states is given. If the conditions of the determination are not satisfied then the vacuum state may be metastable. For the case of axial symmetry the metastable Z-type states are shown to cancel if these states are symmetric. (author)

111

International Nuclear Information System (INIS)

The dynamics of metric perturbations is explored in the gravity theory with anomaly-induced quantum corrections. Our first purpose is to derive the equation for gravitational waves in this theory on the general homogeneous and isotropic background, and then verify the stability of such background with respect to metric perturbations. The problem under consideration has several interesting applications. Our first purpose is to explore the stability of the classical cosmological solutions in the theory with quantum effects taken into account. There is an interesting literature about stability of Minkowski and de Sitter spaces and here we extend the consideration also to the radiation and matter dominated cosmologies. Furthermore, we analyze the behavior of metric perturbations during inflationary period, in the stable phase of the Modified Starobinsky inflation

112

Gauge theory and gravitation: an approach to a fiber bundle formalism

International Nuclear Information System (INIS)

The thesis is composed of two different parts. A formal complete and rigorous mathematical part-of topics of differential manilfolds, exterior calculus, riemannian geometry, principal fiber bundle (p.f.) with connections and linear connections and a second part of application of this mathematical formalism concerning physical theories, particularly the Maxwell eletromagnetism (EM), gauge theory of Yang-Mills (Y-M), the GRT, and the gravitation theory of Einstein-Cartan. (E.C.)

113

Gauge-invariant gravitational wave modes in pre-big bang cosmology

International Nuclear Information System (INIS)

The t<0 branch of pre-big bang cosmological scenarios is subject to a gravitational wave instability. The unstable behaviour of tensor perturbations is derived in a very simple way in Hwang's covariant and gauge-invariant formalism developed for extended theories of gravity. A simple interpretation of this instability as the effect of an ''antifriction'' is given, and it is argued that a universe must eventually enter the expanding phase. (orig.)

114

Gauge-invariant gravitational wave modes in pre-big bang cosmology

Energy Technology Data Exchange (ETDEWEB)

The t<0 branch of pre-big bang cosmological scenarios is subject to a gravitational wave instability. The unstable behaviour of tensor perturbations is derived in a very simple way in Hwang's covariant and gauge-invariant formalism developed for extended theories of gravity. A simple interpretation of this instability as the effect of an ''antifriction'' is given, and it is argued that a universe must eventually enter the expanding phase. (orig.)

Faraoni, Valerio [Bishop' s University, Physics Department, Sherbrooke, Quebec (Canada)

2010-11-15

115

Gauge unification of basic forces particularly of gravitation with strong interactions

International Nuclear Information System (INIS)

Corresponding to the two known types of gauge theories, Yang-Mills with spin-one mediating particles and Einstein Weyl with spin-two mediating particles, it is speculated that two distinct gauge unifications of the basic forces appear to be taking place. One is the familiar Yang-Mills unification of weak and electromagnetic forces with the strong. The second is the less familiar gauge unification of gravitation with spin-two tensor-dominated aspects of strong interactions. It is proposed that there are strongly interacting spin-two strong gravitons obeying Einstein's equations, and their existence gives a clue to an understanding of the (partial) confinement of quarks, as well as of the concept of hadronic temperature, through the use of Schwarzschild de-Sitter-like partially confining solitonic solutions of the strong gravity Einstein equation

116

Numerical evolution of plane gravitational waves in the Friedrich-Nagy gauge

The first proof of well-posedness of an initial boundary value problem for the Einstein equations was given in 1999 by Friedrich and Nagy. They used a frame formalism with a particular gauge for formulating the equations. This `Friedrich-Nagy' (FN) gauge has never been implemented for use in numerical simulations before because it was deemed too complicated. In this paper we present an implementation of the FN gauge for systems with two commuting space-like Killing vectors. We investigate the numerical performance of this formulation for plane wave space-times, reproducing the well-known Khan-Penrose solution for colliding impulsive plane waves and exhibiting a gravitational wave `ping-pong'.

Frauendiener, Jörg

2014-01-01

117

Numerical evolution of plane gravitational waves in the Friedrich-Nagy gauge

The first proof of well posedness of an initial boundary value problem for the Einstein equations was given in 1999 by Friedrich and Nagy. They used a frame formalism with a particular gauge for formulating the equations. This "Friedrich-Nagy" gauge has never been implemented for use in numerical simulations before because it was deemed too complicated. In this paper we present an implementation of the Friedrich-Nagy gauge for systems with two commuting spacelike Killing vectors. We investigate the numerical performance of this formulation for plane wave space-times, reproducing the well-known Khan-Penrose solution for colliding impulsive plane waves and exhibiting a gravitational wave "ping-pong."

Frauendiener, Jörg; Stevens, Chris

2014-05-01

118

Chiral anomalies of bosonic fields in curved space-time

International Nuclear Information System (INIS)

In this paper it is shown that bosonic fields interacting with gravity possess chiral anomalies in complete analogy with fermions. The chiral current of photons is defined which is conserved in the classical limit. The triangle photonic graph in external gravitational field leads to the nonconservation of the chiral current. The photonic anomaly permits to calculate radiative corrections to the well-known fermionic chiral anomaly in gravitational field. The relation between the anomaly for vector fields and that of the gauge antisymmetric vector field is considered. The possible observational consequences of the anomaly are discussed

119

We introduce the Standard Model, list a large sector of the low energy data, and present extensions to the Standard Model including grand unification, supersymmetry, and orbifold extra dimensions. These foundations underly the research presented in this dissertation, which is from three separate projects. Texture models are Ansatze for the undiagonalized Yukawa matrices in which some of the matrix elements have been chosen to vanish. Recent precise measurements of sin 2beta from the B-factories (BABAR and BELLE) and a better known strange quark mass from lattice QCD make precision tests of predictive texture models possible. We show that in a set of these models, their maximal sin 2beta values rule them out at the 3sigma level. While at present sin 2beta and |Vub/Vcb| are equally good for testing N-zero texture models, in the near future the former will surpass the latter in constraining power. We construct a supersymmetric SO(10) x D3 grand unified model with an orbifold extra dimension S1/(Z2 x Z2'). The model uses 11 parameters to fit the 13 independent low energy observables of the charged fermion Yukawa matrices and predicts the values of two quark mass combinations, mu/mc and mdmsmb, to each be approximately 1sigma above their experimental values. The remaining observables are successfully fit at the 5% level. This model is shown to have a gauge anomaly on one of the fixed points and we discuss the alterations in field content necessary to repair it. Extra dimensional orbifold theories have gauge anomaly structures which are more complicated than those of Minkowski space. We review previous work done by von Gersdorff and Quiros to derive general expressions for orbifold gauge anomalies. These equations are applied to a supersymmetric 6D orbifold model with E6 gauge symmetry presented by Kobayashi, Raby, and Zhang in order to verify the gauge anomaly cancellations. From this illustration we conclude that the constraining power of orbifold gauge anomalies on the field content of the theory is about as great as the usual case in Minkowski space and depends highly on the gauge groups and number of dimensions present.

Schradin, Leslie J., III

120

Energy Technology Data Exchange (ETDEWEB)

We show that certain one-loop corrections to superstring effective four-dimensional lagrangians, involving non-harmonic field-dependent renormalization of gauge couplings, can be consistently written in a standard N=1 supergravity form, preserving target-space duality. The preservation of target-space duality is due both to a four-dimensional Green-Schwarz mechanism and to local terms, coming from non-local chiral superfields, originated by mixed gauge-{sigma}-model anomaly diagrams. In some models, the Green-Schwarz mechanism is sufficient to achieve complete anomaly cancellation. In more general models automorphic functions, generated by the integration over the heavy string modes, are required to preserve target-space duality. (orig.).

Derendinger, J.P.; Ferrara, S.; Kounnas, C.; Zwirner, F. (Theory Div., CERN, Geneva (Switzerland))

1992-03-16

121

We reexamine the gravitational collapse of rotating neutron stars to black holes by new 3 +1 numerical relativity simulations employing the Z4c formulation of Einstein equations, the moving puncture gauge conditions, and a conservative mesh refinement scheme for the general relativistic hydrodynamics. The end state of the collapse is compared to the vacuum spacetime resulting from the evolution of spinning puncture initial data. Using a local analysis for the metric fields, we demonstrate that the two spacetimes actually agree. Gravitational waveforms are analyzed in some detail. We connect the emission of radiation to the collapse dynamics using simplified spacetime diagrams, and discuss the similarity of the waveform structure with the one of black hole perturbation theory.

Dietrich, Tim; Bernuzzi, Sebastiano

2015-02-01

122

We reexamine the gravitational collapse of rotating neutron stars to black holes by new 3+1 numerical relativity simulations employing the Z4c formulation of Einstein equations, the moving puncture gauge conditions, and a conservative mesh refinement scheme or the general relativistic hydrodynamics. The end state of the collapse is compared to the vacuum spacetime resulting from the evolution of spinning puncture initial data. Using a local analysis for the metric fields, we demonstrate that the two spacetimes atually agree. Gravitational waveforms are analyzed in some detail. We connect the emission of radiation to the collapse dynamics using simplified spacetime diagrams, and discuss the similarity of the waveform structure with the one of black hole perturbation theory.

Dietrich, Tim

2014-01-01

123

About Lorentz Invariance and Gauge Symmetries: An Alternative Approach to Relativistic Gravitation

Directory of Open Access Journals (Sweden)

Full Text Available An alternative presentation of a relativistic theory of gravitation, equivalent to general relativity, is given. It is based upon the restriction of the Lorentz invariance of special relativity from a global invariance to a local one. The resulting expressions appear rather simple as we consider the transformations of a local set of pseudo-orthonormal coordinates and not the geometry of a 4-dimension hyper-surface described by a set of curvilinear coordinates. This is the major difference with the usual presentations of general relativity but that difference is purely formal. The usual approach is most adequate for describing the universe on a large scale in astrophysics and cosmology. The approach of this paper, derived from particle physics and focused on local reference frames, underlines the formal similarity between gravitation and the other interactions inasmuch as they are associated to the restriction of gauge symmetries from a global invariance to a local one.

Richard Bonneville

2014-11-01

124

Does the Neptunian system of satellites challenge a gravitational origin for the Pioneer anomaly?

If the Pioneer Anomaly was a genuine dynamical effect of gravitational origin, it should also affect the orbital motions of the solar system's bodies moving in the space regions in which the PA manifested itself in its presently known form, i.e. as a constant and uniform acceleration approximately directed towards the Sun with a non-zero magnitude (8.74+/-1.33) x 10^-10 m s^-2 after 20 au from the Sun. We preliminarily investigate its effects on the orbital motions of the Neptunian satellites Triton, Nereid and Proteus, located at about 30 au from the Sun, both analytically and numerically. The analytical calculations show that the PA-induced radial and transverse perturbations of Triton are of the order of a few km yr^-1, those of Nereid are about 10+/-100 km yr^-1, while Proteus experiences radial and transverse shifts of the order of 0.1 km yr^-1. The out-of-plane perturbations are negligible, apart from that of Nereid which amounts to about 20 km yr^-1. The corresponding orbital uncertainties obtained fro...

Iorio, Lorenzo

2009-01-01

125

Unified self-dual gauge theory of gravitational and electromagnetic fields

International Nuclear Information System (INIS)

A gauge theory with SO (1,4) x U (1) as structural group and having a spherically symmetric Minkowski space-time as base manifold is constructed. SO(1,4) denotes the de-Sitter (DS) group and U(1) is the abelian group of phase transformations. The direct-product structure of the structural group imposes the introduction of the tetrads and spin connection as gauge fields (or potentials) of the gravitational field and of the potential vector describing the electromagnetic field in our unified gauge theory. The strength tensors of these gauge potentials are calculated considering a model with spherically symmetric fields. Then, the self-duality equations are obtained and their solutions are analyzed. It is shown that these equations admit the DS solution. In contrast, it is established that the Reissner-Nordstroem (RN) solution is not a self-dual one. However, the Yang-Mills field equations have both DS and RN as their solutions. (author)

126

All anomalous velocity increases until now observed during the Earth flybys of the spacecrafts Galileo, NEAR, Rosetta, Cassini and Messenger have been correctly calculated by computer simulation using an asymmetric potential term in addition to the Newtonian potential. The specific characteristic of this term is the lack of coupling to the rotation of the Earth or to the direction of other gravitational sources such as the Sun or Moon. Instead, the asymmetry is oriented in the direction of the Earth's motion within an assumed unique reference frame. With this assumption, the simulation results of the Earth flybys Galileo1, NEAR, Rosetta1 and Cassini hit the observed nominal values, while for the flybys Galileo2 and Messenger, which for different reasons are measured with uncertain anomaly values, the simulated anomalies are within plausible ranges. Furthermore, the shape of the simulated anomaly curve is in qualitative agreement with the measured Doppler residuals immediately following the perigee of the firs...

Busack, Hans-Juergen

2007-01-01

127

Hawking radiation from the dilaton—(anti) de Sitter black hole via covariant anomaly

International Nuclear Information System (INIS)

Adopting the anomaly cancellation method, initiated by Robinson and Wilczek recently, this paper discusses Hawking radiation from the dilaton—(anti) de Sitter black hole. To save the underlying gauge and general covariance, it introduces covariant fluxes of gauge and energy-momentum tensor to cancel the gauge and gravitational anomalies. The result shows that the introduced compensating fluxes are equivalent to those of a 2-dimensional blackbody radiation at Hawking temperature with appropriate chemical potential. (general)

128

The Dilaton Wess-Zumino Action in 6 Dimension from Weyl Gauging: Local Anomalies and Trace Relations

We extend a previous analysis on the derivation of the dilaton Wess-Zumino (WZ) action in $d=4$, based on the method of Weyl gauging, to $6$ dimensions. As in the previous case, we discuss the structure of the same action in dimensional regularization using 6-dimensional Weyl invariants, extracting the dilaton interactions in the most general scheme, with the inclusion of the local anomaly terms. As an application, we present the WZ action for the (2,0) tensor multiplet, which has been investigated in the past in the context of the $AdS_7/CFT_6$ holographic anomaly matching. We then extend to $d=6$ the investigation of fully traced correlation functions of EMT's, formerly presented in $d=4$, showing that their hierarchy is functionally related only to the first 6 correlators. We give the explicit expressions of these in the most general scheme, up to rank-4.

Coriano, Claudio; Marzo, Carlo; Serino, Mirko

2013-01-01

129

International Nuclear Information System (INIS)

We extend a previous analysis on the derivation of the dilaton Wess–Zumino (WZ) action in d = 4, based on the method of Weyl gauging, to six dimensions. As in the previous case, we discuss the structure of the same action in dimensional regularization using six-dimensional Weyl invariants, extracting the dilaton interactions in the most general scheme, with the inclusion of the local anomaly terms. As an application, we present the WZ action for the (2,0) tensor multiplet, which has been investigated in the past in the context of the AdS7/CFT6 holographic anomaly matching. We then extend to d = 6 the investigation of fully traced correlation functions of energy–momentum tensor’s, formerly presented in d = 4, showing that their hierarchy is functionally related only to the first six correlators. We give the explicit expressions of these in the most general scheme, up to rank-4. (paper)

130

Covariant Lorentz anomalies in higher dimensional space

International Nuclear Information System (INIS)

The covariant Lorentz anomalies are evaluated by both the path integral and the topological methods, when Weyl fermions couple with the gauge and gravitational fields. In 2,4,6-dimensional curved space, the difference between the results obtained by the two methods is removed by counterterms and the equivalence of both methods is proved. It is shown that the Lorentz anomalies in flat space of arbitrary dimensions are eliminated. (author)

131

International Nuclear Information System (INIS)

The standard model SU(2)LxU(1)Y gauging of the Wess-Zumino-Witten term requires a modified counterterm when background fields, needed to generate the full set of currents, are introduced. The modified counterterm plays an essential role in properly defining covariant global currents and their anomalies. For example, it is required in order to correctly derive the gauge-invariant baryon number current and its anomalous divergence. The background fields can also be promoted to a description of the physical spin-1 vector and axial-vector mesons in QCD and the counterterm leads to novel interactions. These are (pseudo)Chern-Simons terms, such as ???????Z???A? and ???????±W?±??A? that mediate new interactions between neutrinos and photons at finite baryon density.

132

Heineman Prize Lecture: Anomaly Cancellation: A Retrospective

The mechanism by which gauge and gravitational anomalies cancel in certain string theories is reviewed. A few new tricks are introduced to make the derivation a little simpler, and the string-theoretic interpretation a little clearer, than in the original 1984 work.

Schwarz, John

2002-04-01

133

International Nuclear Information System (INIS)

The Morris-Thorne wormhole and vacuum equations in the conformal Poincare-gauge theory of gravitation are considered. It is shown that wormholes cannot be realized as configurations of a '' usual '' matter. It is obtained also that dynamic vacuum solutions for spherical symmetric case coincide with the corresponding GR solutions. (authors)

134

Frequency-domain algorithm for the Lorenz-gauge gravitational self-force

State-of-the-art computations of the gravitational self-force (GSF) on massive particles in black hole spacetimes involve numerical evolution of the metric perturbation equations in the time-domain, which is computationally very costly. We present here a new strategy, based on a frequency-domain treatment of the perturbation equations, which offers considerable computational saving. The essential ingredients of our method are (i) a Fourier-harmonic decomposition of the Lorenz-gauge metric perturbation equations and a numerical solution of the resulting coupled set of ordinary equations with suitable boundary conditions; (ii) a generalized version of the method of extended homogeneous solutions [Phys. Rev. D {\\bf 78}, 084021 (2008)] used to circumvent the Gibbs phenomenon that would otherwise hamper the convergence of the Fourier mode-sum at the particle's location; and (iii) standard mode-sum regularization, which finally yields the physical GSF as a sum over regularized modal contributions. We present a work...

Akcay, Sarp; Barack, Leor

2013-01-01

135

We study a finite basic structure that possibly underlies the observed elementary quantum fields with gauge and gravitational interactions. Realistic wave functions of locally interacting quantum fields emerge naturally as fitting functions for the generic distribution of many quantifiable properties of arbitrary static objects. We prove that in any quantum theory with the superposition principle, evolution of a current state of fields unavoidably continues along alternate routes with every conceivable Hamiltonian for the fields. This applies to the emergent quantum fields too. Yet the Hamiltonian is unambiguous for isolated emergent systems with sufficient local symmetry. The other emergent systems, without specific physical laws, cannot be inhabitable. The acceptable systems are eternally inflating universes with reheated regions. We see how eternal inflation perpetually creates new short-scale physical degrees of freedom and why they are initially in the ground state. In the emergent quantum worlds probabi...

Bashinsky, Sergei

2015-01-01

136

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

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

Scheck, Florian

2012-01-01

137

Chiral gauge theories revisited

Contents: 1. Introduction, 2. Chiral gauge theories & the gauge anomaly, 3. The regularization problem, 4. Weyl fermions from 4+1 dimensions, 5. The Ginsparg-Wilson relation, 6. Gauge-invariant lattice regularization of anomaly-free theories.

Lu?scher, Martin

2001-01-01

138

Holomorphy, rescaling anomalies and exact beta functions in supersymmetric gauge theories

International Nuclear Information System (INIS)

There have been known exact'' beta functions for the gauge coupling in N=1 supersymmetric gauge theories, the so-called NSVZ beta functions. Shifman and Vainshtein (SV) further related these beta functions to the exact 1-loop running of the Wilsonian'' gauge coupling. All these results, however, remain somewhat mysterious. We attempt to clarify these issues by presenting new perspectives on the NSVZ beta function. Our interpretation of the results is somewhat different than the one given by SV, having nothing to do with the distinction between Wilsonian'' and 1PI'' effective actions. Throughout we work in the context of the Wilsonian Renormalization Group; namely, as the cutoff of the theory is changed from M to M', we determine the appropriate changes in the bare couplings needed to keep the low energy physics fixed. The entire analysis is therefore free of infrared subtleties. When the bare Lagrangian given at the cutoff is manifestly holomorphic in the gauge coupling, we show that the required change in the holomorphic gauge coupling is exhausted at 1-loop to all orders of perturbation theory, and even non-perturbatively in some cases. On the other hand, when the bare Lagrangian has canonically normalized kinetic terms, we find that the required change in the gauge coupling is given by the NSVZ beta function. The higher order contributions in the NSVZ beta function are due to anomalous Jacobians under the rescaling of thealous Jacobians under the rescaling of the fields done in passing from holomorphic to canonical normalization. We also give prescriptions for regularizing certain N=1 theories with an ultraviolet cutoff M preserving manifest holomorphy, starting from finite N=4 and N=2 theories. It is then in principle possible to check the validity of the exact beta function by higher order calculations in these theories. (author)

139

Two potential coefficient fields that are complete to degree and order 360 have been computed. One field (OSU86E) excludes geophysically predicted anomalies while the other (OSU86F) includes such anomalies. These fields were computed using a set of 30' mean gravity anomalies derived from satellite altimetry in the ocean areas and from land measurements in North America, Europe, Australia, Japan and a few other areas. Where no 30' data existed, 1 deg x 1 deg mean anomaly estimates were used if available. No rigorous combination of satellite and terrestrial data was carried out. Instead advantage was taken of the adjusted anomalies and potential coefficients from a rigorous combination of the GEML2' potential coefficient set and 1 deg x 1 deg mean gravity anomalies. The two new fields were computed using a quadrature procedure with de-smoothing factors. The spectra of the new fields agree well with the spectra of the fields with 1 deg x 1 deg data out to degree 180. Above degree 180 the new fields have more power. The fields have been tested through comparison of Doppler station geoid undulations with undulations from various geopotential models. The agreement between the two types of undulations is approximately + or - 1.6 m. The use of a 360 field over a 180 field does not significantly improve the comparison. Instead it allows the comparison to be done at some stations where high frequency effects are important. In addition maps made in areas of high frequency information (such as trench areas) clearly reveal the signal in the new fields from degree 181 to 360.

Rapp, Richard H.; Cruz, Jaime Y.

1986-01-01

140

AdS solutions in gauge supergravities and the global anomaly for the product of complex two-cycles

Energy Technology Data Exchange (ETDEWEB)

Cohomological methods are applied for the special set of solutions corresponding to rotating branes in arbitrary dimensions, AdS black holes (which can be embedded in ten or eleven dimensions), and gauge supergravities. A new class of solutions is proposed, the Hilbert modular varieties, which consist of the 2n-fold product of the two-spaces H{sup n} /{gamma} (where H{sup n} denotes the product of n upper half-planes, H {sup 2}, equipped with the co-compact action of {gamma} is contained in SL(2, R){sup n}) and (H {sup n}){sup *}/{gamma} (where (H {sup 2}){sup *}=H {sup 2}{gamma} and {gamma} is a congruence subgroup of SL(2, R) {sup n}). The cohomology groups of the Hilbert variety, which inherit a Hodge structure (in the sense of Deligne), are analyzed, as well as bifiltered sequences, weight and Hodge filtrations, and it is argued that the torsion part of the cuspidal cohomology is involved in the global anomaly condition. Indeed, in the presence of the cuspidal part, all cohomology classes can be mapped to the boundary of the space and the cuspidal contribution can be involved in the global anomaly condition. (orig.)

Bytsenko, A.A. [Universidade Estadual de Londrina, Departamento de Fisica, Caixa Postal 6001, Londrina-Parana (Brazil); Elizalde, E. [Universitat Autonoma de Barcelona, Consejo Superior de Investigaciones Cientificas (ICE/CSIC) and Institut d' Estudis Espacials de Catalunya (IEEC), Facultat de Ciencies, Bellaterra (Barcelona) (Spain)

2011-03-15

141

Induced Spin from the $ISO(2,1)$ Gauge Theory with the Gravitational Chern-Simons Term

In the context of $ISO(2,1)$ gauge theory, we consider $(2+1)$-dimensional gravity with the gravitational Chern-Simons term (CST). This formulation allows the `exact' solution for the system coupled to a massive point particle (which is not the case in the conventional Chern-Simons gravity). The solution exhibits locally trivial structure even with the CST, although still shows globally nontrivialness such as the conical space and the helical time structure. Since the soluti...

Cho, Jin-ho; Lee, Hyuk-jae

1995-01-01

142

We present an algorithm for calculating the metric perturbations and gravitational self-force for extreme-mass-ratio inspirals (EMRIs) with eccentric orbits. The massive black hole is taken to be Schwarzschild and metric perturbations are computed in Lorenz gauge. The perturbation equations are solved as coupled systems of ordinary differential equations in the frequency domain. Accurate local behavior of the metric is attained through use of the method of extended homogeneous solutions and mode-sum regularization is used to find the self-force. We focus on calculating the self-force with sufficient accuracy to ensure its error contributions to the phase in a long term orbital evolution will be $\\delta\\Phi \\lesssim 10^{-2}$ radians. This requires the orbit-averaged force to have fractional errors $\\lesssim 10^{-8}$ and the oscillatory part of the self-force to have errors $\\lesssim 10^{-3}$ (a level frequently easily exceeded). Our code meets this error requirement in the oscillatory part, extending the reach...

Osburn, Thomas; Evans, Charles; Hopper, Seth

2014-01-01

143

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

International Nuclear Information System (INIS)

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

144

International Nuclear Information System (INIS)

A prescription is given for point-splitting in a curved space-time background which is a natural generalization of that familiar in quantum electrodynamics and Yang-Mills theory. It is applied (to establish its validity) to the verification of the gravitational anomaly in the divergence of a fermion axial current. Notable features of the prescription are that it defines a point-split current which can be differentiated straightforwardly, and that it involves a natural way of averaging (four dimensionally) over the directions of point splitting. The method can extend directly from the spin-1/2 fermion case treated to other cases, e.g. to spin -3/2 Rarita-Schwinger fermions. (author)

145

Exact results in two-dimensional chiral hydrodynamics with gravitational anomalies

Energy Technology Data Exchange (ETDEWEB)

An exact formulation of two-dimensional chiral hydrodynamics with diffeomorphism and conformal anomalies is provided. The constitutive relation involving the stress tensor is computed. It reveals a one parameter class of solutions which is a new result. For a particular value of this parameter, the results found in the gradient expansion scheme are reproduced. Moreover, the constitutive relation is analogous to the corresponding relation for an ideal fluid, appropriately modified to include the chirality property, which has also been derived here. (orig.)

Banerjee, Rabin [S. N. Bose National Centre for Basic Sciences, Kolkata (India)

2014-04-15

146

Gauge structure, anomalies and mass generation in a three dimensional thirring model

International Nuclear Information System (INIS)

We consider a three dimensional model of spinor fields with a Thirring like, quadrilinear self interaction. Using either two or four component Dirac spinors, we prove that the 1/N expansion for the model is renormalizable if a gauge structure to select physical quantities is introduced. For certain values of the coupling the leading 1/N approximation exihibits bound state poles. Dynamical breaking of parity or chiral symmetry is shown to occur as a cooperative effect of different orders of 1/N, if N is smaller than the critical value Nc = 128/x2D', where D is two or four depending on wether the fermion field has two or four components. (author)

147

We address the question of whether the LambdaCDM model produces enough substructure in galaxy scale dark matter halos to cause the observed image flux anomalies in lensed QSOs observed in the radio and mid-infrared. We create a very large number of simulated lenses with finite source sizes to compare with the data. After analysing these simulations, our conclusions are: 1) The finite size of the source is important. The point source approximation commonly used can cause large and biased results. 2) When we randomly select lens models that are distorted from a Singular Isothermal Ellipsoid in reasonable ways, but do not contain substructure, the flux anomalies are not reproduced. 3) We find new upper bounds on the amount of substructure from the constraint that no simple single-galaxy lenses have been observed with a single source having more than four well separated images. 4) The lower bound on the amount of substructure is set by the frequency of image flux anomalies and is largely a bound on the surface ma...

Metcalf, R Benton

2010-01-01

148

Gauge theories, time-dependence of the gravitational constant and antigravity in the early universe

International Nuclear Information System (INIS)

It is shown that the interaction of the gravitational field with matter leads to a strong modification of the effective gravitational constant in the early universe. In certain cases this leads even to the change of sign of the gravitational constant, i.e. to antigravity in the early universe. (orig.)

149

We present an algorithm for calculating the metric perturbations and gravitational self-force for extreme-mass-ratio inspirals (EMRIs) with eccentric orbits. The massive black hole is taken to be Schwarzschild, and metric perturbations are computed in Lorenz gauge. The perturbation equations are solved as coupled systems of ordinary differential equations in the frequency domain. Accurate local behavior of the metric is attained through use of the method of extended homogeneous solutions, and mode-sum regularization is used to find the self-force. We focus on calculating the self-force with sufficient accuracy to ensure its error contributions to the phase in a long-term orbital evolution will be ? ? ?1 0-2 rad . This requires the orbit-averaged force to have fractional errors ?1 0-8 and the oscillatory part of the self-force to have errors ?1 0-3 (a level frequently easily exceeded). Our code meets this error requirement in the oscillatory part, extending the reach to EMRIs with eccentricities of e ?0.8 , if augmented by use of fluxes for the orbit-averaged force, or to eccentricities of e ?0.5 when used as a stand-alone code. Further, we demonstrate accurate calculations up to orbital separations of a ?100 M , beyond that required for EMRI models and useful for comparison with post-Newtonian theory. Our principal developments include (1) use of fully constrained field equations, (2) discovery of analytic solutions for even-parity static modes, (3) finding a preconditioning technique for outer homogeneous solutions, (4) adaptive use of quad precision, (5) jump conditions to handle near-static modes, and (6) a hybrid scheme for high eccentricities.

Osburn, Thomas; Forseth, Erik; Evans, Charles R.; Hopper, Seth

2014-11-01

150

Stress-tensor trace anomaly in a gravitational metric: General theory, Maxwell field

International Nuclear Information System (INIS)

The renormalization of the vacuum expectation value of the stress-energy tensor of a scalar field propagating in a curved space-time with an arbitrary metric was discussed in a previous paper. A new regularization scheme was introduced which employs a continuation in the dimensionality of space-time implemented with a proper-time representation of the Green's function. Here we present a more general formulation of this method which clarifies its basic features and which explicitly displays the stress tensor as the metric functional derivative of the one-loop action functional. We apply this more general formulation to both the scalar field theory and to the electrodynamic, Maxwell theory. Although the trace of the stress tensor formally vanishes both for the massless scalar field and for the Maxwell field, the trace of the renormalized vacuum expectation value of the stress tensor does not vanish for either theory. These finite-trace anomalies cannot be removed by adding a finite local counterterm into the Lagrange function. The anomalies are intimately related to the infinite scalar counterterms that are needed to render the action finite

151

An anomaly-free model in six dimensions

International Nuclear Information System (INIS)

We show that a gauged supergravity theory based on E6xE7xU(1) is free of gauge and gravitational anomalies in six dimensions. It compactifies to (Minkowski)4xS2 by the standard monopole mechanism. With a monopole of strength n in E6, the resulting four-dimensional theory exhibits chiral SO(10)xU(1) with 2|n| families (and no antifamilies). Supersymmetry is broken. (author)

152

International Nuclear Information System (INIS)

The lectures given cover the topological effects in gauge field theories, fermionic chiral anomalies, and some relationships between the two. Gauge field theories in three and four space-time dimensions are considered. Topological terms as external U(1) functional gauge potential connections in field space are discussed. Both the structure and physical impact of anomalies are described. 17 refs

153

International Nuclear Information System (INIS)

We show that the Implicit Regularization Technique is useful to display quantum symmetry breaking in a complete regularization independent fashion. Arbitrary parameters are expressed by finite differences between integrals of the same superficial degree of divergence whose value is fixed on physical grounds (symmetry requirements or phenomenology). We study Weyl fermions on a classical gravitational background in two dimensions and show that, assuming Lorentz symmetry, the Weyl and Einstein Ward identities reduce to a set of algebraic equations for the arbitrary parameters which allows us to study the Ward identities on equal footing. We conclude in a renormalization independent way that the axial part of the Einstein Ward identity is always violated. Moreover whereas we can preserve the pure tensor part of the Einstein Ward identity at the expense of violating the Weyl Ward identities we may as well violate the former and preserve the latter

154

We show that the Implicit Regularization Technique is useful to display quantum symmetry breaking in a complete regularization independent fashion. Arbitrary parameters are expressed by finite differences between integrals of the same superficial degree of divergence whose value is fixed on physical grounds (symmetry requirements or phenomenology). We study Weyl fermions on a classical gravitational background in two dimensions and show that, assuming Lorentz symmetry, the Weyl and Einstein Ward identities reduce to a set of algebraic equations for the arbitrary parameters which allows us to study the Ward identities on equal footing. We conclude in a renormalization independent way that the axial part of the Einstein Ward identity is always violated. Moreover whereas we can preserve the pure tensor part of the Einstein Ward identity at the expense of violating the Weyl Ward identities we may as well violate the former and preserve the latter.

Souza, L A M; Nemes, M C; Souza, Leonardo A. M.; Sampaio, Marcos

2006-01-01

155

The global anomalies of (2,0) superconformal field theories in six dimensions

We compute the global gauge and gravitational anomalies of the A-type (2,0) superconformal quantum field theories in six dimensions, and conjecture a formula valid for the D- and E-type theories. We show that the anomaly contains terms that do not contribute to the local anomaly but that are crucial for the consistency of the global anomaly. A side result is an intuitive picture for the appearance of Hopf-Wess-Zumino terms on the Coulomb branch of the (2,0) theories.

Monnier, Samuel

2014-01-01

156

Boost invariance of the gravitational field dynamics: quantization without time gauge

We perform a canonical quantization of gravity in a second-order formulation, taking as configuration variables those describing a 4-bein, not adapted to the space-time splitting. We outline how, neither if we fix the Lorentz frame before quantizing, nor if we perform no gauge fixing at all, is invariance under boost transformations affected by the quantization.

Cianfrani, Francesco; Montani, Giovanni

2007-01-01

157

International Nuclear Information System (INIS)

Stringent presentation of field theory, mediates the connection from the classicalelectrodynamics up to modern gauge theories. The compact presentation is ideal for the bachelor study. New chapter on general relativity theory. Deepens the learned by numerous application from laser physic, metamaterials and different more. Theoretical physics 3. Classical field theory. On electrodynamics, non-Abelian, and gravitation is the third of five volumes on theoretical physics by professor Scheck. The cycle theoretical physics comprehends: Volume 1: Mechanics. From Newtons law to the deterministic chaos. Volume 2: Nonrelativistic quantum theory. From the hydrogen atom to the many-particle systems. Volume 3: Classical field theory. From the electrodynamics to the gauge theories. Volume 5: From the laws of thermodynamics to the quantum statistics. This textbook mediates modern theoretical physics in string presentation illustrated by many examples. It contains numerous problems with solution hints ore exemplary, complete solutions. The third edition was revised in many single topics, especially the chapter on general relativity theory was supplemented by an extensive analysis of the Schwarzschild solution.

158

D-brane Charges in Gravitational Duals of 2+1 Dimensional Gauge Theories and Duality Cascades

We perform a systematic analysis of the D-brane charges associated with string theory realizations of d=3 gauge theories, focusing on the examples of the N=4 supersymmetric U(N)xU(N+M) Yang-Mills theory and the N=3 supersymmetric U(N)xU(N+M) Yang-Mills-Chern-Simons theory. We use both the brane construction of these theories and their dual string theory backgrounds in the supergravity approximation. In the N=4 case we generalize the previously known gravitational duals to arbitrary values of the gauge couplings, and present a precise mapping between the gravity and field theory parameters. In the N=3 case, which (for some values of N and M) flows to an N=6 supersymmetric Chern-Simons-matter theory in the IR, we argue that the careful analysis of the charges leads to a shift in the value of the B-field in the IR solution by 1/2, in units where its periodicity is one, compared to previous claims. We also suggest that the N=3 theories may exhibit, for some values of N and M, duality cascades similar to those of ...

Aharony, Ofer; Hirano, Shinji; Ouyang, Peter

2009-01-01

159

Supersymmetry anomalies: Further results

International Nuclear Information System (INIS)

We consider anomalies in local supersymmetry. An expression for the gauge (Lorentz) noninvariant part of this anomaly for 2n dimensional spacetime is given. The result agrees with explicit calculations in two dimensions. Complete expressions for rigid supersymmetry anomalies in two, four and six dimensions are also given. (orig.)

160

Stringent experimental constraints have raised the lower limit on the masses of squarks to TeV levels, while compatibility with the mass of the Higgs boson provides an upper limit. This two-sided bound has lead to the emergence of Mini-Split theories where gauginos are not far removed from the electroweak scale while scalars are somewhat heavier. This small hierarchy modifies the spectrum of standard anomaly and gauge mediation, leading to Mini-Split deflected anomaly and gauge mediation models. In this paper, we study LHC constraints on these models and their prospects at a 100 TeV collider. Current constraints on their parameter space come from ATLAS and CMS supersymmetry searches, the known mass of the Higgs boson, and the absence of a color-breaking vacuum. Prospects at a 100 TeV collider are obtained from these same theoretical constraints in conjunction with background estimates. As would be expected from renormalization group effects, a slightly lighter third generation of squarks is assumed. Higgsinos...

Beauchesne, Hugues; Gregoire, Thomas

2015-01-01

161

Recently, with the ``bounching photon'' treatment, the gauge invariance of the response of an interferometer to scalar gravitational waves (SGWs) has been demonstred in its full frequency dependence in three different gauges well known in literature, while in previous works it was been shown only in the low frequencies approximation. In this paper the analysis of the response function for SGWs is generalized in its full angular dependence and directly in the gauge of the local observer, which is the gauge of a laboratory enviroment on Earth. The result is used for anlyzing the cross - correlation between the two LIGO interferometers in their advanced configuration for a potential detection of a stochastic bacground of SGWs. An inferior limit for the integration time of a potential detection is released.

Corda, C

2006-01-01

162

Chiral Gravity Waves and Leptogenesis in Inflationary Models with non-Abelian Gauge Fields

We present a leptogenesis scenario associated with inflationary models involving non-Abelian gauge fields within the standard model of particle physics (SM). We show that this class of inflationary models generates intrinsic birefringent gravitational waves that through the gravitational chiral anomaly in SM, can naturally create a net lepton number density. The CP violating interaction is produced by tensor fluctuations of the gauge field, while the efficiency of this process is determined by the effective background value of the gauge field. We demonstrate that this mechanism can create the observed value of baryon to photon number density in a natural range of parameters of these models.

Maleknejad, Azadeh

2014-01-01

163

Path integral quantization of gravitational interactions

International Nuclear Information System (INIS)

Some of the local symmetry properties of quantum field theory in curved space-time and quantized gravitational interactions are discussed. We concentrate on local symmetry properties, and thus the asymptotically flat space-time is assumed, whenever necessary, in the hope that the precise boundary conditions will not modify the short distance structure in quantum theory. We adopt the DeWitt-Faddeev-Popov prescription of the Feynman path integral with a complete gauge fixing. The topics discussed include: (i) A brief review of the path integral derivation of chiral anomalies in flat space-time. (ii) The specification of the gravitational path integral measure, which avoids all the ''fake'' gravitational anomalies, and the applications of this path integral prescription to 1) effective potential in generalized Kaluza-Klein theory, 2) 4-dimensional conformal anomalies, 3) conformal symmetry in pure conformal gravity, 4) bosonic string theory as a gravitational theory in d = 2, 5) Virasoro condition and the Wheeler-DeWitt equation in the path integral formalism, 6) gravitational anomalies and the definition of the energy-momentum tensor. (author)

164

Exact vacuum solutions of 4-dimensional metric-affine gauge theories of gravitation

Energy Technology Data Exchange (ETDEWEB)

We present two exact spherically symmetric vacuum solutions of gauge theories of gravity on a space-time with non metric-compatible connection. One of them is defined on a Weyl-Cartan spacetime and the other on a general metric-affine space. We consider Lagrangians which include terms quadratic in the irreducible parts of the curvature, the torsion, and the nonmetricity. The metric part of both solutions is of the Reissner-Nordstroem type and includes a contribution of an effective dilatation charge. A nontrivial Weyl 1-form is also common to both solutions. It resembles a Coulomb potential originating from the dilatation charge. The torsion is closely related to the nonmetricity. (orig.)

Tresguerres, R. (Koeln Univ. (Germany). Inst. fuer Theoretische Physik)

1995-01-01

165

Search at the Mainz Microtron for light massive gauge bosons relevant for the muon g-2 anomaly.

A massive, but light, Abelian U(1) gauge boson is a well-motivated possible signature of physics beyond the standard model of particle physics. In this Letter, the search for the signal of such a U(1) gauge boson in electron-positron pair production at the spectrometer setup of the A1 Collaboration at the Mainz Microtron is described. Exclusion limits in the mass range of 40??MeV/c^{2} to 300??MeV/c^{2}, with a sensitivity in the squared mixing parameter of as little as ?^{2}=8×10^{-7} are presented. A large fraction of the parameter space has been excluded where the discrepancy of the measured anomalous magnetic moment of the muon with theory might be explained by an additional U(1) gauge boson. PMID:24949757

Merkel, H; Achenbach, P; Ayerbe Gayoso, C; Beranek, T; Beri?i?, J; Bernauer, J C; Böhm, R; Bosnar, D; Correa, L; Debenjak, L; Denig, A; Distler, M O; Esser, A; Fonvieille, H; Friš?i?, I; Gómez Rodríguez de la Paz, M; Hoek, M; Kegel, S; Kohl, Y; Middleton, D G; Mihovilovi?, M; Müller, U; Nungesser, L; Pochodzalla, J; Rohrbeck, M; Ron, G; Sánchez Majos, S; Schlimme, B S; Schoth, M; Schulz, F; Sfienti, C; Sirca, S; Thiel, M; Tyukin, A; Weber, A; Weinriefer, M

2014-06-01

166

International Nuclear Information System (INIS)

Investigations of several problems of gravitation are discussed. The question of the existence of black holes is considered. While black holes like those in Einstein's theory may not exist in other gravity theories, trapped surfaces implying such black holes certainly do. The theories include those of Brans-Dicke, Lightman-Lee, Rosen, and Yang. A similar two-tensor theory of Yilmaz is investigated and found inconsistent and nonviable. The Newman-Penrose formalism for Riemannian geometries is adapted to general gravity theories and used to implement a search for twisting solutions of the gravity theories for empty and nonempty spaces. The method can be used to find the gravitational fields for all viable gravity theories. The rotating solutions are of particular importance for strong field interpretation of the Stanford/Marshall gyroscope experiment. Inhomogeneous cosmologies are examined in Einstein's theory as generalizations of homogeneous ones by raising the dimension of the invariance groups by one more parameter. The nine Bianchi classifications are extended to Rosen's theory of gravity for homogeneous cosmological models

167

The global anomaly of the self-dual field in general backgrounds

We prove a formula for the global gravitational anomaly of the self-dual field theory in the presence of background gauge fields, assuming the results of arXiv:1110.4639. Along the way, we also clarify various points about the self-dual field theory. In particular, we give a general definition of the theta characteristic entering its partition function and settle the issue of its possible metric dependence. We treat the cohomological version of type IIB supergravity as an example of the formalism. We show the apparent existence of a mixed gauge-gravitational global anomaly, occurring when the B-field and Ramond-Ramond 2-form gauge fields have non-trivial Wilson lines, and suggest a way in which it could cancel.

Monnier, Samuel

2013-01-01

168

On the simple evaluation of chiral anomalies in the path integral approach

International Nuclear Information System (INIS)

We comment on the relation between the Schwinger's proper time method and the one-dimensional supersymmetric path integral method in the evaluation of chiral anomalies in gauge and gravitational interactions. For this purpose, we introduce a modified one-dimensional path integral which is directly related to the proper time method by a Legendre transformation. This modified scheme provides a simple way of evaluating chiral anomalies. The one-dimensional path integral method is also shown to work for the trace anomaly in 4-dimensional flat space-time. (author)

169

Simple evaluation of chiral anomalies in the path-integral approach

International Nuclear Information System (INIS)

We comment on the relation between Schwinger's proper-time method and the one-dimensional supersymmetric path-integral method in the evaluation of chiral anomalies in gauge and gravitational interactions. For this purpose, we introduce a modified one-dimensional path integral which is directly related to the proper-time method by a Legendre transformation. This modified scheme provides a simple way of evaluating chiral anomalies. The one-dimensional path-integral method is also shown to work for the trace anomaly in four-dimensional flat space-time

170

Anomaly analysis of Hawking radiation from Kaluza-Klein black hole with squashed horizon

International Nuclear Information System (INIS)

Considering gravitational and gauge anomalies at the horizon, a new method to derive Hawking radiation from black holes has been developed by Wilczek et al. In this paper, we apply this method to non-rotating and rotating Kaluza-Klein black holes with squashed horizon, respectively. For the rotating case, we found that, after dimensional reduction, an effective U(1) gauge field is generated by an angular isometry. The results show that the gauge current and energy-momentum tensor fluxes are exactly equivalent to Hawking radiation from the event horizon. (orig.)

171

Anomalies in quantum field theory and differential geometry

International Nuclear Information System (INIS)

Anomalies in field theory appeared first in perturbative computations involving Feynman diagrams. It is only recently that differential geometric techniques have been used to obtain the form of gauge and gravitational anomalies in a direct and simple way. This is possible because of the topological nature of the anomaly. In the first chapter of this thesis the gauged Wess-Zumino action is constructed by differential geometry methods. After reviewing the relevant techniques, an expression for the action valid in any (even) number of space-time dimensions is obtained. This expression is compared with Witten's result in four dimensions. The link between topology and the anomaly is provided by the appropriate index theorem. The index density is a supersymmetric invariant polynomial from which the anomaly and other related objects can be obtained through the use of the ''descent equations.'' A new proof of the Atiyah-Singer index theorem for the Dirac operator is presented. This proof is based on the use of a WKB approximation to evaluate the supertrace of the kernel for a supersymmetric hamiltonian. The necessary WKB techniques are developed and mechanical systems with bosonic and fermionic degrees of freedom are discussed

172

Anomalies in quantum field theory and differential geometry

Energy Technology Data Exchange (ETDEWEB)

Anomalies in field theory appeared first in perturbative computations involving Feynman diagrams. It is only recently that differential geometric techniques have been used to obtain the form of gauge and gravitational anomalies in a direct and simple way. This is possible because of the topological nature of the anomaly. In the first chapter of this thesis the gauged Wess-Zumino action is constructed by differential geometry methods. After reviewing the relevant techniques, an expression for the action valid in any (even) number of space-time dimensions is obtained. This expression is compared with Witten's result in four dimensions. The link between topology and the anomaly is provided by the appropriate index theorem. The index density is a supersymmetric invariant polynomial from which the anomaly and other related objects can be obtained through the use of the ''descent equations.'' A new proof of the Atiyah-Singer index theorem for the Dirac operator is presented. This proof is based on the use of a WKB approximation to evaluate the supertrace of the kernel for a supersymmetric hamiltonian. The necessary WKB techniques are developed and mechanical systems with bosonic and fermionic degrees of freedom are discussed.

Manes, J.L.

1986-04-01

173

In the construction of a fundamental conformally-invariant gravitational theory for very early times in the universe or for very short distance scales, we need to invoke a symmetry-breaking mechanism so this theory can be transmuted into the conformally-noninvariant conventional Einstein theory that we see in the universe today at macroscopic distance scales. I here propose a simple and consistent way to achieve this breaking of conformal symmetry by the Higgs mechanism applied to a massless complex scalar field coupled to a massless vector field. Upon symmetry breaking, these scalar and vector fields acquire masses of the order of the Planck mass. Before symmetry breaking, the massless vector field obeys equations similar to those of the electromagnetic field, but it is distinct from it. This new vector field can be regarded as the Weyl gauge-vector for the transport of lengths in the conformal geometry.

Ohanian, Hans C

2015-01-01

174

Geometrical formulation of gauge theories

International Nuclear Information System (INIS)

We review some basic aspects of the geometry of gauge theories. Particularly, we introduce the concepts gauge potential, field intensity, matter field, gauge groups and symmetry of a physical configuration and we discuss the spontaneous symmetry breaking and the gauge theories of gravitation. 26 refs

175

Holographic renormalization of cascading gauge theories

We perform a holographic renormalization of cascading gauge theories. Specifically, we find the counter-terms that need to be added to the gravitational action of the backgrounds dual to the cascading theory of Klebanov and Tseytlin, compactified on an arbitrary four-manifold, in order to obtain finite correlation functions (with a limited set of sources). We show that it is possible to truncate the action for deformations of this background to a five dimensional system coupling together the metric and four scalar fields. Somewhat surprisingly, despite the fact that these theories involve an infinite number of high-energy degrees of freedom, we find finite answers for all one-point functions (including the conformal anomaly). We compute explicitly the renormalized stress tensor for the cascading gauge theories at high temperature and show how our finite answers are consistent with the infinite number of degrees of freedom. Finally, we discuss ambiguities appearing in the holographic renormalization we propose...

Aharony, O; Yarom, A; Aharony, Ofer; Buchel, Alex; Yarom, Amos

2005-01-01

176

Radiative corrections to axial anomaly

International Nuclear Information System (INIS)

It is shown that an anomaly in axial current divergence has more than one loop. The contribution, which has not been taken into account earlier, originates from photon-photon scattering diagrams. The radiative corrections for QED, nonAbelian gauge theory and supersymmetric gauge theory are calculated

177

Infinity and anomaly cancellation in superstring theories

International Nuclear Information System (INIS)

The status of calculations in string perturbation theory at the one-loop level is reviewed. The paper was presented to the workshop on 'Supersymmetry and its applications', Cambridge, United Kingdom, 1985. The subject is discussed under the topic headings: loops of open strings, closed-string loop amplitude, multi-loop amplitudes, one-loop chiral gauge anomalies, gauge invariance of tree diagrams, one-loop anomaly, and anomaly cancellations in the low-energy theory. (U.K.)

178

Anomaly poles as common signatures of chiral and conformal anomalies

International Nuclear Information System (INIS)

One feature of the chiral anomaly, analyzed in a perturbative framework, is the appearance of massless poles which account for it. They are identified by a spectral analysis of the anomaly graph and are usually interpreted as being of an infrared origin. Recent investigations show that their presence is not just confined in the infrared, but that they appear in the effective action under the most general kinematical conditions, even if they decouple in the infrared. Further studies reveal that they are responsible for the non-unitary behaviour of these theories in the ultraviolet (UV) region. We extend this analysis to the case of the conformal anomaly, showing that the effective action describing the interaction of gauge fields with gravity is characterized by anomaly poles that give the entire anomaly and are decoupled in the infrared (IR), in complete analogy with the chiral case. This complements a related analysis by Giannotti and Mottola on the trace anomaly in gravity, in which an anomaly pole has been identified in the corresponding correlator using dispersion theory in the IR. Our extension is based on an exact computation of the off-shell correlation function involving an energy-momentum tensor and two vector currents (the gauge-gauge-graviton vertex) which is responsible for the appearance of the anomaly.

179

Path Integrals and Anomalies in Curved Space

International Nuclear Information System (INIS)

Bastianelli and van Nieuwenhuizen's monograph 'Path Integrals and Anomalies in Curved Space' collects in one volume the results of the authors' 15-year research programme on anomalies that arise in Feynman diagrams of quantum field theories on curved manifolds. The programme was spurred by the path-integral techniques introduced in Alvarez-Gaume and Witten's renowned 1983 paper on gravitational anomalies which, together with the anomaly cancellation paper by Green and Schwarz, led to the string theory explosion of the 1980s. The authors have produced a tour de force, giving a comprehensive and pedagogical exposition of material that is central to current research. The first part of the book develops from scratch a formalism for defining and evaluating quantum mechanical path integrals in nonlinear sigma models, using time slicing regularization, mode regularization and dimensional regularization. The second part applies this formalism to quantum fields of spin 0, 1/2, 1 and 3/2 and to self-dual antisymmetric tensor fields. The book concludes with a discussion of gravitational anomalies in 10-dimensional supergravities, for both classical and exceptional gauge groups. The target audience is researchers and graduate students in curved spacetime quantum field theory and string theory, and the aims, style and pedagogical level have been chosen with this audience in mind. Path integrals are treated as calculational tools, and the notation and terminology are throughout taiotation and terminology are throughout tailored to calculational convenience, rather than to mathematical rigour. The style is closer to that of an exceedingly thorough and self-contained review article than to that of a textbook. As the authors mention, the first part of the book can be used as an introduction to path integrals in quantum mechanics, although in a classroom setting perhaps more likely as supplementary reading than a primary class text. Readers outside the core audience, including this reviewer, will gain from the book a heightened appreciation of the central role of regularization as a defining ingredient of a quantum field theory and will be impressed by the agreement of results arising from different regularization schemes. The readers may in particular enjoy the authors' 'brief history of anomalies' in quantum field theory, as well as a similar historical discussion of path integrals in quantum mechanics. (book review)

180

Holography with Gravitational Chern-Simons Term

The holographic description in the presence of gravitational Chern-Simons term is studied. The modified gravitational equations are integrated by using the Fefferman-Graham expansion and the holographic stress-energy tensor is identified. The stress-energy tensor has both conformal anomaly and gravitational or, if re-formulated in terms of the zweibein, Lorentz anomaly. We comment on the structure of anomalies in two dimensions and show that the two-dimensional stress-energy...

Solodukhin, Sergey N.

2005-01-01

181

International Nuclear Information System (INIS)

The six-dimensional gravitational and gauge anomaly-free E6xE7xU(1) theory requires change of the three-form field strength H by an additional Lorentz Chern-Simons three-form. The action with this modification by Randjbar-Daemi, Salam, Sezgin and Strathdee is supersymmetrized to linear order in the Noether expansion parameter ? without H. The equations of motion to this order are satisfied by monopole compactifications. (orig.)

182

We discuss the definitions of standard clocks in theories of gravitation. These definitions are motivated by the invariance of actions under different gauge symmetries. We contrast the definition of a standard Weyl clock with that of a clock in general relativity and argue that the historical criticisms of theories based on non-metric compatible connections by Einstein, Pauli and others must be considered in the context of Weyl's original gauge symmetry. We argue that standard Einsteinian clocks can be defined in non-Riemannian theories of gravitation by adopting the Weyl group as a local gauge symmetry that {\\it preserves the metric} and discuss the hypothesis that atomic clocks may be adopted to measure proper time in the presence of non-Riemannian gravitational fields. These ideas are illustrated in terms of a recently developed model of gravitation based on a non-Riemannian space-time geometry.

Teyssandier, P; Teyssandier, Pierre; Tucker, Robin W

1995-01-01

183

We discuss the definitions of standard clocks in theories of gravitation. These definitions are motivated by the invariance of actions under different gauge symmetries. We contrast the definition of a standard Weyl clock with that of a clock in general relativity and argue that the historical criticisms of theories based on non-metric compatible connections by Einstein, Pauli and others must be considered in the context of Weyl's original gauge symmetry. We argue that standard Einsteinian clocks can be defined in non-Riemannian theories of gravitation by adopting the Weyl group as a local gauge symmetry that preserves the metric and discuss the hypothesis that atomic clocks may be adopted to measure proper time in the presence of non-Riemannian gravitational fields. These ideas are illustrated in terms of a recently developed model of gravitation based on a non-Riemannian spacetime geometry.

Teyssandier, Pierre; Tucker, Robin W.

1996-01-01

184

On the renormalization of the theories with ?5-anomalies

International Nuclear Information System (INIS)

We show that the introduction of the non-local counterterm for the theories with ?5-anomalies restores the gauge invariance at quantum level. As an example we consider the strictly soluble two-dimensional model with ?5-anomalies. (author)

185

International Nuclear Information System (INIS)

We apply the Bogolyubov compensation principle to the gauge electro-weak interaction to demonstrate the spontaneous generation of an anomalous three-boson gauge invariant effective interaction. The non-trivial solution of the compensation equations uniquely defines the values of the parameters of the theory and the form factor of the anomalous interaction. The contribution of this interaction to the running EW coupling, ?ew(p2), gives its observable value ?ew(MW2)=0.0374, in satisfactory agreement to the experiment. The anomalous three-boson interaction gives a natural explanation of the well-known discrepancy in the muon g-2. The implications for EW studies at Tevatron and LHC are briefly discussed. (orig.)

186

Anomalies and de Sitter radiation from the generic black holes in de Sitter spaces

International Nuclear Information System (INIS)

Robinson-Wilczek's recent work shows that, the energy-momentum tensor flux required to cancel gravitational anomaly at the event horizon of a Schwarzschild-type black hole has an equivalent form to that of a (1+1)-dimensional blackbody radiation at the Hawking temperature. Motivated by their work, Hawking radiation from the cosmological horizons of the general Schwarzschild-de Sitter and Kerr-de Sitter black holes, has been studied by the method of anomaly cancellation. The result shows that the absorbing gauge current and energy momentum tensor fluxes required to cancel gauge and gravitational anomalies at the cosmological horizon are precisely equal to those of Hawking radiation from it. It should be emphasized that the effective field theory for generic black holes in de Sitter spaces should be formulated within the region between the event horizon (EH) and the cosmological horizon (CH), to integrate out the classically irrelevant ingoing modes at the EH and the classically irrelevant outgoing modes at the CH, respectively

187

The antifield formalism adapted in the exact renormalization group is found to be useful for describing a system with some symmetry, especially the gauge symmetry. In the formalism, the vanishing of the quantum master operator implies the presence of a symmetry. The QM operator satisfies a simple algebraic relation that will be shown to be related to the Wess-Zumino condition for anomalies. We also explain how an anomaly contributes to the QM operator.

Igarashi, Y.; Itoh, K.; Sato, M.; Sonoda, H.

2011-03-01

188

Gaugino-Assisted Anomaly Mediation

We present a model of supersymmetry breaking mediated through a small extra dimension. Standard model matter multiplets and a supersymmetry-breaking (or ``hidden'') sector are confined to opposite four-dimensional boundaries while gauge multiplets live in the bulk. The hidden sector does not contain a singlet and the dominant contribution to gaugino masses is via anomaly-mediated supersymmetry breaking. Scalar masses get contributions from both anomaly mediation and a tiny h...

Kaplan, David Elazzar; Kribs, Graham D.

2000-01-01

189

International Nuclear Information System (INIS)

We develop a systematic method to construct the gauged BRST symmetry for any theory. In this framework, it results as the combination of two basic symmetries of the gauge-fixed theory one considers: the BRST symmetry and the ghost number symmetry, this later being promoted to a local one. From this, we can derive a general relation between the BRST and the ghost number Noether currents. We then take advantage of the present method to elaborate a geometrical algorithm leading to the obtention of the gauged BRST symmetry for a large class of theories, in arbitrary dimensions of space. These involve systems of antisymmetric tensor gauge fields of arbitrary rank, eventually coupled to gravity. This algorithm allows us to derive algebraically the expressions for the possible consistent anomalies of the BRST Noether current algebras; various examples are explicitely discussed. The gauged BRST symmetry for the free bosonic string is also constructed and used to exhibit the link between the trace anomaly and the nilpotency anomaly of the BRST charge operator. In particular, when the Beltrami parametrization is introduced, we show that the corresponding BRST symmetry can be gauged in a way compatible with the holomorphic factorization. A further use of Ward-Slavnov identities constraining the BRST and ghost number current algebra allows us to recover the well-known local counterterm necessary, at the one-loop level, to render the BRST current a good conformal operator

190

How to test gravitation theories by means of gravitational-wave measurements

Gravitational-wave experiments are a potentially powerful tool for testing gravitation theories. Most theories in the literature predict rather different polarization properties for gravitational waves than are predicted by general relativity; and many theories predict anomalies in the propagation speeds of gravitational waves.

Thorne, K. S.

1974-01-01

191

... genetic terms used on this page Learning About Poland Anomaly What is Poland anomaly? What are the ... Anomaly Additional Resources for Poland Anomaly What is Poland anomaly? Named after Sir Alfred Poland, Poland anomaly ( ...

192

Consistency conditions for Kaluza-Klein anomalies

International Nuclear Information System (INIS)

General consistency requirements on anomalies in D = 2n dimensions are derived with topological techniques. It is shown that for a non-Abelian gauge theory the group-theoretic piece of the anomaly is an overall multiplicative factor for any even D> or =4

193

Stochastic perturbative derivation of the axial anomaly

International Nuclear Information System (INIS)

The axial anomaly is calculated as the infinite Langevin time limit of stochastic triangle diagrams. Their regularization is insured with the help of an analytic stochastic regulator. The usual axial anomaly is recovered only when the Langevin equations used to generate the perturbative expansion are gauge covariant. (orig.)

194

International Nuclear Information System (INIS)

In the proposed gauge a number of derivatives of the axial gravitational superfield H/sup m/ vanish at a given point in superspace. The remaining terms in the expansion of H/sup m/ in the neighborhood of this point correspond to the fundamental superfields R, R-bar, G, W, and W-bar, through which all the components of the torsion and curvature are expressed. The normal gauge significantly simplifies many considerations and calculations in supergravity

195

International Nuclear Information System (INIS)

In the gauge proposed a large number of derivatives of the axial gravitational superfield Hsup(m) vanish at a given point in superspace. The remaining derivatives of Hsup(m) are the values at z0 of the basic superfields R, anti R, G, W, anti W in terms of which torsion and curvature are expressible. The normal gauge simplifies significantly many considerations and calculations in supergravity

196

Radiative corrections to axial anomaly

International Nuclear Information System (INIS)

It is demonstrated that, contrary to the generally accepted viewpoint, the single-loop value is not the only one involved in the axial anomaly. Contributions which were not taken into account previously arise in diagrams for scattering of light by light (or gluons by gluons). The radiative corrections in quantum electrodynamics and in non-Abelian gauge theories are calculated. It is shown that in supersymmetric quantum electrodynamics the multi-loop contributions can explain the apparent contradiction between the axial anomaly and anomaly in the trace of the energy-momentum tensor. A complication arises in supersymmetric non-Abelian theories due to the dependence on the gauge in the matrix elements outside the mass surface

197

Supersymmetry: Kaluza-Klein theory, anomalies, and superstrings

International Nuclear Information System (INIS)

Progress in the search for a unified theory of elementary particles is reviewed. The supersymmetrical Kaluza-Klein theories are described: 11-, 10-, and 6-dimensional models of supergravity. The methods of spontaneous compactification, with whose help the four-dimensional theories are obtained, are described. The properties of the massless sector: zero modes in the Kaluza-Klein theories: and the question of the stability of vacuum solutions are discussed. An important criterion for the selection of a self-consistent theory is the absence of anomalies. The basic formulas for multidimensional chiral and gravitational anomalies are presented. The mechanism of the cancellation of the anomaly for Green and Schwarz's 10-dimensional effective field theory of superstrings with the gauge groups SO(32) and E8 x E8 is described. The basic concepts and the results of the theory of superstrings are presented. This theory has no divergences and is at the present time a very attractive candidate for a unified theory of elementary particles

198

Theory of gravitational interactions

This reference textbook is an up-to-date and self-contained introduction to the theory of gravitational interactions. The first part of the book follows the traditional presentation of general relativity as a geometric theory of the macroscopic gravitational field. A second, advanced part then discusses the deep analogies (and differences) between a geometric theory of gravity and the gauge theories of the other fundamental interactions. This fills a gap which is present in the context of the traditional approach to general relativity, and which usually makes students puzzled about the role of gravity. The necessary notions of differential geometry are reduced to the minimum, leaving more room for those aspects of gravitational physics of current phenomenological and theoretical interest, such as the properties of gravitational waves, the gravitational interactions of spinors, and the supersymmetric and higher-dimensional generalization of the Einstein equations. Theory of Gravitational Interactions will be o...

Gasperini, Maurizio

2013-01-01

199

Anomaly mediated supersymmetry breaking

International Nuclear Information System (INIS)

A discrepancy between the anomaly mediated supersymmetry breaking (AMSB) gaugino mass calculated from the work of Kaplunovsky and Louis (hep-th/9402005) (KL) and other calculations in the literature is explained, and it is argued that the KL expression is the correct one relevant to the Wilsonian action. Furthermore it is argued that the AMSB contribution to the squark and slepton masses should be replaced by the contribution pointed out by Dine and Seiberg (DS) which has nothing to do with Weyl anomalies. This is not in general equivalent to the AMSB expression, and it is shown that there are models in which the usual AMSB expression would vanish but the DS one is nonzero. In fact the latter has aspects of both AMSB and gauge mediated supersymmetry (SUSY) breaking. In particular like the latter, it gives positive squared masses for sleptons

200

Harmonic superspace formalism and the consistent chiral anomaly

International Nuclear Information System (INIS)

The harmonic superspace formalism has been used to construct the consistent chiral anomaly in N = 1, d = 6 supersymmetric Yang-Mills thoery. The expressions of the gauge anomaly ?/sub s//sup phi/ and of the supersymmetric anomaly ?/sub SUSY//sup phi/ are given together with the consistent condition. 7 refs

201

Erik Verlinde's proposal of the emergence of the gravitational force as an entropic force is extended to abelian and non-abelian gauge fields and to matter fields. This suggests a picture with no fundamental forces or forms of matter whatsoever.

Freund, Peter G. O.

2010-01-01

202

Energy Technology Data Exchange (ETDEWEB)

The 76. session of the summer school in theoretical physics was devoted to recent developments in string theory, gauge theories and quantum gravity. Superstring theory is the leading candidate for a unified theory of all fundamental physical forces and elementary particles. The discovery of dualities and of important tools such as D-branes, has greatly reinforced this point of view. This document gathers the papers of 9 lectures: 1) supergravity, 2) supersymmetric gauge theories, 3) an introduction to duality symmetries, 4) large N field theories and gravity, 5) D-branes on the conifold and N = 1 gauge/gravity dualities, 6) de Sitter space, 7) string compactification with N = 1 supersymmetry, 8) open strings and non-commutative gauge theories, and 9) condensates near the Argyres-Douglas point in SU(2) gauge theory with broken N = 2 supersymmetry, and of 8 seminars: 1) quantum field theory with extra dimensions, 2) special holonomy spaces and M-theory, 3) four dimensional non-critical strings, 4) U-opportunities: why ten equal to ten?, 5) exact answers to approximate questions - non-commutative dipoles, open Wilson lines and UV-IR duality, 6) open-string models with broken supersymmetry, 7) on a field theory of open strings, tachyon condensation and closed strings, and 8) exceptional magic. (A.C.)

Bachas, C. [Laboratoire de Physique Theorique, ENS, 75 - Paris (France); Bilal, A. [Institut de Physique, Universite de Neuchatel, (Switzerland); Douglas, M. [New Jersey University, Dept. of Physics and Astronomy, Piscataway, NJ (United States); Nekrasov, N. [IHES, Institut des Hautes Etudes Scientifiques, 91 - Bures sur Yvette (France); David, F. [CEA Saclay, Service de Physique Theorique, 91 - Gif-sur-Yvette (France)

2002-07-01

203

Gauge Model Based on Group G × SU(2)

International Nuclear Information System (INIS)

We present a model of gauge theory based on the symmetry group G × SU(2) where G is the gravitational gauge group and SU(2) is the internal group of symmetry. We employ the spacetime of four-dimensional Minkowski, endowed with spherical coordinates, and describe the gauge fields by gauge potentials. The corresponding strength field tensors are calculated and the field equations are written. A solution of these equations is obtained for the case that the gauge potentials have a particular form with spherical symmetry. The solution for the gravitational potentials induces a metric of Schwarzschild type on the gravitational gauge group space

204

Gauge Defect Networks in Two-Dimensional CFT

An interpretation of the gauge anomaly of the two-dimensional multi-phase sigma model is presented in terms of an obstruction to the existence of a topological defect network implementing a local trivialisation of the gauged sigma model.

Suszek, Rafa? R

2013-01-01

205

Gravitational instantons and fluxes from M/F-theory on Calabi-Yau fourfolds

We compactify four-dimensional N=1 gauged supergravity theories on a circle including fluxes for shift-symmetric scalars. Four-dimensional Taub-NUT gravitational instantons universally correct the three-dimensional superpotential in the absence of fluxes. In the presence of fluxes these Taub-NUT instanton contributions are no longer gauge-invariant. Invariance can be restored by gauge-instantons on top of Taub-NUT instantons. We establish the embedding of this scenario into M-theory. Circle fluxes and gaugings arise from a restricted class of M-theory four-form fluxes on a resolved Calabi-Yau fourfold. The M5-brane on the base of the elliptic fourfold dualizes into the universal Taub-NUT instanton. In the presence of fluxes this M5-brane is anomalous. We argue that anomaly-free contributions arise from involved M5-brane geometries dual to gauge-instantons on top of Taub-NUT instantons. Adding a four-dimensional superpotential to the gravitational instanton corrections leads to three-dimensional Anti-de Sitter vacua at stabilized compactification radius. We comment on the possibility to uplift these M-theory vacua, and to tunnel to four-dimensional F-theory vacua.

Grimm, Thomas W.; Savelli, Raffaele

2012-01-01

206

Energy Technology Data Exchange (ETDEWEB)

We present new techniques for finding anomaly-free sets of fermions. Although the anomaly cancellation conditions typically include cubic equations with integer variables that cannot be solved in general, we prove by construction that any chiral set of fermions can be embedded in a larger set of fermions which is chiral and anomaly-free. Applying these techniques to extensions of the Standard Model, we find anomaly-free models that have arbitrary quark and lepton charges under an additional U(1) gauge group.

Batra, Puneet; /Argonne; Dobrescu, Bogdan A.; /Fermilab; Spivak, David; /UC, Berkeley, Math. Dept.

2005-10-01

207

International Nuclear Information System (INIS)

The innermost stable circular orbit (ISCO) delimits the transition from circular orbits to those that plunge into a black hole. In the test-mass limit, well-defined ISCO conditions exist for the Kerr and Schwarzschild spacetimes. In the finite-mass case, there are a large variety of ways to define an ISCO in a post-Newtonian (PN) context. Here I generalize the gauge-invariant ISCO condition of Blanchet and Iyer [Classical Quantum Gravity 20, 755 (2003)] to the case of spinning (nonprecessing) binaries. The Blanchet-Iyer ISCO condition has two desirable and unexpected properties: (1) it exactly reproduces the Schwarzschild ISCO in the test-mass limit, and (2) it accurately approximates the recently calculated shift in the Schwarzschild ISCO frequency due to the conservative-piece of the gravitational self-force [L. Barack and N. Sago, Phys. Rev. Lett. 102, 191101 (2009)]. The generalization of this ISCO condition to spinning binaries has the property that it also exactly reproduces the Kerr ISCO in the test-mass limit (up to the order at which PN spin corrections are currently known). The shift in the ISCO due to the spin of the test-particle is also calculated. Remarkably, the gauge-invariant PN ISCO condition exactly reproduces the ISCO shift predicted by the Papapetrou equations for a fully relativistic spinning particle. It is surprising that an analysis of the stability of the standard PN equations of motion is able (without any form of 'resummation') to accuratelut any form of 'resummation') to accurately describe strong-field effects of the Kerr spacetime. The ISCO frequency shift due to the conservative self-force in Kerr is also calculated from this new ISCO condition, as well as from the effective-one-body Hamiltonian of Barausse and Buonanno [Phys. Rev. D 81, 084024 (2010)]. These results serve as a useful point of comparison for future gravitational self-force calculations in the Kerr spacetime.

208

Radio-metric Doppler tracking data received from the Pioneer 10 and 11 spacecraft from heliocentric distances of 20-70 AU has consistently indicated the presence of a small, anomalous, blue-shifted frequency drift uniformly changing with a rate of ~6 x 10^{-9} Hz/s. Ultimately, the drift was interpreted as a constant sunward deceleration of each particular spacecraft at the level of a_P = (8.74 +/- 1.33) x 10^{-10} m/s^2. This apparent violation of the Newton's gravitational inverse-square law has become known as the Pioneer anomaly; the nature of this anomaly remains unexplained. In this review, we summarize the current knowledge of the physical properties of the discovered effect and the conditions that led to its detection and characterization. We review various mechanisms proposed to explain the anomaly and discuss the current state of efforts to determine its nature. A comprehensive new investigation of the anomalous behavior of the two Pioneers has begun recently. The new efforts rely on the much-extend...

Turyshev, Slava G

2010-01-01

209

Directory of Open Access Journals (Sweden)

Full Text Available Congenital anomalies in conjunction with intrauterine growth restriction account for 50-60% of fetal mortality. This article describes major birth defects by systems; most can be diagnosed by ultrasound while others cannot. Some anomalies develop later in pregnancy and in some cases sonographic examination may suggest the presence of a nonexistent abnormality. Incidence, etiology and risk factors of congenital malformations are described, as well as the importance and characteristics of prenatal diagnosis and prevention through folic acid supplementation in the diet.

Bernardita Donoso Bernales

2012-10-01

210

Corrections to Schwarzschild Solution in Noncommutative Gauge Theory of Gravity

A deformed Schwarzschild solution in noncommutative gauge theory of gravitation is obtained. The gauge potentials (tetrad fields) are determined up to the second order in the noncommutativity parameters $\\Theta^{\\mu\

Chaichian, M; Zet, G

2008-01-01

211

Anomaly Mediation in Local Effective Theories

The phenomenon known as "anomaly mediation" can be understood in a variety of ways. Rather than an anomaly, certain gaugino bilinear terms are required by local supersymmetry and gauge invariance (the derivation of these terms is in some cases related to anomalies in scale invariance or $R$ symmetries). We explain why the gaugino bilinear is required in supersymmetric gauge theories with varying number of colors and flavors. By working in the Higgs phase, gauging a flavor group, or working below the scale of gaugino condensation, each of these theories has a local effective description in which we can identify the bilinear term, establishing its necessity in the microscopic theory. For example, in theories that exhibit gaugino condensation, the potential in the very low energy theory is supersymmetric precisely due to the relation between the nonperturbative superpotential and the gaugino bilinear terms. Similarly, the gravitino mass appears from its coupling to the gaugino bilinear.

Dine, Michael

2013-01-01

212

Relation between anomaly in type-I superstring and anomaly in its effective theory

International Nuclear Information System (INIS)

We explicitly calculate the hexagon and heptagon (covariant) gauge anomaly including the precise numerical coefficients in type-I open superstring. The calculation is performed by using the Pauli-Villars regularization on the basis of the stringy Ward identity, which is an assumption weaker than the cancelled propagator argument. We show that the anomalies in the effective theory are realized as the zero slope limit (?' ? 0) of the string anomalies in a very non-trivial way in the present calculational scheme. This non-trivial realization in higher point (n ? 8) anomalies is also discussed. (author)

213

Energy Technology Data Exchange (ETDEWEB)

We discuss gravitational backgrounds where supersymmetry is broken at the end of a warped throat, and the SUSY-breaking is transmitted to the Standard Model via gauginos which live in (part of) the bulk of the throat geometry. We find that the leading effect arises from splittings of certain 'messenger mesons,' which are adjoint KK-modes of the D-branes supporting the Standard Model gauge group. This picture is a gravity dual of a strongly coupled field theory where SUSY is broken in a hidden sector and transmitted to the Standard Model via a relative of semi-direct gauge mediation.

Benini, Francesco; /Princeton U.; Dymarsky, Anatoly; /Stanford U., ITP; Franco, Sebastian; /Santa Barbara, KITP; Kachru, Shamit; Simic, Dusan; /Stanford U., ITP /SLAC; Verlinde, Herman; /Princeton, Inst. Advanced Study

2009-06-19

214

Black hole spectra in holography: consequences for equilibration of dual gauge theories

Energy gap in the spectrum of equilibrium states of interacting system, along with ability to continuously excite the system inside this gap, leads to violation of the ergodicity hypothesis. We explore this in the framework of gauge theory/string theory correspondence. We study the spectrum of static black holes in Pilch-Warner geometry. These black holes are holographically dual to equilibrium states of strongly coupled $SU(N)$ ${\\cal N}=2^*$ gauge theory plasma on $S^3$ in the planar limit. We find that there is no energy gap in the black hole spectrum. Thus, there is a priory no obstruction for equilibration of arbitrary low-energy states in the theory via a small black hole gravitational collapse. The latter is contrasted with phenomenological examples of holography with dual four-dimensional CFTs having non-equal central charges in the stress-energy tensor trace anomaly.

Buchel, Alex

2015-01-01

215

Connections between Schwinger terms and anomalies

International Nuclear Information System (INIS)

We present examples of a new type of Schwinger terms appearing in commutators of energy-momentum tensor. We demonstrate them in two-dimensional flat Minkowski space. The Schwinger terms which correspond to gravitational anomaly appear in different places from those of conformal anomaly. Nevertheless, they still preserve the Jacobi identity. We also discuss the relation between anomalies and the Schwinger terms. In any-dimensional curved space-time Faddeev's cohomological technique works well. Therefore we can derive the Schwinger terms in curved space-time. (author)

216

The Trace Anomaly and Dynamical Vacuum Energy in Cosmology

The trace anomaly of conformal matter implies the existence of massless scalar poles in physical amplitudes involving the stress-energy tensor. These poles may be described by a local effective action with massless scalar fields, which couple to classical sources, contribute to gravitational scattering processes, and can have long range gravitational effects at macroscopic scales. In an effective field theory approach, the effective action of the anomaly is an infrared relev...

Mottola, Emil

2010-01-01

217

On SU(2) anomaly and Majorana fermions

In this paper a loophole in the SU(2) gauge anomaly is presented. It is shown that using several topological tools a theory can be designed that implements the quantization of a single Weyl doublet anomaly free while keeping the non-abelian character of the particle in the theory. This opens the perspective for non-Abelian statistics of deconfined particle like objects in 3+1 dimensions and for applications in Quantum Computing. Moreover, if this loophole cannot be closed, old arguments related to anomaly cancelations must be reviewed.

Patrascu, Andrei

2015-01-01

218

Poincare gauge gravity: selected topics

In the gauge theory of gravity based on the Poincare group (the semidirect product of the Lorentz group and the spacetime translations) the mass (energy-momentum) and the spin are treated on an equal footing as the sources of the gravitational field. The corresponding spacetime manifold carries the Riemann-Cartan geometric structure with the nontrivial curvature and torsion. We describe some aspects of the classical Poincare gauge theory of gravity. Namely, the Lagrange-Noet...

Obukhov, Yuri N.

2006-01-01

219

Anomaly cancellations and compactifications in the SO(32) superstring theory

International Nuclear Information System (INIS)

Some aspects of anomaly cancellations and possible compactifications in the SO(32) superstring theory are discussed. A low-energy nonsemisimple gauge group often results from compactification. It requires that the massive modes of Kaluza-Klein space contribute to the gauge and mixed anomalies in four dimensions to implement the cancellations achieved in ten dimensions. Possible obstructions to compactifications due to surface terms are pointed out

220

Energy-Momentum and Gauge Conservation Laws

We treat energy-momentum conservation laws as particular gauge conservation laws when generators of gauge transformations are horizontal vector fields on fibre bundles. In particular, the generators of general covariant transformations are the canonical horizontal prolongations of vector fields on a world manifold. This is the case of the energy-momentum conservation laws in gravitation theories. We find that, in main gravitational models, the corresponding energy-momentum f...

Giachetta, G.; Mangiarotti, L.; Sardanashvily, G.

1998-01-01

221

Affine Defects and Gravitation

We argue that the structure general relativity (GR) as a theory of affine defects is deeper than the standard interpretation as a metric theory of gravitation. Einstein-Cartan theory (EC), with its inhomogenous affine symmetry, should be the standard-bearer for GR-like theories. A discrete affine interpretation of EC (and gauge theory) yields topological definitions of momentum and spin (and Yang Mills current), and their conservation laws become discrete topological identities. Considerations from quantum theory provide evidence that discrete affine defects are the physical foundation for gravitation.

Petti, R J

2014-01-01

222

New insight into BRST anomalies in superstring theory

International Nuclear Information System (INIS)

Based on the extended BRST formalism of Batalin, Fradkin and Vilkovisky, we perform a general algebraic analysis of the BRST anomalies in superstring theory of Neveu-Schwarz-Ramond. Consistency conditions on the BRST anomalies are completely solved. The genuine super-Virasoro anomaly is identified with the essentially unique solution to the consistency condition without any reference to a particular gauge for the 2D supergravity fields. In a configuration space where metric and gravitino fields are properly constructed, the general form of the super-Weyl anomaly is obtained from the super-Virasoro anomaly as its descendant. We give a novel local action of super-Liouville type, which plays a role of Wess-Zumino-Witten term shifting the super-Virasoro anomaly into the super-Weyl anomaly. These results reveal a hierarchical relationship in the BRST anomalies. ((orig.))

223

Modern on-shell methods allow us to construct both the classical and quantum S-matrix for a large class of theories, without utilizing knowledge of the interacting Lagrangian. It was recently shown that the same applies for chiral gauge theories, where the constraints from anomaly cancelation can be recast into the tension between unitarity and locality, without any reference to gauge symmetry. In this paper, we give a more detailed exploration, for chiral QED and QCD. We study the rational terms that are mandated by locality, and show that the factorization poles of such terms reveal a new particle in the spectrum, the Green-Schwarz two-from. We further extend the analysis to six-dimensional gravity coupled to chiral matter, including self-dual two-forms for which covariant actions generically do not exist. Despite this, the on-shell methods define the correct quantum S-matrix by demonstrating that locality of the one-loop amplitude requires combination of chiral matter that is consistent with that of anomal...

Chen, Wei-Ming; McGady, David A

2014-01-01

224

The innermost stable circular orbit (ISCO) delimits the transition from circular orbits to those that plunge into a black hole. In the test-mass limit, well-defined ISCO conditions exist for the Kerr and Schwarzschild spacetimes. In the finite-mass case, there are a large variety of ways to define an ISCO in a post-Newtonian (PN) context. Here I generalize the gauge-invariant ISCO condition of Blanchet & Iyer (2003) to the case of spinning (non-precessing) binaries. The Blanchet-Iyer ISCO condition has two desirable and unexpected properties: (1) it exactly reproduces the Schwarzschild ISCO in the test-mass limit, and (2) it accurately approximates the recently-calculated shift in the Schwarzschild ISCO frequency due to the conservative-piece of the gravitational self-force [Barack & Sago (2009)]. The generalization of this ISCO condition to spinning binaries has the property that it also exactly reproduces the Kerr ISCO in the test-mass limit (up to the order at which PN spin corrections are currentl...

Favata, Marc

2010-01-01

225

Solution of the de-Sitter gauge theory

International Nuclear Information System (INIS)

The de-Sitter gauge theory with SO(1,4) as symmetry group is considered. A real parameter that determines a deformation of the Lie algebra of this group is introduced. It determines the cosmological constant of the model. When this parameter vanishes we obtain the Poincare gauge theory of the gravitational field without cosmological constant. Solutions of the gravitational field equations are obtained considering a model with spherically symmetric gauge potentials. In particular, the case of gravitational field created by a point-like mass having a constant electric charge is considered. The duality property is also studied considering a magnetic monopole with non-null mass as source of the gravitational field. Our de-Sitter gauge theory of gravitation has the Minkowski space-time as base manifold and its geometrical structure is not affected anymore by the gauge transformations. (author)

226

Relevance of induced gauge interactions in decoherence

International Nuclear Information System (INIS)

Decoherence in quantum cosmology is shown to occur naturally in the presence of induced geometric gauge interactions associated with particle production. A new ''gauge'' - variant form of the semiclassical Einstein equations is also presented which makes the non-gravitating character of the vacuum polarization energy explicit. (author). 20 refs

227

Yang's pure space equations (C.N. Yang, Phys. Rev. Lett. v.33, p.445 (1974)) generalize Einstein's gravitational equations, while coming from gauge theory. We study these equations from a number of vantage points: summarizing the work done previously, comparing them with the Einstein equations and investigating their properties. In particular, the initial value problem is discussed and a number of results are presented for these equations with common energy-momentum tensors.

Guilfoyle, B S; Guilfoyle, Brendan S.; Nolan, Brien C.

1998-01-01

228

The Index and Axial Anomaly of a lattice Dirac operator

A remarkable feature of a lattice Dirac operator is discussed. Unlike the Dirac operator for massless fermions in the continuum, this Ginsparg-Wilson lattice Dirac operator does not possess topological zero modes for any topologically-nontrivial background gauge fields, even though it is exponentially-local, doublers-free, and reproduces correct axial anomaly for topologically-trivial gauge configurations.

Chiu, Ting-wai

2001-01-01

229

QCD Flux Tubes and Anomaly Inflow

We apply the Callan-Harvey anomaly inflow mechanism to the study of QCD (chromoelectric) flux tubes, quark (pair)-creation and chiral magnetic effect, using new variables from the Cho-Faddeev-Niemi decomposition of the gauge potential. A phenomenological description of chromoelectric flux tubes is obtained by studying a gauged Nambu-Jona-Lasinio effective Lagrangian, derived from the original QCD Lagrangian. At the quantum level, quark condensates in the QCD vacuum may form a vortex-like structure in a chromoelectric flux tube. Quark zero modes trapped in the vortex are chiral and lead to a two-dimensional gauge anomaly. To cancel it an effective Chern-Simons coupling is needed and hence a topological charge density term naturally appears.

Xiong, Chi

2013-01-01

230

Emergent gravity and chiral anomaly in Dirac semimetals in the presence of dislocations

We consider the recently discovered Dirac semimetals with two Dirac points $\\pm{\\bf K}$. In the presence of elastic deformations each fermion propagates in a curved space, whose metric is defined by the expansion of the effective Hamiltonian near the Dirac point. Besides, there is the emergent electromagnetic field that is defined by the shift of the Dirac point. We consider the case, when the deformations are caused by the dislocations. The dislocation carries singular torsion and the quantized flux of emergent magnetic field. Both torsion singularity and emergent magnetic flux may be observed in the scattering of quasiparticles on the dislocation due to Stodolsky and Aharonov - Bohm effects. We discuss quantum anomalies in the quasiparticle currents in the presence of emergent gauge and gravitational fields and the external electromagnetic field. In particular, it is demonstrated, that in the presence of external electric field the quasiparticles/holes are pumped from vacuum along the dislocation. The appea...

Zubkov, M A

2015-01-01

231

Gaugino-Assisted Anomaly Mediation

International Nuclear Information System (INIS)

We present a model of supersymmetry breaking mediated through a small extra dimension. Standard model matter multiplets and a supersymmetry-breaking (or ''hidden'') sector are confined to opposite four-dimensional boundaries while gauge multiplets live in the bulk. The hidden sector does not contain a singlet and the dominant contribution to gaugino masses is via anomaly-mediated supersymmetry breaking. Scalar masses get contributions from both anomaly mediation and a tiny hard breaking of supersymmetry by operators on the hidden-sector boundary. These operators contribute to scalar masses at one loop and in most of parameter space, their contribution dominates. Thus it is easy to make all squared scalar masses positive. As no additional fields or symmetries are required below the Planck scale, we consider this the simplest working model of anomaly mediation. The gaugino spectrum is left untouched and the phenomenology of the model is roughly similar to anomaly mediated supersymmetry breaking with a universal scalar mass added. We identify the main differences in the spectrum between this model and other approaches. We also discuss mechanisms for generating the ? term and constraints on additional bulk fields. (author)

232

A lattice construction of chiral gauge theories

International Nuclear Information System (INIS)

We formulate chiral gauge theories non-perturbatively, using two different cutoffs for the fermions and gauge bosons. We use a lattice with spacing b to regulate the gauge fields in standard fashion, while computing the chiral fermion determinant on a finer lattice with spacing f 2/b2) by a one-loop subtraction of calculable local gauge field counterterms. We show that the only obstruction to this procedure is the presence of an uncancelled gauge anomaly among the fermion representations. We conclude that for practical purposes, it suffices to choose f/b similar b/L, where L4 is the physical volume of the system. In our construction it is simple to prove the Adler-Bardeen theorem for anomalies in global currents to all orders. The related subject of fermion-number violation is also studied. Finally, we discuss the prospects for improving the efficiency of our algorithm. (orig.)

233

Trace anomalies and QED in curved space

International Nuclear Information System (INIS)

It is shown, for massless QED in a weakly curved background, how to obtain full information about the trace anomaly in perturbation theory, including the ''topological'' term in the gravitational part of the anomaly. The arguments used follow as straightforward adaptations of those presented for lambdaPHI4 theory, and rely on a renormalisation-group analysis combined with strong connections between renormalisability of the curved space theory, finiteness of the energy-momentum tensor, and the use of Normal Products. The first non-zero ?-dependent terms appear at O(?2) for the topological part, and at O(?3) for the non-conformal R2 part of the anomaly. Both values can be deduced via the renormalisation-group arguments from simple flat space Feynman diagrams. A direct 3-loop calculation confirms the vanishing of the O(?2) term in the R2 anomaly. The analysis follows the scalar theory closely, while being simpler in many places. (author)

234

A New Anomaly Matching Condition?

We formulate ``Witten'' matching conditions for confining gauge theories. The conditions are analogous to 't Hooft's, but involve Witten's global SU(2) anomaly. Using a group theoretic result of Geng, Marshak, Zhao and Okubo, we show that if the fourth homotopy group of the flavor group $H$ is trivial ($\\Pi_4(H) = 0$) then realizations of massless composite fermions that satisfy the 't Hooft conditions also satisfy the Witten conditions. If $\\Pi_4 (H)$ is nontrivial, the new matching conditions can yield additional information about the low energy spectrum of the theory. We give a simple physical proof of Geng, et. al.'s result.

Bhansali, V; Bhansali, Vineer; Hsu, Stephen D.H.

1993-01-01

235

6d, N=(1,0) Coulomb Branch Anomaly Matching

6d QFTs are constrained by the analog of 't Hooft anomaly matching: all anomalies for global symmetries and metric backgrounds are constants of RG flows, and for all vacua in moduli spaces. We discuss an anomaly matching mechanism for 6d N=(1,0) theories on their Coulomb branch. It is a global symmetry analog of Green-Schwarz-West-Sagnotti anomaly cancellation, and requires the apparent anomaly mismatch to be a perfect square, $\\Delta I_8={1\\over 2}X_4^2$. Then $\\Delta I_8$ is cancelled by making $X_4$ an electric / magnetic source for the tensor multiplet, so background gauge field instantons yield charged strings. This requires the coefficients in $X_4$ to be integrally quantized. We illustrate this for N=(2,0) theories. We also consider the N=(1,0) SCFTs from N small $E_8$ instantons, verifying that the recent result for its anomaly polynomial fits with the anomaly matching mechanism.

Intriligator, Kenneth

2014-01-01

236

A lattice formulation of chiral gauge theories

International Nuclear Information System (INIS)

The authors present a method for formulating gauge theories of chiral fermions in lattice field theory. The method makes use of a Wilson mass to remove doublers. Gauge invariance is then restored by modifying the theory in two ways: the magnitude of the fermion determinant is replaced with the square root of the determinant for a fermion with vector-like couplings to the gauge field; a double limit is taken in which the lattice spacing associated with the fermion field is taken to zero before the lattice spacing associated with the gauge field. The method applies only to theories whose fermions are in an anomaly-free representation of the gauge group. They also present a related technique for computing matrix elements of operators involving fermion fields. Although the analyses of these methods are couched in weak-coupling perturbation theory, it is argued that computational prescriptions are gauge invariant in the presence of a nonperturbative gauge-field configuration

237

Adding gauge fields to Kaplan's fermions

We experiment with adding dynamical gauge field to Kaplan (defect) fermions. In the case of U(1) gauge theory we use an inhomogenous 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. This is an uuencoded ps-file. Use 'uudecode hepchiral.ps' to produce the psfile.

Blum, T; Leo Kärkkäinen

1994-01-01

238

Recent developments in the path integral approach to anomalies

International Nuclear Information System (INIS)

After a brief summary of the path integral approach to anomalous identities, some of the recent developments in this approach are discussed. The topics discussed include (i) Construction of the effective action by means of the covariant current, (ii) Gauss law constraint in anomalous gauge theories, (iii) Path integral approach to anomalies in superconformal transformations, (iv) Conformal and ghost number anomalies in string theory in analogy with the instanton calculation, (v) Covariant local Lorentz anomaly and its connection with the mathematical construction of the consistent anomaly. (author)

239

Quaternion gauge theory of dyonic fields

International Nuclear Information System (INIS)

Outlining the idea of quaternion non-Abelian gauge formalism and that of the structural symmetry between generalized fields of dyons and gravito-dyons, it is shown that this formulation characterizes the Abelian and non-Abelian structure of dyons in terms of pure real and imaginary unit quaternions. Extending this formalism to the case of gravito-dyons it has been shown that pure imaginary unit quaternions advocate the curvature in the theory of gravito-dyons and hence the SL(2,c) gauge group of gravitation plays the same role as that of SU(2) gauge group does in non-Abelian gauge theory. Furthermore, we have unified the theories of electromagnetism and gravitation in terms of single parameter ? by means of quaternion-gauge formalism and the corresponding field equations have also been derived in a unique and consistent way. (author)

240

Axial anomalies of Lifshitz fermions

Energy Technology Data Exchange (ETDEWEB)

We compute the axial anomaly of a Lifshitz fermion theory with anisotropic scaling z = 3 which is minimally coupled to geometry in 3+1 space-time dimensions. We find that the result is identical to the relativistic case using path integral methods. An independent verification is provided by showing with spectral methods that the {eta}-invariant of the Dirac and Lifshitz fermion operators in three dimensions are equal. Thus, by the integrated form of the anomaly, the index of the Dirac operator still accounts for the possible breakdown of chiral symmetry in non-relativistic theories of gravity. We apply this framework to the recently constructed gravitational instanton backgrounds of Horava-Lifshitz theory and find that the index is non-zero provided that the space-time foliation admits leaves with harmonic spinors. Using Hitchin's construction of harmonic spinors on Berger spheres, we obtain explicit results for the index of the fermion operator on all such gravitational instanton backgrounds with SU(2) x U(1) isometry. In contrast to the instantons of Einstein gravity, chiral symmetry breaking becomes possible in the unimodular phase of Horava-Lifshitz theory arising at {lambda} = 1/3 provided that the volume of space is bounded from below by the ratio of the Ricci to Cotton tensor couplings raised to the third power. Some other aspects of the anomalies in non-relativistic quantum field theories are also discussed. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Bakas, I. [Department of Physics, University of Patras (Greece); Luest, D. [Max-Planck-Institut fuer Physik, Muenchen (Germany); Arnold-Sommerfeld-Center fuer Theoretische Physik, Department fuer Physik, Ludwig-Maximilians-Universitaet Muenchen (Germany); Theory Division, Department of Physics, CERN, Geneva (Switzerland)

2011-10-15

241

International Nuclear Information System (INIS)

The fundamental laws of nature may be truely random, or they may be so complicated that a random description is adequate. With this philosophy we examine various ways in which a lattice gauge theory (at the Planck scale) can be generalized. Without here giving up a regular lattice structure (which we really ought to do) we consider two generalizations. Making the action (quenched) random has the effect that the gauge group tends to break down and some gauge bosons become massive, unless the gauge group has special properties: no noncentral corners in the geometry of conjugacy classes and furthermore a connected center. Making the concept of gauge transformation more general has a symmetry breaking effect for groups with outer automorphisms. A study of SU5-breaking in the context of the first breakdown mechanism (D. Bennett, E. Buturovic and H. B. Nielsen) is shortly reviewed. (orig.)

242

Schwinger model and its axial anomaly

International Nuclear Information System (INIS)

The Schwinger model (quantum electrodynamics with massless fermions in one spatial dimension) is solved, supposing that space is a circle. This clarifies aspects of the usual version of the model, where space is a line, without changing the physics. The Hamiltonian formalism is used. On a circle, an abelian gauge field has one physical degree of freedom, and the gauge covariant Dirac operator, which couples the fermions to this degree of freedom, exhibits spectral flow. The relationship between the spectral flow and the axial anomaly is explained. Some variants of the Schwinger model are also discussed

243

Kohn Anomalies in Superconductors

I present the detailed behavior of phonon dispersion curves near momenta which span the electronic Fermi sea in a superconductor. I demonstrate that an anomaly, similar to the metallic Kohn anomaly, exists in a superconductor's dispersion curves when the frequency of the phonon spanning the Fermi sea exceeds twice the superconducting energy gap. This anomaly occurs at approximately the same momentum but is {\\it stronger} than the normal-state Kohn anomaly. It also survives at finite temperature, unlike the metallic anomaly. Determination of Fermi surface diameters from the location of these anomalies, therefore, may be more successful in the superconducting phase than in the normal state. However, the superconductor's anomaly fades rapidly with increased phonon frequency and becomes unobservable when the phonon frequency greatly exceeds the gap. This constraint makes these anomalies useful only in high-temperature superconductors such as $\\rm La_{1.85}Sr_{.15}CuO_4$.

Flatté, M E

1993-01-01

244

Lymphatic Malformation; Generalized Lymphatic Anomaly (GLA); Central Conducting Lymphatic Anomaly; CLOVES Syndrome; Gorham-Stout Disease ("Disappearing Bone Disease"); Blue Rubber Bleb Nevus Syndrome; Kaposiform Lymphangiomatosis; Kaposiform Hemangioendothelioma/Tufted Angioma; Klippel-Trenaunay Syndrome; Lymphangiomatosis

2015-03-21

245

S-matrix theory for gravitational field

International Nuclear Information System (INIS)

Major results of the investigation conducted on the quantum theory of the gravitational field and reported to the conference are summarized. The S matrix has been constructed in the most general class of gauges including relativistic ones. The causes of the failure to apply the proper-time regularization technique to gravitational interaction are considered. The corrected and improved proper-time method makes it possible to obtain the universal expression for one-loop divergences in and arbitrary system of gravitational fields. Under the assumption of mass-shell renormalizability the quantum theory of the gravitational field is asymptotically free

246

A first look at Weyl anomalies in shape dynamics

International Nuclear Information System (INIS)

One of the more popular objections towards shape dynamics is the suspicion that anomalies in the spatial Weyl symmetry will arise upon quantization. The purpose of this short paper is to establish the tools required for an investigation of the sort of anomalies that can possibly arise. The first step is to adapt to our setting Barnich and Henneaux's formulation of gauge cohomology in the Hamiltonian setting, which serve to decompose the anomaly into a spatial component and time component. The spatial part of the anomaly, i.e., the anomaly in the symmetry algebra itself ([?, ?] ? ? instead of vanishing) is given by a projection of the second ghost cohomology of the Hamiltonian BRST differential associated to ?, modulo spatial derivatives. The temporal part, [?, H] ? ? is given by a different projection of the first ghost cohomology and an extra piece arising from a solution to a functional differential equation. Assuming locality of the gauge cohomology groups involved, this part is always local. Assuming locality for the gauge cohomology groups, using Barnich and Henneaux's results, the classification of Weyl cohomology for higher ghost numbers performed by Boulanger, and following the descent equations, we find a complete characterizations of anomalies in 3+1 dimensions. The spatial part of the anomaly and the first component of the temporal anomaly are always local given these assumptions even in shape dynamics. The part emerging from the solution of the functional differential equations explicitly involves the shape dynamics Hamiltonian, and thus might be non-local. If one restricts this extra piece of the temporal anomaly to be also local, then overall no Weyl anomalies, either temporal or spatial, emerge in the 3+1 case

247

Wodzicki residue and anomalies of current algebras

International Nuclear Information System (INIS)

The commutator anomalies (Schwinger terms) of current algebras in 3 + 1 dimensions are computed in terms of the Wodzicki residue of pseudo-differential operators; the result can be written as a (twisted) Radul 2-cocyle for the Lie algebra of PSDO's. The construction of the (second quantized) current algebra is closely related to a geometric renormalization of the interaction Hamiltonian HI = j?A? in gauge theory. (orig.)

248

Anomaly extraction from the path integral

International Nuclear Information System (INIS)

Fujikawa's recently proposed derivation of the anomaly from the path integral is examined. It is attempted to give a better understanding of his work. In particular, evasions of his result are discussed; for example it is shown how chiral U(1) axial invariance can be maintained by employing a gauge variant regularization prescription. A brief connection with the point-splitting method is also made. (orig.)

249

Anomaly equations and the persistent mass condition

International Nuclear Information System (INIS)

Vector SU(Nsub(c)) gauge theories with nsub(f) flavors in the fundamental representation are considered. We prove that if the persistent mass condition is assumed, the two anomaly equations are identical and flavor independent for nsub(f)>=3. Integer solutions exist only for nsub(f)=2. The necessity of a separate discussion for 2<=nsub(f)<=Nsub(c) is explained. (author)

250

Tracheobronchial Branching Anomalies

Energy Technology Data Exchange (ETDEWEB)

There are various congenital anomalies with respect to the number, length, diameter, and location of tracheobronchial branching patterns. The tracheobronchial anomalies are classified into two groups. The first one, anomalies of division, includes tracheal bronchus, cardiac bronchus, tracheal diverticulum, pulmonary isomerism, and minor variations. The second one, dysmorphic lung, includes lung agenesis-hypoplasia complex and lobar agenesis-aplasia complex

Hong, Min Ji; Kim, Young Tong; Jou, Sung Shick [Soonchunhyang University, Cheonan Hospital, Cheonan (Korea, Republic of); Park, A Young [Soonchunhyang University College of Medicine, Asan (Korea, Republic of)

2010-04-15

251

Upper bound for induced gravitation

International Nuclear Information System (INIS)

Given the assumption that G/sub ind.//sup ts-1/ from the Adler-Zee formula is positive, an explicit and rigorous upper bound is derived for it. For pure SU(N) gauge theory, (16?G)-12)(N2-1) ?/sub N//sup ts2/ is obtained, where ?/sub N/ is the mass scale. In general the bound (16?G)-12/144)C/sub psi/?2 obtained, where C/sub psi/ is the coefficient of the most singular anomaly contribution in x space, a constant easily determined by low-order perturbation theory for any gauge group

252

Probing Gravitational Dark Matter

So far all evidences of dark matter (DM) come from astrophysical and cosmological observations, due to the gravitational interactions of DM. It is possible that the true DM particle in the universe joins gravitational interactions only, but nothing else. Such a Gravitational DM (GDM) acts as a weakly interacting massive particle (WIMP), which is conceptually simple and attractive. In this work, we explore this direction by constructing the simplest scalar GDM particle $\\chi_s$. It is a $\\mathbb{Z}_2$ odd singlet under the standard model (SM) gauge group, and naturally joins the unique dimension-4 interaction with Ricci curvature, $\\xi_s\\chi_s^2{\\cal R}$, where $\\xi_s$ is the dimensionless nonminimal coupling. We demonstrate that this gravitational interaction $\\xi_s\\chi_s^2{\\cal R}$, together with Higgs-curvature nonminimal coupling term $\\xi_h H^\\dag H {\\cal R}$, induces effective couplings between $\\chi_s^2$ and SM fields which can account for the observed DM thermal relic abundance. We analyze the annihila...

Ren, Jing

2014-01-01

253

Probing gravitational dark matter

So far all evidences of dark matter (DM) come from astrophysical and cosmological observations, due to the gravitational interactions of DM. It is possible that the true DM particle in the universe joins gravitational interactions only, but nothing else. Such a Gravitational DM (GDM) may act as a weakly interacting massive particle (WIMP), which is conceptually simple and attractive. In this work, we explore this direction by constructing the simplest scalar GDM particle ?s. It is a Bbb Z2 odd singlet under the standard model (SM) gauge group, and naturally joins the unique dimension-4 interaction with Ricci curvature, ?s?s2Script R, where ?s is the dimensionless nonminimal coupling. We demonstrate that this gravitational interaction ?s?s2Script R, together with Higgs-curvature nonminimal coupling term ?hH†HScript R, induces effective couplings between ?s2 and SM fields, and can account for the observed DM thermal relic abundance. We analyze the annihilation cross sections of GDM particles and derive the viable parameter space for realizing the DM thermal relic density. We further study the direct/indirect detections and the collider signatures of such a scalar GDM. These turn out to be highly predictive and testable.

Ren, Jing; He, Hong-Jian

2015-03-01

254

Matching conditions and duality in N=1 SUSY gauge theories in the conformal window

We discuss duality in N=1 SUSY gauge theories in Seiberg's conformal window, (3N_c/2)

Kogan, I I; Vainshtein, A I; Kogan, Ian I; Shifman, Mikhail; Vainshtein, Arkady

1996-01-01

255

Effects of local mass anomalies in Eoetvoes-like experiments

International Nuclear Information System (INIS)

We consider in detail the effects of local mass anomalies in Eoetvoes-like experiments. It is shown that in the presence of an intermediate-range non-gravitational force, the dominant contributions to both the sign and magnitude of the Eoetvoes anomaly may come from nearby masses and not from the earth as a whole. This observation has important implications in the design and interpretation of future experiments, and in the formulation of unified theories incorporating new intermediate-range forces

256

Based on thermal equilibrium between the vacuum and its relevant excitations a model for cosmic inflation is presented. Due to a vacuum dominating, U(1) gauged inflaton field an inflationary regime can be reached without explicitly imposing slow-roll conditions. Thereby, nontrivial euclidean BPS saturation of the inflaton bans gravity from the field equations and masquerades the gauge symmetry as a $Z_{N+1}$ symmetry at the point where thermal equilibrium breaks down. Solving the vacuum dynamics of the gauge field in the inflaton background in the spirit of a Born-Oppenheimer approximation, a temperature dependent cosmological constant $\\La=\\La(T)$ is obtained. The $T$ dependence of $\\La$ competes with the black body radiation of the (massive) gauge field during cosmic expansion. This leads to (initial condition independent) inflation at some critical value of the inflaton amplitude. The model allows for a closed, noncollapsing universe with Planckian initial density, and hence it resolves the flatness proble...

Hofmann, Ralf; Hofmann, Ralf; Keil, Mathias Th.

2002-01-01

257

Schwarzschild-de-Sitter Solution in Quantum Gauge Theory of Gravity

International Nuclear Information System (INIS)

We use the theory based on the gravitational gauge group G to obtain a spherical symmetric solution of the field equations for the gravitational potentials on a Minkowski space-time. The gauge group G is defined and then we introduce the gauge-covariant derivative D?. The strength tensor of the gravitational gauge field is also obtained and a gauge-invariant Lagrangian including the cosmological constant is constructed. A model whose gravitational gauge potentials A??(x) have spherical symmetry, depending only on the radial coordinate r is considered and an analytical solution of these equations, which induces the Schwarzschild-de-Sitter metric on the gauge group space, is then determined. All the calculations have been performed by GR Tensor II computer algebra package, running on the Maple V platform, along with several routines that we have written for our model.

258

Differential formalism aspects of the gauge classical theories

International Nuclear Information System (INIS)

The classical aspects of the gauge theories are shown using differential geometry as fundamental tool. Somme comments are done about Maxwell Electro-dynamics, classical Yang-Mills and gravitation theories. (L.C.)

259

Gauged Wess-Zumino-Witten actions for generalized Poincaré algebras

If the Chern-Simons theory is the appropriate gauge theory for the gravitational interaction, then these theories must satisfy the correspondence principle, namely they must be related to General Relativity.

Salgado, S.; Izaurieta, F.; González, N.; Rubio, G.

2014-05-01

260

An explicit example of a tumbling gauge theory

International Nuclear Information System (INIS)

We present a class of two-dimensional models with a non-abelian gauge symmetry. In one model with gauge symmetry is dynamically broken by a fermion bilinear condensate in a 1/n expansion. We discuss the differences between a dynamical and elementary Higgs mechanism due to the presence of a non-abelian axial anomaly. (orig.)

261

Noncompact chiral U(1) gauge theories on the lattice

International Nuclear Information System (INIS)

A new, adiabatic phase choice is adopted for the overlap in the case of an infinite volume, noncompact Abelian chiral gauge theory. This gauge choice obeys the same symmetries as the Brillouin-Wigner (BW) phase choice, and, in addition, produces a Wess-Zumino functional that is linear in the gauge variables on the lattice. As a result, there are no gauge violations on the trivial orbit in all theories, consistent and covariant anomalies are simply related, and Berry's curvature now appears as a Schwinger term. The adiabatic phase choice can be further improved to produce a perfect phase choice, with a lattice Wess-Zumino functional that is just as simple as the one in continuum. When perturbative anomalies cancel, gauge invariance in the fermionic sector is fully restored. The lattice effective action describing an anomalous Abelian gauge theory has an explicit form, close to one analyzed in the past in a perturbative continuum framework

262

Anomalies in non-polynomial closed string field theory

Energy Technology Data Exchange (ETDEWEB)

The complete classical action for the non-polynomial closed string field theory was written down last year by the author and the Kyoto group. It successfully reproduces all closed string tree diagrams, but fails to reproduce modular invariant loop amplitudes. In this paper we show that the classical action is also riddled with gauge anomalies. Thus, the classical action is not really gauge invariant and fails as a quantum theory. The presence of gauge anomalies and the violation of modular invariance appear to be a disaster for the theory. Actually, this is a blessing in disguise. We show that by adding new non-polynomial terms to the action, we can simultaneously eliminate both the gauge anomalies and the modular-violating loop diagrams. We show this explicitly at the one loop level and also for an infinite class of p-puncture, genus-g amplitudes, making use of a series of non-trivial identities. The theory is thus an acceptable quantum theory. We comment on the origin of this strange link between local gauge anomalies and global modular invariance. (orig.).

Kaku, Michio (Institute for Advanced Study, Princeton, NJ (USA))

1990-11-01

263

Anomalies in non-polynomial closed string field theory

International Nuclear Information System (INIS)

The complete classical action for the non-polynomial closed string field theory was written down last year by the author and the Kyoto group. It successfully reproduces all closed string tree diagrams, but fails to reproduce modular invariant loop amplitudes. In this paper we show that the classical action is also riddled with gauge anomalies. Thus, the classical action is not really gauge invariant and fails as a quantum theory. The presence of gauge anomalies and the violation of modular invariance appear to be a disaster for the theory. Actually, this is a blessing in disguise. We show that by adding new non-polynomial terms to the action, we can simultaneously eliminate both the gauge anomalies and the modular-violating loop diagrams. We show this explicitly at the one loop level and also for an infinite class of p-puncture, genus-g amplitudes, making use of a series of non-trivial identities. The theory is thus an acceptable quantum theory. We comment on the origin of this strange link between local gauge anomalies and global modular invariance. (orig.)

264

This model shows the effect of gravitational attraction between two objects, demonstrating that gravitational forces are directly proportional to mass of each body, but inversely proportional to the square of the distance between the bodies. The model may be easily modified to demonstrate Coulomb's Law.

Charlotte Trout

265

Topological anomalies for Seifert 3-manifolds

We study globally supersymmetric 3d gauge theories on curved manifolds by describing the coupling of 3d topological gauge theories, with both Yang-Mills and Chern-Simons terms in the action, to background topological gravity. In our approach the Seifert condition for manifolds supporting global supersymmetry is elegantly deduced from the topological gravity BRST transformations. A cohomological characterization of the geometrical moduli which affect the partition function is obtained. In the Seifert context Chern-Simons topological (framing) anomaly is BRST trivial. We compute explicitly the corresponding local Wess-Zumino functional. As an application, we obtain the dependence on the Seifert moduli of the partition function of 3d supersymmetric gauge theory on the squashed sphere by solving the anomalous topological Ward identities, in a regularization independent way and without the need of evaluating any functional determinant.

Imbimbo, Camillo

2014-01-01

266

Matrix Models and Gravitational Corrections

We provide evidence of the relation between supersymmetric gauge theories and matrix models beyond the planar limit. We compute gravitational R^2 couplings in gauge theories perturbatively, by summing genus one matrix model diagrams. These diagrams give the leading 1/N^2 corrections in the large N limit of the matrix model and can be related to twist field correlators in a collective conformal field theory. In the case of softly broken SU(N) N=2 super Yang-Mills theories, we find that these exact solutions of the matrix models agree with results obtained by topological field theory methods.

Dijkgraaf, R; Temurhan, M; Dijkgraaf, Robbert; Sinkovics, Annamaria; Temurhan, Mine

2002-01-01

267

We use the 5D Extra Dimensional Force according to Basini-Capozziello-Ponce De Leon,Overduin-Wesson and Mashoon-Wesson-Liu Formalisms to study the behaviour of the Chung-Freese Superluminal BraneWorld compared to the Alcubierre Warp Drive and we arrive at some interesting results from the point of view of the Alcubierre ansatz although we used a diferent Shape Function f(rs) with a behaviour similar to the Natario Warp Drive. We introduce here the Casimir Warp Drive. We also demonstrate that in flat 5D Minkowsky Spacetime or weak Gravitational Fields we cannot tell if we live in a 5D or a 4D Universe according to Basini-Capozziello-Ponce De Leon,Overduin-Wesson and Mashoon-Wesson-Liu Dimensional Reduction but in the extreme conditions of Strong Gravitational Fields we demonstrate that the effects of the 5D Extra Dimension becomes visible and perhaps the study of the extreme conditions in Black Holes can tell if we live in a Higher Dimensional Universe. We use a 5D Maartens-Clarkson Schwarzschild Cosmic Black ...

Loup, Fernando

2007-01-01

268

Algebraic classification of Weyl anomalies in arbitrary dimensions.

Conformally invariant systems involving only dimensionless parameters are known to describe particle physics at very high energy. In the presence of an external gravitational field, the conformal symmetry may generalize to the Weyl invariance of classical massless field systems in interaction with gravity. In the quantum theory, the latter symmetry no longer survives: A Weyl anomaly appears. Anomalies are a cornerstone of quantum field theory, and, for the first time, a general, purely algebraic understanding of the universal structure of the Weyl anomalies is obtained, in arbitrary dimensions and independently of any regularization scheme. PMID:17678079

Boulanger, Nicolas

2007-06-29

269

Anomalies of BRS and anti-BRS ward-identities in N=1 supersymmetric theory

International Nuclear Information System (INIS)

The requirement of BRS and anti-BRS symmetries in N = 1 supersymmetric theory leads to Ward-identities independent of the gauge parameter. The cohomology conditions are immediately satisfied. This yields a supersymmetric formula of the chiral anomaly

270

From the viewpoint of the integral formalism of gauge gravitational theories, the path dependent gravitational phase factors define the Lorentz transformations between the local inertial coordinate systems of different positions. With this point we show that the spectral shifts in the curved spacetime, such as the gravitational and cosmological redshifts, can be understood as Doppler shifts. All these shifts are interpreted in a unified way as being originated from the relative motion of the free falling observers instantaneously static with the wave source and the receiver respectively. The gravitational phase factor of quantum systems in the curved spacetime is also discussed.

Li, Mingzhe

2014-01-01

271

International Nuclear Information System (INIS)

From the viewpoint of gauge gravitational theories, the path dependent gravitational phase factors define the Lorentz transformations between the local inertial coordinate systems of different positions. With this point we show that the spectral shifts in the curved spacetime, such as the gravitational and cosmological redshifts, can be understood as Doppler shifts. All these shifts are interpreted in a unified way as being originated from the relative motion of the free falling observers instantaneously static with the wave source and the receiver respectively. The gravitational phase factor of quantum systems in the curved spacetime is also discussed. (paper)

272

A Pseudospectral Method for Gravitational Wave Collapse

We present a new pseudospectral code, bamps, for numerical relativity written with the evolution of collapsing gravitational waves in mind. We employ the first order generalized harmonic gauge formulation. The relevant theory is reviewed and the numerical method is critically examined and specialized for the task at hand. In particular we investigate formulation parameters, gauge and constraint preserving boundary conditions well-suited to non-vanishing gauge source functions. Different types of axisymmetric twist-free moment of time symmetry gravitational wave initial data are discussed. A treatment of the axisymmetric apparent horizon condition is presented with careful attention to regularity on axis. Our apparent horizon finder is then evaluated in a number of test cases. Moving on to evolutions, we investigate modifications to the generalized harmonic gauge constraint damping scheme to improve conservation in the strong field regime. We demonstrate strong-scaling of our pseudospectral penalty code. We em...

Hilditch, David; Bruegmann, Bernd

2015-01-01

273

The Poland anomaly is usually a non-genetic malformation syndrome. This paper reports two second cousins who both had a typical left sided Poland anomaly, and this constitutes the first recorded case of this condition affecting more than one member of a family. Despite this, for the purposes of genetic counselling, the Poland anomaly can be regarded as a sporadic condition with an extremely low recurrence risk.

David, T. J.

1983-01-01

274

International Nuclear Information System (INIS)

We consider global anomalies for heterotic string theory formulated on orbifolds. The vanishing of certain characteristic glasses in group cohomology provides sufficient conditions for the absence of global anomalies. For abelian orbifolds level matching implies these cohomology conditions, so suffices for the absence of anomalies. For nonabelian orbifolds level matching does not suffice, and there are additional constraints. We give some examples to illustrate these new constraints. (orig.)

275

Two potentials, one gauge group: A possible geometrical motivation

International Nuclear Information System (INIS)

By studying the purely gravitational sector of a higher dimensional matter-gravity coupled theory, one can see that in the case of non-vanishing torsion the effective 4-dimensional theory exhibits two gauge potentials that transform under the action of a single gauge group. (Author)

276

Two potentials, one gauge group. A possible geometrical motivation

Energy Technology Data Exchange (ETDEWEB)

By studying the purely gravitational sector of a higher-dimensional matter-gravity coupled theory, one can see that in the case of nonvanishing torsion the effective 4-dimensional theory exhibits two gauge potentials that transform under the action of a single gauge group.

Doria, R.M.; Pombo, C.

1986-12-11

277

Poincare gauge theory from higher derivative matter lagrangean

Starting from matter lagrangean containing higher order derivative than the first, we construct the Poincare gauge theory by localising the Poincare symmetry of the matter theory. The construction is shown to follow the usual geometric procedure of gravitational coupling, thereby buttressing the geometric interpretation of the Poincare gauge theory.

Mukherjee, Pradip

2009-01-01

278

Improved Moving Puncture Gauge Conditions for Compact Binary Evolutions

Robust gauge conditions are critically important to the stability and accuracy of numerical relativity (NR) simulations involving compact objects. Most of the NR community use the highly robust---though decade-old---moving-puncture (MP) gauge conditions for such simulations. It has been argued that in binary black hole (BBH) evolutions adopting this gauge, noise generated near adaptive-mesh-refinement (AMR) boundaries does not converge away cleanly with increasing resolution, severely limiting gravitational waveform accuracy at computationally feasible resolutions. We link this noise to a sharp, initial outgoing gauge wave crossing into progressively lower resolution AMR grids, and present improvements to the standard MP gauge conditions that focus on stretching, smoothing, and more rapidly settling this outgoing wave. Our best gauge choice greatly reduces gravitational waveform noise, yielding more cleanly convergent waveforms and $\\sim 40%$ lower waveform phase and amplitude errors during inspiral at typica...

Etienne, Zachariah B; Paschalidis, Vasileios; Kelly, Bernard J; Shapiro, Stuart L

2014-01-01

279

Determination of covariant Schwinger terms in anomalous gauge theories

International Nuclear Information System (INIS)

A functional integral method is used to determine equal time commutators between the covariant currents and the covariant Gauss-law operators in theories which are affected by an anomaly. By using a differential geometrical setup we show how the derivation of consistent- and covariant Schwinger terms can be understood on an equal footing. We find a modified consistency condition for the covariant anomaly. As a by-product the Bardeen-Zumino functional, which relates consistent and covariant anomalies, can be interpreted as connection on a certain line bundle over all gauge potentials. Finally the commutator anomalies are calculated for the two- and four dimensional case. (Author) 13 refs

280

International Nuclear Information System (INIS)

We study the linear post-Newtonian approximation to general relativity known as gravitoelectromagnetism (GEM); in particular, we examine the similarities and differences between GEM and electrodynamics. Notwithstanding some significant differences between them, we find that a special nonstationary metric in GEM can be employed to show explicitly that it is possible to introduce gravitational induction within GEM in close analogy with Faraday's law of induction and Lenz's law in electrodynamics. Some of the physical implications of gravitational induction are briefly discussed

281

Observers at rest in a stationary spacetime flat at infinity can measure small amounts of rest-mass+internal energies+kinetic energies+pressure energy in a small volume of fluid attached to a local inertial frame. The sum of these small amounts is the total "matter energy" for those observers. The total mass-energy minus the matter energy is the binding gravitational energy. Misner, Thorne and Wheeler evaluated the gravitational energy of a spherically symmetric static spa...

Katz, Joseph

2005-01-01

282

Origin of Weyl Anomaly as Pair Production in Dirac Sea

Using Dirac sea picture for both left and right moving Weyl fermion (massless fermions) in $1+1$ dimensional world with a general relativity metric field we calculate the Weyl anomaly. That is to say we calculate the trace of the energy-momentum tensor $T_{\\mu}^{\\> \\mu}$ arising from the fermions. With the gauge choice ansatz $g_{\\mu \

Habara, Yoshinobu; Ninomiya, Masao

2015-01-01

283

On Certain Conceptual Anomalies in Einstein's Theory of Relativity

Directory of Open Access Journals (Sweden)

Full Text Available There are a number of conceptual anomalies occurring in the Standard exposition of Einstein's Theory of Relativity. These anomalies relate to issues in both mathematics and in physics and penetrate to the very heart of Einstein's theory. This paper reveals and amplifies a few such anomalies, including the fact that Einstein's field equations for the so-called static vacuum configuration, $R_{mu u} = 0$, violates his Principle of Equivalence, and is therefore erroneous. This has a direct bearing on the usual concept of conservation of energy for the gravitational field and the conventional formulation for localisation of energy using Einstein's pseudo-tensor. Misconceptions as to the relationship between Minkowski spacetime and Special Relativity are also discussed, along with their relationships to the pseudo-Riemannian metric manifold of Einstein's gravitational field, and their fundamental geometric structures pertaining to spherical symmetry.

Crothers S. J.

2008-01-01

284

Ambiguities in the gravitational correction of quantum electrodynamics running coupling

We verify that quadratic divergences stemming from gravitational corrections to QED which have been conjectured to lead to asymptotic freedom near Planck scale are arbitrary (regularization dependent) and compatible with zero. Moreover we explicitly show that such arbitrary term contributes to the beta function of QED in a gauge dependent way in the gravitational sector.

Felipe, J C C; Brito, L C T; Sampaio, Marcos; Nemes, M C

2012-01-01

285

Framing Anomaly in the Effective Theory of Fractional Quantum Hall Effect

We consider the geometric part of the effective action for Fractional Quantum Hall Effect (FQHE). It is shown that accounting for the framing anomaly of the quantum Chern-Simons theory is essential to the obtain correct gravitational linear response functions. In the lowest order in gradients the linear response generating functional includes Chern-Simons, Wen-Zee and gravitational Chern- Simons terms. The latter term has a contribution from the framing anomaly which fixes the value of thermal Hall conductivity and contributes to the Hall viscosity of the FQH states on a sphere. We also discuss the effects of the framing anomaly on linear responses for non-Abelian FQH states.

Gromov, Andrey; You, Yizhi; Abanov, Alexander G; Fradkin, Eduardo

2014-01-01

286

Genetics Home Reference: Peters anomaly

... PubMed Recent literature OMIM Genetic disorder catalog Conditions > Peters anomaly On this page: Description Genetic changes Inheritance ... names Glossary definitions Reviewed January 2014 What is Peters anomaly? Peters anomaly is characterized by eye problems ...

287

Adding gauge fields to Kaplan's fermions

Energy Technology Data Exchange (ETDEWEB)

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.)

Blum, T. (Dept. of Physics, Univ. of Arizona, Tucson, AZ (United States)); Kaerkkaeinen, L. (Dept. of Physics, Univ. of Arizona, Tucson, AZ (United States))

1994-04-01

288

Conformal anomaly actions for dilaton interactions

We discuss, in conformally invariant field theories such as QCD with massless fermions, a possible link between the perturbative signature of the conformal anomaly, in the form of anomaly poles of the 1-particle irreducible effective action, and its description in terms of Wess-Zumino actions with a dilaton. The two descriptions are expected to capture the UV and IR behaviour of the conformal anomaly, in terms of fundamental and effective degrees of freedom respectively, with the dilaton effective state appearing in a nonlinear realization. As in the chiral case, conformal anomalies seem to be related to the appearance of these effective interactions in the 1PI action in all the gauge-invariant sectors of the Standard Model. We show that, as a consequence of the underlying anomalous symmetry, the infinite hierarchy of recurrence relations involving self-interactions of the dilaton is entirely determined only by the first four of them. This relation can be generalized to any even space-time dimension.

Rose, Luigi Delle; Serino, Mirko

2014-01-01

289

Supersymmetric gauge theories from string theory

International Nuclear Information System (INIS)

This thesis presents various ways to construct four-dimensional quantum field theories from string theory. In a first part we study the generation of a supersymmetric Yang-Mills theory, coupled to an adjoint chiral superfield, from type IIB string theory on non-compact Calabi-Yau manifolds, with D-branes wrapping certain sub-cycles. Properties of the gauge theory are then mapped to the geometric structure of the Calabi-Yau space. Even if the Calabi-Yau geometry is too complicated to evaluate the geometric integrals explicitly, one can then always use matrix model perturbation theory to calculate the effective superpotential. The second part of this work covers the generation of four-dimensional super-symmetric gauge theories, carrying several important characteristic features of the standard model, from compactifications of eleven-dimensional supergravity on G2-manifolds. If the latter contain conical singularities, chiral fermions are present in the four-dimensional gauge theory, which potentially lead to anomalies. We show that, locally at each singularity, these anomalies are cancelled by the non-invariance of the classical action through a mechanism called 'anomaly inflow'. Unfortunately, no explicit metric of a compact G2-manifold is known. Here we construct families of metrics on compact weak G2-manifolds, which contain two conical singularities. Weak G2-manifolds have properties that are similar to the ones of proper G2-manifolds, and hence the explicit examples might be useful to better understand the generic situation. Finally, we reconsider the relation between eleven-dimensional supergravity and the E8 x E8-heterotic string. This is done by carefully studying the anomalies that appear if the supergravity theory is formulated on a ten-manifold times the interval. Again we find that the anomalies cancel locally at the boundaries of the interval through anomaly inflow, provided one suitably modifies the classical action. (author)

290

Introduction to gauge theories of electroweak interactions

International Nuclear Information System (INIS)

Intended as a lecture for physicists who are not familiar with the sophisticated theoretical models in particle physics. Starting with the standard gauge model of electromagnetic, weak and strong interactions the recent developments of a unified gauge theory of electroweak interactions are shown. Shortcomings in the unitarity problem of the V-A fermi theory of charged intermediate vector bosons. Presented are the spontaneous symmetry breaking in quantum mechanics, the abelian higgs model as an example of a spontaneously broken gauge field theory, the minimal gauge group of electroweak interactions, the fermion mass generation. Further on the anomalies in quantum field theory are discussed and the radiative corrections to the vector boson masses are considered. (H.B.)

291

Anomalies, characters and strings

International Nuclear Information System (INIS)

One-loop modular invariant heterotic and type II closed string theories are proved to be anomaly free, apart from terms proportional to TrF2-TrR2. It is shown why this conclusion holds with remarkable generality for any conceivable fermionic string theory, regardless even of conformal invariance. A detailed discussion is given of the modular properties of character valued partition functions, upon which the proof is based. The fact that TrF2-TrR2 terms remain in the fermionic contribution to the anomaly is shown to be a consequence of Quillen's holomorphic anomaly. (orig.)

292

The purpose of this lesson is to model for students gravitational waves and how they are created. Students will build a simple "Gravitational Wave Demonstrator" using inexpensive materials (plastic wrap, plastic cups, water, food coloring, and rubber bands, marbles). Students should have a basic understanding of waves and be familiar with Einstein's theory of general relativity. The activity can be done either as a teacher demonstration or student activity. This lesson is part of the Cosmic Times teachers guide and is intended to be used in conjunction with the 1993 Cosmic Times Poster.

293

This article reviews current efforts and plans for gravitational-wave detection, the gravitational-wave sources that might be detected, and the information that the detectors might extract from the observed waves. Special attention is paid to (i) the LIGO/VIRGO network of earth-based, kilometer-scale laser interferometers, which is now under construction and will operate in the high-frequency band ($1$ to $10^4$ Hz), and (ii) a proposed 5-million-kilometer-long Laser Interfe...

Sathyaprakash B. S.; Winkler Walter

2008-01-01

294

Nonlocal regularizations of gauge theories

International Nuclear Information System (INIS)

A procedure is given for generalizing local, gauge-invariant field theories to nonlocal ones which are finite, Poincare invariant, and perturbatively unitary. These theories are endowed with nonlocal gauge symmetries which ensure current conservation and decoupling in the same way that their local analogs do in the parent theories. An elegant way of viewing the resulting on-shell symmetry transformations is as ''quantum representations'' of the local gauge group in which the representation matrices become field-dependent, nonlocal operators. By varying the scale of nonlocality one can obtain gauge-invariant regularization schemes which are manifestly Poincare invariant, perturbatively unitary, and free of automatic subtractions. Since our method does not entail changing either the particle content or the dimension of spacetime, it may preserve global supersymmetry. As applications we work out the electron self-energy and vacuum polarization in QED at one loop. The latter gives the surprising result that no Landau ghost occurs with the regulator on and before renormalization. Another surprise is the absence of an axial-vector anomaly

295

Nonlocal regularizations of gauge theories

A procedure is given for generalizing local, gauge-invariant field theories to nonlocal ones which are finite, Poincaré invariant, and perturbatively unitary. These theories are endowed with nonlocal gauge symmetries which ensure current conservation and decoupling in the same way that their local analogs do in the parent theories. An elegant way of viewing the resulting on-shell symmetry transformations is as ``quantum representations'' of the local gauge group in which the representation matrices become field-dependent, nonlocal operators. By varying the scale of nonlocality one can obtain gauge-invariant regularization schemes which are manifestly Poincaré invariant, perturbatively unitary, and free of automatic subtractions. Since our method does not entail changing either the particle content or the dimension of spacetime, it may preserve global supersymmetry. As applications we work out the electron self-energy and vacuum polarization in QED at one loop. The latter gives the surprising result that no Landau ghost occurs with the regulator on and before renormalization. Another surprise is the absence of an axial-vector anomaly.

Evens, D.; Moffat, J. W.; Kleppe, G.; Woodard, R. P.

1991-01-01

296

On the axial anomalies in external tensor fields

International Nuclear Information System (INIS)

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

297

International Nuclear Information System (INIS)

The author summarizes the works presented at the meeting on skyrmions and anomalies. He divides the principal issues of this workshop into five categories: QCD effective lagrangians, chiral bags and the Cheshire cat principle, strangeness problem, phenomenology, mathematical structure

298

Pediatric hepatic vascular anomalies

International Nuclear Information System (INIS)

The typical vascular anomalies (tumors and vascular malformations) that involve the liver in infants and children are summarized. Many of these lesions are complex and require multiple imaging modalities, often including angiography, for precise diagnosis. (orig.)

299

Analysis of the radio-metric data from Pioneer 10 and 11 spacecrafts has indicated the presence of an unmodeled acceleration starting at 20 AU, which has become known as the Pioneer anomaly. The nature of this acceleration is uncertain. In this paper we give a description of the effect and review some relevant mechanisms proposed to explain the observed anomaly. We also discuss on some future projects to investigate this phenomenon.

de Diego, Jose A

2008-01-01

300

Complex lymphatic anomalies include several diagnoses with overlapping patterns of clinical symptoms, anatomic location, imaging features, hematologic alterations, and complications. Lymphatic malformations likely arise through anomalous embryogenesis of the lymphatic system. Analysis of clinical, imaging, histologic, and hematologic features is often needed to reach a diagnosis. Aspiration of fluid collections can readily define fluid as chylous or not. The presence of chyle indicates dysfunction at the mesenteric or retroperitoneal level or above the cisterna chyli due to reflux. The imaging patterns of generalized lymphatic anomaly (GLA) and Gorham-Stout disease have been segregated with distinctive bone lesions and peri-osseous features. More aggressive histology (spindled lymphatic endothelial cells), clinical progression, hemorrhage, or moderate hematologic changes should raise suspicion for kaposiform lymphangiomatosis. Biopsy may be needed for diagnosis, though avoidance of rib biopsy is advised to prevent iatrogenic chronic pleural effusion. Lymphangiography can visualize the anatomy and function of the lymphatic system and may identify dysfunction of the thoracic duct in central conducting lymphatic anomalies. Local control and symptom relief are targeted by resection, laser therapy, and sclerotherapy. Emerging data suggest a role for medical therapies for complications of complex lymphatic anomalies. Outcomes include recurrent effusion, infection, pain, fracture, mortality, and rarely, malignancy. Complex lymphatic anomalies present significant diagnostic and therapeutic challenges. Results from a phase 2 study of sirolimus in these and other conditions are expected in 2014. Improved characterization of natural history, predictors of poor outcomes, responses to therapy, and further clinical trials are needed for complex lymphatic anomalies. PMID:25241096

Trenor, Cameron C; Chaudry, Gulraiz

2014-08-01

301

Trace anomaly and massless scalar degrees of freedom in gravity

International Nuclear Information System (INIS)

The trace anomaly of quantum fields in electromagnetic or gravitational backgrounds implies the existence of massless scalar poles in physical amplitudes involving the stress-energy tensor. Considering first the axial anomaly and using QED as an example, we compute the full one-loop triangle amplitude of the fermionic stress tensor with two current vertices, ??J?J?>, and exhibit the scalar pole in this amplitude associated with the trace anomaly, in the limit of zero electron mass m?0. To emphasize the infrared aspect of the anomaly, we use a dispersive approach and show that this amplitude and the existence of the massless scalar pole is determined completely by its ultraviolet finite terms, together with the requirements of Poincare invariance of the vacuum, Bose symmetry under interchange of J? and J?, and vector current and stress-tensor conservation. We derive a sum rule for the appropriate positive spectral function corresponding to the discontinuity of the triangle amplitude, showing that it becomes proportional to ?(k2) and therefore contains a massless scalar intermediate state in the conformal limit of zero electron mass. The effective action corresponding to the trace of the triangle amplitude can be expressed in local form by the introduction of two scalar auxiliary fields which satisfy massless wave equations. These massless scalar degrees of freedom couple to classical sources, dom couple to classical sources, contribute to gravitational scattering processes, and can have long range gravitational effects.

302

Gauged flavour symmetry for the light generations

We study the phenomenology of a model where an SU(2)^3 flavour symmetry acting on the first two generation quarks is gauged and Yukawa couplings for the light generations are generated by a see-saw mechanism involving heavy fermions needed to cancel flavour-gauge anomalies. We find that, in constrast to the SU(3)^3 case studied in the literature, most of the constraints related to the third generation, like electroweak precision bounds or B physics observables, can be evaded...

D Agnolo, Raffaele Tito; Straub, David M.

2012-01-01

303

Physical anomaly on the lattice

International Nuclear Information System (INIS)

The authors study the axial anomaly of chiral non-invariant generalized Wilson's action and point out a possibility that physical anomaly which is responsible for ?0 ? 2? decay and ?-eta-eta' mass difference vanishes. The physical anomaly is different from the commonly defined anomaly which has correct magnitude. (Auth.)

304

Introduction to gauge theories

International Nuclear Information System (INIS)

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)

305

Non-minimal Gauge Mediation and Moduli Stabilization

In this paper we consider U(1)-gauged Polony'i model with two spurions coupled to a twisted closed string modulus. This offers a consistent setup for metastable SUSY breakdown which allows for moduli stabilization and naturally leads to gauge or hybrid gauge/gravitational mediation mechanism. Due to the presence of the second spurion one can arrange for a solution of the \\mu and B_\\mu problems in a version of modified Giudice-Masiero mechanism, which works both in the limit of pure gauge mediation and in the mixed regime of hybrid mediation.

Jelinski, T; Pawelczyk, J

2009-01-01

306

Lattice formulation of chiral gauge theories

International Nuclear Information System (INIS)

We present a method for formulating gauge theories of chiral fermions in lattice field theory. The method makes use of a Wilson mass to remove doublers. Gauge invariance is then restored by modifying the theory in two ways: The magnitude of the fermion determinant is replaced with the square root of the determinant for a fermion with vectorlike couplings to the gauge field; a double limit is taken, in which the lattice spacing associated with the fermion field is sent to zero before the lattice spacing associated with the gauge field. The method applies only to theories whose fermions are in an anomaly-free representation of the gauge group. We also present a related technique for computing matrix elements of operators involving fermion fields. Although the analyses of these methods are couched in weak-coupling perturbation theory, it is argued that the computational prescriptions are gauge invariant in the presence of a nonperturbative gauge-field configuration. copyright 1996 The American Physical Society

307

The cancellation of worldsheet anomalies in the D=10 Green--Schwarz heterotic string sigma--model

We determine the two--dimensional Weyl, Lorentz and $\\kappa$--anomalies in the $D=10$ Green--Schwarz heterotic string sigma--model, in an $SO(1,9)$-Lorentz covariant background gauge, and prove their cancellation.

Lechner, K.; Tonin, M.

1996-01-01

308

At first, we discuss parallels electric and magnetic fields solutions in a gravitational background. Then, considering eletromagnetic and gravitational waves symmetries we show a particular solution for stationary gravitational waves. Finally we consider gravitation as a gauge theory (effective gravitational theory), evaluate the propagators of the model, analyze the corresponding quantum excitations and verify (confirm) the tree-level unitarity at many places of the model.

Pinheiro, C; Dias, G S; Pinheiro, Carlos; Dias, Gilmar S.

2000-01-01

309

Light-induced gauge fields for ultracold atoms

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.

Goldman, N.; Juzeli?nas, G.; Öhberg, P.; Spielman, I. B.

2014-12-01

310

Implications of a new light gauge boson for neutrino physics

We study the impact of light gauge bosons on neutrino physics. We show that they can explain the NuTeV anomaly and also escape the constraints from neutrino experiments if they are very weakly coupled and have a mass of a few GeV. Lighter gauge bosons with stronger couplings could explain both the NuTeV anomaly and the positive anomalous magnetic moment of the muon. However, in the simple model we consider in this paper (say a purely vectorial extra U(1) current), they appear to be in conflict with the precise measurements of \

Boehm, Celine

2004-01-01

311

Gravitational waves (GWs) are a hot topic and promise to play a central role in astrophysics, cosmology, and theoretical physics. Technological developments have led us to the brink of their direct observation, which could become a reality in the coming years. The direct observation of GWs will open an entirely new field: GW astronomy. This is expected to bring a revolution in our knowledge of the universe by allowing the observation of previously unseen phenomena, such as the coalescence of compact objects (neutron stars and black holes), the fall of stars into supermassive black holes, stellar core collapses, big-bang relics, and the new and unexpected.With a wide range of contributions by leading scientists in the field, Gravitational Waves covers topics such as the basics of GWs, various advanced topics, GW detectors, astrophysics of GW sources, numerical applications, and several recent theoretical developments. The material is written at a level suitable for postgraduate students entering the field.

Ciufolini, I; Moschella, U; Fre, P

2001-01-01

312

Shadow Fields and Local Supersymmetric Gauges

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.

Baulieu, L; Sorella, S P; Baulieu, Laurent; Bossard, Guillaume; Sorella, Silvio Paolo

2006-01-01

313

The gravitational N-body problem, for $N>2$, is the oldest unsolved problem in mathematical physics. Some of the most ideal examples that can be found in nature are globular star clusters, with $N \\sim 10^6$. In this overview, I discuss six types of fundamental sources of unpredictability, each of which poses a different challenge to attempts to determine the long-term behavior of these systems, governed by a peculiar type of thermodynamics.

Hut, Piet

1997-01-01

314

We investigate the effect of quantum metric fluctuations on qubits that are gravitationally coupled to a background spacetime. In our first example, we study the propagation of a qubit in flat spacetime whose metric is subject to flat quantum fluctuations with a Gaussian spectrum. We find that these fluctuations cause two changes in the state of the qubit: they lead to a phase drift, as well as the expected exponential suppression (decoherence) of the off-diagonal terms in t...

Kok, Pieter; Yurtsever, Ulvi

2003-01-01

315

International Nuclear Information System (INIS)

Gauge transformations whose algebra closes only modulo field dependent terms (soft gauge algebras) are studied in detail. The results are explicitly applied to a supersymmetric gauge theory, to gravity and to conformal gravity, all seen as gauge theories over x-space; the obvious applications to supergravity are pointed out. A consistency requirement for the gauge transformations of those fields which appear in the algebra is seen to rule out ''local translations'' as independent gauge transformations. (orig.)

316

Gauge-invariant formulation of gauge theories

International Nuclear Information System (INIS)

A general method for constructing gauge-invariant variables in theories of the Yang-Mills-type is given. In a particular case this method gives rise to a new gauge-condition, which generalizes the Lorentz-condition. (author)

317

Classical antiparticles. Quantum supersymmetry anomaly and constituent model

International Nuclear Information System (INIS)

The two ways of constrained systems quantization are considered from the point of view of their self-consistency at the quantum level. With a transparent example of a particle in the external electromagnetic field it is demonstrated that the procedure of gauge fixing turns out rather dangerous and may lead to a quantum anomaly in the operator algebra. Additional classical symmetries as an essential element for tracing out this anomaly are discussed. The two cases of spinning and a spinless particles in the external electromagnetic field are discussed to illustrate the situation

318

Supersymmetry breaking from superstrings and the gauge hierarchy

International Nuclear Information System (INIS)

The gauge hierarchy problem is reviewed and a class of effective field theories obtained from superstrings is described. These are characterized by a classical symmetry, related to the space-time duality of string theory, that is responsible for the suppression of observable supersymmetry breaking effects. At the quantum level, the symmetry is broken by anomalies that provide the seed of observable supersymmetry breaking, and an acceptably large gauge hierarchy may be generated. 39 refs

319

Supersymmetry breaking from superstrings and the gauge hierarchy

International Nuclear Information System (INIS)

The gauge hierarchy problem is reviewed and a class of effective field theories obtained from superstrings is described. These are characterized by a classical symmetry, related to the space-time duality of string theory, that is responsible for the suppression of observable supersymmetry breaking effects. At the quantum level, the symmetry is broken by anomalies that provide the seed of observable supersymmetry breaking, and the acceptably large gauge hierarchy may be generated. 39 refs. (author)

320

Holographic Renormalisation and Anomalies

The Weyl anomaly in the Holographic Renormalisation Group as implemented using Hamilton-Jacobi language is studied in detail. We investigate the breakdown of the descent equations in order to isolate the Weyl anomaly of the dual field theory close to the (UV) fixed point. We use the freedom of adding finite terms to the renormalised effective action in order to bring the anomalies in the expected form. We comment on different ways of describing the bare and renormalised schemes, and on possible interpretations of the descent equations as describing the renormalisation group flow non-perturbatively. We find that under suitable assumptions these relations may lead to a class of c-functions.

Kalkkinen, J; Mück, W; Kalkkinen, Jussi; Martelli, Dario; Mueck, Wolfgang

2001-01-01

321

The ? transformation and gravitational copies

International Nuclear Information System (INIS)

An Abelian symmetry already considered by Einstein with respect to his asymmetrical field theories is related to the gravitational and gauge field copy phenomenon. It is shown that gauge field copies arise out of a straightforward generalization of the ? - map. The connection between Einstein's work on the ?-transformation and the copy phenomenon is obtained with the help of the Frobenius Theorem on the existence of foliations on a differentiable manifold. A problem like the one above is usually treated within the language of (intrinsic) Differential Geometry; General Relativity and classical unified field theories are traditionally developed in a classical style, that gap, a long introduction is prepared where the same structures are studied from the traditional and from the more recent point of view. (author)

322

Scalar-tensor theories, trace anomalies and the QCD-frame

We consider the quantum effects of matter fields in scalar-tensor theories and clarify the role of trace anomaly when switching between conformally related `frames'. We exploit the property that the couplings between the scalar and the gauge fields are not frame-invariant and define a `QCD-frame', where the scalar is not coupled to the gluons. This frame generalizes the `Jordan frame' in the case of non-metric theories and is particularly convenient for gravitational phenomenology. Test bodies have trajectories that are as close as possible to geodesics with respect to such a metric and equivalence principle violations are directly proportional to the scalar coupling parameters written in this frame. We show how RG flow and decoupling work in metric and non-metric theories. RG-running commutes with the operation of switching between frames at different scales. When only matter loops are considered, our analysis confirms that metricity is stable under radiative corrections and shows that approximate metricity ...

Nitti, Francesco

2012-01-01

323

Z'-gauge Bosons as Harbingers of Low Mass Strings

Massive Z'-gauge bosons act as excellent harbingers for string compactifications with a low string scale. In D-brane models they are associated to U(1) gauge symmetries that are either anomalous in four dimensions or exhibit a hidden higher dimensional anomaly. We discuss the possible signals of massive Z'-gauge bosons at hadron collider machines (Tevatron, LHC) in a minimal D-brane model consisting out of four stacks of D-branes. In this construction, there are two massive gauge bosons, which can be naturally associated with baryon number B and B-L (L being lepton number). Here baryon number is always anomalous in four dimensions, whereas the presence of a four-dimensional B-L anomaly depends on the U(1)-charges of the right handed neutrinos. In case B-L is anomaly free, a mass hierarchy between the two associated Z'-gauge bosons can be explained. In our phenomenological discussion about the possible discovery of massive Z'-gauge bosons, we take as a benchmark scenario the dijet plus W signal, recently obser...

Anchordoqui, Luis A; Goldberg, Haim; Huang, Xing; Lüst, Dieter; Taylor, Tomasz R

2012-01-01

324

Green-Schwarz anomaly cancellation, world sheet instantons and wormholes

International Nuclear Information System (INIS)

We consider the breaking of the global conservation of gauge field charges which are commonly thought to survive the spontaneous breakdown of gauge symmetry brought about by Kalb-Ramond fields. Depending on the dilaton field and also the size of the compactifying space, the global charge breaking may take place due to world sheet instantons. In going to 3+1 dimensions one could have a serious problem in order to produce the hierarchies between the quark and the charged lepton masses using the mass protecting charges with the Green-Schwartz anomaly cancellation. Various unnatural features of this type of models are discussed. (author)

325

Axial anomaly and index theorem for manifolds with boundary

International Nuclear Information System (INIS)

The use of the APS theorem for detecting the axial anomaly in manifolds with a boundary is discussed. The necessity of imposing non-local boundary conditions for the euclidean Dirac operator is explained and a physical interpretation is provided. The notion of a ''handed'' non-local boundary condition is introduced. The index for the Dirac operator for general gauge fields is found for a cylinder and for a disk. A similar analysis is also carried out for general separable gauge fields in four dimensions. (orig.)

326

International Nuclear Information System (INIS)

The author discusses how gravitational lens studies is becoming a major focus of extragalactic astronomy and cosmology. This review is organized into five parts: an overview of the observational situation, a look at the state of theoretical work on lenses, a detailed look at three recently discovered types of lensing phenomena (luminous arcs, radio rings, quasar-galaxy associations), a review of progress on two old problems in lens studies (deriving unique lens mass distribution models, measurements of differential time delays), and an attempt to look into the future of lens studies

327

Hidden QCD in Chiral Gauge Theories

DEFF Research Database (Denmark)

The 't Hooft and Corrigan-Ramond limits of massless one-flavor QCD consider the two Weyl fermions to be respectively in the fundamental representation or the two index antisymmetric representation of the gauge group. We introduce a limit in which one of the two Weyl fermions is in the fundamental representation and the other in the two index antisymmetric representation of a generic SU(N) gauge group. This theory is chiral and to avoid gauge anomalies a more complicated chiral theory is needed. This is the generalized Georgi-Glashow model with one vector like fermion. We show that there is an interesting phase in which the considered chiral gauge theory, for any N, Higgses via a bilinear condensate: The gauge interactions break spontaneously to ordinary massless one-flavor SU(3) QCD. The additional elementary fermionic matter is uncharged under this SU(3) gauge theory. It is also seen that when the number of colors reduce to three it is exactly this hidden QCD which is revealed.

Ryttov, Thomas; Sannino, Francesco

2005-01-01

328

Eleven dimensional supergravity in light cone gauge

Light-cone gauge manifestly supersymmetric formulation of eleven dimensional supergravity is developed. The formulation is given entirely in terms of light cone scalar superfield, allowing us to treat all component fields on an equal footing. All higher derivative on mass shell manifestly supersymmetric 4-point functions invariant with respect to linear supersymmetry transformations and corresponding (in gravitational bosonic sector) to terms constructed from four Riemann te...

Metsaev, R. R.

2004-01-01

329

Finite gauge field theory and quantum gravity

International Nuclear Information System (INIS)

A quantum field theory which is Poincare invariant, gauge invariant, finite and unitary to all orders of perturbation theory is applied to quantum chromodynamics. Quantum gravity is finite and unitary to all orders of perturbation theory. The Bekenstein-Hawking entropy formula for a black hole is investigated in a conical Rindler space approximation to a black hole event horizon. A renormalization of the gravitational coupling constant is performed leading to a finite Bekenstein-Hawking entropy at the horizon. (author)

330

Gauge models with spontaneously broken local supersymmetry

International Nuclear Information System (INIS)

An effective low-energy lagrangian for gauge theories based on local supersymmetry spontaneously broken at an intermediate energy between the weak interaction and the Planck scale is obtained. The derivation uses the general coupling of the Yang-Mills matter system to n = 1 supergravity. As illustrative examples of this framework we exhibit realistic models of supersymmetric QED and of the electroweak theory with supersymmetry breaking induced by purely gravitational effects. (orig.)

331

On global anomalies in type IIB string theory

We study global gravitational anomalies in type IIB string theory with nontrivial middle cohomology. This requires the study of the action of diffeomorphisms on this group. Several results and constructions, including some recent vanishing results via elliptic genera, make it possible to consider this problem. Along the way, we describe in detail the intersection pairing and the action of diffeomorphisms, and highlight the appearance of various structures, including the Roch...

Sati, Hisham

2011-01-01

332

Virasoro algebra anomalies and deformations

International Nuclear Information System (INIS)

The authors relate the anomalies of string theories to the mathematical obstructions of Dirac's canonical quantisation. The cohomological features of the deformation approach to the quantisation procedure determine the topological nature of such anomalies. (author)

333

Virasoro algebra anomalies and deformations

Energy Technology Data Exchange (ETDEWEB)

The authors relate the anomalies of string theories to the mathematical obstructions of Dirac's canonical quantisation. The cohomological features of the deformation approach to the quantisation procedure determine the topological nature of such anomalies.

Bakas, I.; Kakas, A.C.

1987-05-01

334

A flyby anomaly for Juno? Not from standard physics

An empirical formula recently appeared in the literature to explain the observed anomalies of about ? ? ? ? 1 - 10 mm s-1 in the geocentric range-rates ? ? of the Galileo, NEAR and Rosetta spacecraft at some of their past perigee passages along unbound, hyperbolic trajectories.It predicts an anomaly of the order of 6 mm s-1 for the recent flyby of Juno, occurred on 9 October 2013.Data analyses to confirm or disproof it are currently ongoing.We numerically calculate the impact on the geocentric Juno's range rate of some classical and general relativistic dynamical effects which are either unmodeled or mismodeled to a certain level in the software used to process the data.They are: (a) the first even zonal harmonic coefficient J2 of the multipolar expansion of the terrestrial gravitational potential causing orbital perturbations both at the (a?) Newtonian (J2) and at the (a?) first post-Newtonian level (J2c-2) (b) the post-Newtonian gravitoelectric (GE) Schwarschild-like component of the Earth's gravitational field (c) the post-Newtonian gravitomagnetic (GM) Lense-Thirring effect.The magnitudes of their mismodeled and nominal range-rate signatures are: (a?) ????J2 ? 1 ? m s-1 (a?) ???J2c-2 ? 0.015 ? m s-1 (b) ???GE ? 25 ? m s-1 (c) ???GM ? 0.05 ? m s-1. If a flyby anomaly as large as a few mm s-1 will be finally found also for Juno, it will not be due to any of these standard gravitational effects. It turns out that a Rindler-type radial extra-acceleration of the same magnitude as in the Pioneer anomaly would impact the Juno's range-rate at a ???Rin ? 1.5 ? m s-1 level. Regardless of the quest for the flyby anomaly, all such effects are undetectable.

Iorio, L.

2014-12-01

335

We investigate the effect of quantum metric fluctuations on qubits that are gravitationally coupled to a background spacetime. In our first example, we study the propagation of a qubit in flat spacetime whose metric is subject to flat quantum fluctuations with a Gaussian spectrum. We find that these fluctuations cause two changes in the state of the qubit: they lead to a phase drift, as well as the expected exponential suppression (decoherence) of the off-diagonal terms in the density matrix. Secondly, we calculate the decoherence of a qubit in a circular orbit around a Schwarzschild black hole. The no-hair theorems suggest a quantum state for the metric in which the black hole's mass fluctuates with a thermal spectrum at the Hawking temperature. Again, we find that the orbiting qubit undergoes decoherence and a phase drift that both depend on the temperature of the black hole. Thirdly, we study the interaction of coherent and squeezed gravitational waves with a qubit in uniform motion. Finally, we investigat...

Kok, P; Kok, Pieter; Yurtsever, Ulvi

2003-01-01

336

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

International Nuclear Information System (INIS)

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

337

Schwinger--DeWitt proper-time method for odd-dimensional gauge theory

International Nuclear Information System (INIS)

The Schwinger--DeWitt proper-time method (WKB expansion) is applied to calculate the anomaly in odd-dimensional gauge theories. The parity violating part of effective action for gauge theory in odd dimensions with massless fermion is calculated explicitly and efficiently by this method. It is shown to be precisely the local Chern--Simons term

338

Corrections to Schwarzschild solution in noncommutative gauge theory of gravity

International Nuclear Information System (INIS)

A deformed Schwarzschild solution in noncommutative gauge theory of gravitation is obtained. The gauge potentials (tetrad fields) are determined up to the second order in the noncommutativity parameters ???. A deformed real metric is defined and its components are obtained. The noncommutativity correction to the red shift test of general relativity is calculated and it is concluded that the correction is too small to have observable effects. Implications of such a deformed Schwarzschild metric are also mentioned

339

Scalar lattice gauge theories are models for scalar fields with local gauge symmetries. No fundamental gauge fields, or link variables in a lattice regularization, are introduced. The latter rather emerge as collective excitations composed from scalars. For suitable parameters scalar lattice gauge theories lead to confinement, with all continuum observables identical to usual lattice gauge theories. These models or their fermionic counterpart may be helpful for a realization...

Wetterich, C.

2012-01-01

340

Chiral anomalies and AdS/CMT in two dimensions

I clarify some recent confusion regarding the holographic description of finite-density systems in two dimensions. Notably, the chiral anomaly for symmetry currents in 2d conformal field theories (CFT) completely determines their correlators. The important exception is a CFT with a gauge theory to which we may couple an external current, as in the probe D3/D3 system or the putative dual to the charged BTZ black hole. These systems are analyzed with an eye for potential conde...

Jensen, Kristan

2010-01-01

341

The Chiral Magnetic Effect and Anomaly-Induced Transport

The Chiral Magnetic Effect (CME) is the phenomenon of electric charge separation along the external magnetic field that is induced by the chirality imbalance. The CME is a macroscopic quantum effect - it is a manifestation of the chiral anomaly creating a collective motion in Dirac sea. Because the chirality imbalance is related to the global topology of gauge fields, the CME current is topologically protected and hence non-dissipative even in the presence of strong interact...

Kharzeev, Dmitri E.

2013-01-01

342

N=8 supergravity and Kaluza-Klein axial anomalies

International Nuclear Information System (INIS)

By consideration of the ten-dimensional supersymmetric string theory which may underly unification of gravity with the other elementary particle forces it is argued that the light fermions must reflect the cancellation of Kaluza-Klein axial anomalies in ten dimensions. Using a gauge group SU(8), and assuming that both dimensional compactification and supersymmetry breaking occur at the Planck scale, we arrive at a set of fermions consistent with the observed light quarks and leptons including the replication of families. (orig.)

343

Yang-Mills origin of gravitational symmetries

By regarding gravity as the convolution of left and right Yang-Mills theories, we derive in linearised approximation the gravitational symmetries of general covariance, p-form gauge invariance, local Lorentz invariance and local supersymmetry from the flat space Yang-Mills symmetries of local gauge invariance and global super-Poincar\\'e. As a concrete example we focus on the new-minimal (12+12) off-shell version of simple four-dimensional supergravity obtained by tensoring the off-shell Yang-Mills multiplets (4 + 4, N_L = 1) and (3 + 0, N_R = 0).

Anastasiou, A; Duff, M J; Hughes, L J; Nagy, S

2014-01-01

344

We show that there is a class of finite groups, the so-called perfect groups, which cannot exhibit anomalies. This implies that all non-Abelian finite simple groups are anomaly-free. On the other hand, non-perfect groups generically suffer from anomalies. We present two different ways that allow one to understand these statements.

Chen, Mu-Chun; Ratz, Michael; Trautner, Andreas; Vaudrevange, Patrick K S

2015-01-01

345

Torsion, parity-odd response, and anomalies in topological states

We study the response of a class of topological systems to electromagnetic and gravitational sources, including torsion and curvature. By using the technology of anomaly polynomials, we derive the parity-odd response of a massive Dirac fermion in d =2 +1 and d =4 +1 , which provides a simple model for a topological insulator. We discuss the covariant anomalies of the corresponding edge states, from a Callan-Harvey anomaly inflow, as well as a Hamiltonian spectral flow point of view. We also discuss the applicability of our results to other systems such as Weyl semimetals. Finally, using dimensional reduction from d =4 +1 , we derive the effective action for a d =3 +1 time-reversal invariant topological insulator in the presence of torsion and curvature, and discuss its various physical consequences.

Parrikar, Onkar; Hughes, Taylor L.; Leigh, Robert G.

2014-11-01

346

Gauging gravity with SO(1,3) for spin-1/2 particles

We demonstrate, by analogy with electromagnetism, that the geometric content in the theory of gravity is an indirect consequence of the fact that the gauge group in question is the Lorentz group SO(1,3). We hence construct field equations for gravity and a spin-1/2 particle in a gravitational field based on gauge considerations. Furthermore, we derive the weak field and Schroedinger limits of the Dirac equation of the particle in the gravitational field, especially in Fermi ...

Saha, Arpan; Mukhopadhyay, Banibrata

2012-01-01

347

Octonionic Gauge Formulation for Dyonic Fields

Starting with the generalized field equation of dyons and gravito-dyons, we study the theory of octonion variables to the SU (2) non-Abelian gauge formalism. We demonstrate the resemblance of octonion covariant derivative with the gauge covariant derivative of generalized fields of dyons.Expressing the generalized four-potential, current and fields of gravito-dyons in terms of split octonion variables, the U (1) abelian and SU (2) non-Abelian gauge structure of dyons and gravito-dyons are described. It is emphasized that in general the generalized four-current is not conserved but only the Noetherian four-current is considered to be conserved one. The present formalism yields the theory of electric (gravitational) charge (mass) in the absence of magnetic(Heavisidean) charge (mass) on dyons (gravito-dyons) or vice versa.

Dangwal, S; Negi, O P S; Dangwal, Shalini

2006-01-01

348

The gravitational analogue of the Witten effect

International Nuclear Information System (INIS)

In the presence of massive fermions, and assuming a non-vanishing theta-parameter as the only source of CP-violation, the Witten effect [a shift in the electric charge of a magnetic monopole due to CP-non-conservation] is shown to follow from an anomalous chiral commutator. Next, given the gravitational contribution to the chiral anomaly, the corresponding anomalous commutator for Dirac fermion currents in a gravitational background is derived. From that, we infer the equivalence of a theta R-tilde R term in the Lagrangian to a shift in the mass parameter of the NUT metric, in proportion to theta. This is interpreted as the gravitational analogue of the Witten effect. Its relevance to certain Kaluza-Klein monopoles is briefly discussed. (author)

349

We investigate the effect of quantum metric fluctuations on qubits that are gravitationally coupled to a background spacetime. In our first example, we study the propagation of a qubit in flat spacetime whose metric is subject to flat quantum fluctuations with a Gaussian spectrum. We find that these fluctuations cause two changes in the state of the qubit: they lead to a phase drift, as well as the expected exponential suppression (decoherence) of the off-diagonal terms in the density matrix. Although in principle observable, the current state of technology prohibits the experimental demonstration of the phase drift. Second, we calculate the decoherence of a qubit in a circular orbit around a Schwarzschild black hole. The no-hair theorems suggest a quantum state for the metric in which the black hole’s mass fluctuates with a thermal spectrum at the Hawking temperature. Again, we find that the orbiting qubit undergoes decoherence and a phase drift that both depend on the temperature of the black hole. Third, we study the interaction of coherent and squeezed gravitational waves with a qubit in uniform motion. Finally, we investigate the decoherence of an accelerating qubit in Minkowski spacetime due to the Unruh effect. In this case decoherence is not due to fluctuations in the metric, but instead is caused by coupling (which we model with a standard Hamiltonian) between the qubit and the thermal cloud of Unruh particles bathing it. When the accelerating qubit is entangled with a stationary partner, the decoherence should induce a corresponding loss in teleportation fidelity.

Kok, Pieter; Yurtsever, Ulvi

2003-10-01

350

International Nuclear Information System (INIS)

We investigate the effect of quantum metric fluctuations on qubits that are gravitationally coupled to a background spacetime. In our first example, we study the propagation of a qubit in flat spacetime whose metric is subject to flat quantum fluctuations with a Gaussian spectrum. We find that these fluctuations cause two changes in the state of the qubit: they lead to a phase drift, as well as the expected exponential suppression (decoherence) of the off-diagonal terms in the density matrix. Although in principle observable, the current state of technology prohibits the experimental demonstration of the phase drift. Second, we calculate the decoherence of a qubit in a circular orbit around a Schwarzschild black hole. The no-hair theorems suggest a quantum state for the metric in which the black hole's mass fluctuates with a thermal spectrum at the Hawking temperature. Again, we find that the orbiting qubit undergoes decoherence and a phase drift that both depend on the temperature of the black hole. Third, we study the interaction of coherent and squeezed gravitational waves with a qubit in uniform motion. Finally, we investigate the decoherence of an accelerating qubit in Minkowski spacetime due to the Unruh effect. In this case decoherence is not due to fluctuations in the metric, but instead is caused by coupling (which we model with a standard Hamiltonian) between the qubit and the thermal cloud of Unruh particles bathing it. When the accelerating qubit is entang it. When the accelerating qubit is entangled with a stationary partner, the decoherence should induce a corresponding loss in teleportation fidelity

351

GAUGE INVARIANCE AND ANOMALOUS GAUGE BOSON COUPLINGS

Using the S--matrix pinch technique we obtain to one loop order, gauge independent $\\gamma W^-W^+$ and $Z W^-W^+$ vertices in the context of the standard model, with all incoming momenta off--shell. We show that the vertices so constructed satisfy simple QED--like Ward identities. These gauge invariant vertices give rise to expressions for the magnetic dipole and electric quadrupole form factors of the W gauge boson, which, unlike previous treatments, satisfy the crucial pro...

Papavassiliou, Joannis; Philippides, Kostas

1995-01-01

352

Anomalies, branes, and currents

International Nuclear Information System (INIS)

When a D-brane wraps around a cycle of a curved manifold, the twisting of its normal bundle can induce chiral asymmetry in its world-volume theory. We obtain the general form of the resulting anomalies for D-branes and their intersections. They are not cancelled among themselves, and the standard inflow mechanism does not apply at first sight because of their apparent lack of factorizability and the apparent vanishing of the corresponding inflow. We show, however, that after taking into consideration the effects of the non-trivial topology of the normal bundles, the anomalies can be transformed into factorized forms and precisely cancelled by finite inflow from the Chern-Simons actions for the D-branes as long as the latter are well defined. We then consider examples in type II compactifications where the twisting of the normal bundles occurs and calculate the changes in the induced Ramond-Ramond charges on the D-branes. (orig.)

353

Covariant Quiver Gauge Theories

We consider dimensional reduction of gauge theories with arbitrary gauge group in a formalism based on equivariant principal bundles. For the classical gauge groups we clarify the relations between equivariant principal bundles and quiver bundles, and show that the reduced quiver gauge theories are all generically built on the same universal symmetry breaking pattern. The formalism enables the dimensional reduction of Chern-Simons gauge theories in arbitrary odd dimensionalities. The reduced model is a novel Chern-Simons-Higgs theory consisting of a Chern-Simons term valued in the residual gauge group plus a higher order gauge and diffeomorphism invariant coupling of Higgs fields with the gauge fields. We study the moduli spaces of solutions, which in some instances provide geometric representations of certain quiver varieties as moduli spaces of flat invariant connections. As physical applications, we consider dimensional reductions involving non-compact gauge supergroups as a means for systematically induci...

Szabo, Richard J

2014-01-01

354

Masses by gauge flavor dynamics

We argue that gauging the experimentally observed flavor (family) SU(3)_F index of chiral charged lepton and quark fields results in microscopic model of the dynamical generation of masses of the Standard model particles. Suggested asymptotically free dynamics with an assumed non-perturbative infrared fixed point has just one free parameter and is therefore either right or plainly wrong. Weak point of field theories strongly coupled in the infrared, unfortunately, is that there is no reliable way of computing their spectrum. Because of its rigidity the model provides, however, rather firm theoretically safe experimental predictions without knowing the spectrum: First, anomaly freedom fixes the neutrino sector which contains almost sterile neutrino states. Second, global symmetries of the model, spontaneously broken by fermion masses imply the existence of a fixed pattern of (pseudo-)axions and (pseudo-)majorons. It is gratifying that the predicted both sterile neutrinos and the pseudo-Nambu--Goldstone bosons ...

Benes, Petr; Smetana, Adam

2011-01-01

355

South Atlantic anomaly campaign

Ever since the days of the first satellite observations of the fluxes of high-energy particles in the South Atlantic Anomaly, there has been interest in the possible atmospheric effects of the precipitating particles. Recently, Gledhill and Hoffman (J. Geophys. Res., 86, 6739-6744, 1981) have published electron fluxes observed near 300-km altitude by the AE-C satellite. From the observed fluxes it may be estimated that there should normally be extra ionization observable in the D and E regions, especially at night, and about 1 R of emission at 391.4 nm.Project ISAAC (International South Atlantic Anomaly Campaign) is designed to investigate these predictions. The research vessel SA Agulhas will pass through the region of greatest precipitating electron flux, as observed by Gledhill and Hoffman, carrying an ionosonde, a riometer, and photometers. Simultaneously, observations will be made by groups in countries around the South Atlantic—Argentina, Chile, Brazil, and South Africa—and by the Antarctic stations run by the United Kingdom, the United States, and South Africa. Some of these will focus on electromagnetic waves passing through the anomaly; others will focus on upper-atmospheric phenomena via the conventional methods—ionosondes, riometers, airglow photometers, etc.

Gledhill, A. J.

356

Penile anomalies in adolescence.

This article considers the impact and outcomes of both treatment and underlying condition of penile anomalies in adolescent males. Major congenital anomalies (such as exstrophy/epispadias) are discussed, including the psychological outcomes, common problems (such as corporal asymmetry, chordee, and scarring) in this group, and surgical assessment for potential surgical candidates. The emergence of new surgical techniques continues to improve outcomes and potentially raises patient expectations. The importance of balanced discussion in conditions such as micropenis, including multidisciplinary support for patients, is important in order to achieve appropriate treatment decisions. Topical treatments may be of value, but in extreme cases, phalloplasty is a valuable option for patients to consider. In buried penis, the importance of careful assessment and, for the majority, a delay in surgery until puberty has completed is emphasised. In hypospadias patients, the variety of surgical procedures has complicated assessment of outcomes. It appears that true surgical success may be difficult to measure as many men who have had earlier operations are not reassessed in either puberty or adult life. There is also a brief discussion of acquired penile anomalies, including causation and treatment of lymphoedema, penile fracture/trauma, and priapism. PMID:21399858

Wood, Dan; Woodhouse, Christopher

2011-01-01

357

Constraining an Expanding Locally Anisotropic metric from the Pioneer anomaly

It is discussed the possibility of a fine-tuneable contribution to the two way Doppler acceleration either towards, either outwards the Sun for heliocentric distances above 20 AU by considering a background described by an Expanding Locally Anisotropic (ELA) metric. This metric encodes both the standard local Schwarzschild gravitational effects and the cosmological Universe expansion effects allowing simultaneously to fine-tune other gravitational effects at intermediate scales, which may be tentatively interpreted as a covariant parameterization of either cold dark matter either gravitational interaction corrections. Are derived bounds for the ELA metric functional parameter by considering the bounds on the deviation from standard General Relativity imposed by the current updated limits for the Pioneer anomaly, taking in consideration both the natural outgassing and on-board radiation pressure, resulting in an average Doppler acceleration outwards the Sun of a_p = +0.4^{+2.1}_{-2.0} x 10^{-10} (m/s^2). It is...

Ferreira, P Castelo

2012-01-01

358

We present a new method of gauge fixing to standard lattice Landau gauge, Max Re Tr $\\sum_{\\mu,x}U_{\\mu,x}$, in which the link configuration is recursively smeared; these smeared links are then gauge fixed by standard extremization. The resulting gauge transformation is simultaneously applied to the original links. Following this preconditioning, the links are gauge fixed again as usual. This method is free of Gribov copies, and we find that for physical parameters ($\\beta \\geq 2$ in SU(2)), it generally results in the gauge fixed configuration with the globally maximal trace. This method is a general technique for finding a unique minimum to global optimization problems.

Hetrick, J E; Forcrand, Ph. de

1998-01-01

359

Strain gauge installation tool

A tool and a method for attaching a strain gauge to a test specimen by maaining alignment of, and applying pressure to, the strain gauge during the bonding of the gauge to the specimen. The tool comprises rigid and compliant pads attached to a spring-loaded clamp. The pads are shaped to conform to the specimen surface to which the gauge is to be bonded. The shape of the pads permits the tool to align itself to the specimen and to maintain alignment of the gauge to the specimen during the bond curing process. A simplified method of attaching a strain gauge is provided by use of the tool.

Conard, Lisa Marie (Swissvale, PA)

1998-01-01

360

Gravitational interactions of higher-spin fermions

We investigate the cubic interactions of a massless higher-spin fermion with gravity in flat space and present covariant 2 ? s ? s vertices, compatible with the gauge symmetries of the system, preserving parity. This explicit construction relies on the BRST deformation scheme that assumes locality and Poincaré invariance. Consistent nontrivial cubic deformations exclude minimal gravitational coupling and may appear only with a number of derivatives constrained in a given range. Derived i...

Henneaux, Marc; Lucena Gomez, Gustavo; Rahman, Rakibur

2014-01-01

361

Gauged Wess–Zumino–Witten actions for generalized Poincaré algebras

International Nuclear Information System (INIS)

If the Chern–Simons theory is the appropriate gauge theory for the gravitational interaction, then these theories must satisfy the correspondence principle, namely they must be related to General Relativity. In this Letter a five-dimensional Chern–Simons action invariant under the generalized Poincaré algebra B5 is constructed and then it is proved that the corresponding gauged Wess–Zumino–Witten term contains the Einstein–Hilbert action. In the same way, we show that a five-dimensional Chern–Simons action, invariant under the Maxwell algebra B4, induces a gauged Wess–Zumino–Witten term that coincides with the four-dimensional topological gravity.

362

Two-dimensional Poincare gauge gravity with matter

International Nuclear Information System (INIS)

Two-dimensional Poincare gauge gravity is known to be completely integrable in vacuum. Interaction with matter fields usually destroys the integrability. We give a coordinate- and gauge-invariant formulation of the matter-gravity dynamics for the general quadratic Poincare gauge model. The particular cases of massless spinor and scalar field sources are analyzed in detail. Exact general solutions for the chiral boson and fermion matter field configurations are constructed. These describe the gravitational field of a black hole type and are similar to the vacuum solutions discovered earlier. Nonchiral solutions are investigated with the help of numerical methods

363

Cosmic Microwave Background anisotropies from second order gravitational perturbations

This paper presents a complete analysis of the effects of second order gravitational perturbations on Cosmic Microwave Background anisotropies, taking explicitly into account scalar, vector and tensor modes. We also consider the second order perturbations of the metric itself obtaining them, for a universe dominated by a collision-less fluid, in the Poisson gauge, by transforming the known results in the synchronous gauge. We discuss the resulting second order anisotropies i...

Mollerach, Silvia; Matarrese, Sabino

1997-01-01

364

Renormalisation group, trace anomaly and Feynman-Hellmann theorem

We show that the logarithmic derivative of the gauge coupling on the hadronic mass and the cosmological constant term of a gauge theory are related to the gluon condensate of the hadron and the vacuum respectively. These relations are akin to Feynman-Hellmann relations whose derivation for the case at hand is complicated by the construction of the gauge theory Hamiltonian. We bypass this problem by using a renormalisation group equation for composite operators and the trace anomaly. The relations serve as possible definitions of the gluon condensates themselves which are plagued in direct approaches by power divergences. In turn these results might help to determine the contribution of the QCD phase transition to the cosmological constant and test speculative ideas.

Del Debbio, Luigi; Zwicky, Roman

2014-06-01

365

Renormalization group, trace anomaly and Feynman-Hellmann theorem

We show that the logarithmic derivative of the gauge coupling on the hadronic mass and the cosmological constant term of a gauge theory are related to the gluon condensate of the hadron and the vacuum respectively. These relations are akin to Feynman-Hellmann relations whose derivation for the case at hand are complicated by the construction of the gauge theory Hamiltonian. We bypass this problem by using a renormalisation group equation for composite operators and the trace anomaly. The relations serve as possible definitions of the gluon condensates themselves which are plagued in direct approaches by power divergences. In turn these results might help to determine the contribution of the QCD phase transition to the cosmological constant and test speculative ideas.

Del Debbio, Luigi

2013-01-01

366

Anomalies and tadpoles in open/closed string duality

Energy Technology Data Exchange (ETDEWEB)

We discuss the role played by the divergences appearing in the interaction between a fractional D3 brane dressed with an SU(N) gauge field and a stack of N fractional D3 branes on the orbifolds C{sup 2}/Z{sub 2} and C{sup 3}/(Z{sub 2} x Z{sub 2}). In particular we show that the logarithmic divergences in the closed string channel, interpreted as due to twisted massless tadpoles, are mapped, under open/closed string duality, in the logarithmic ones in the open string channel, due to the massless states circulating in the annulus diagram and corresponding to the one-loop divergences that one finds in the gauge theory living in the worldvolume of the brane. This result provides quantitative evidence of why the chiral and scale anomalies of the supersymmetric and non-conformal gauge theories supported by the worldvolume of the branes can be inferred from supergravity calculations.

Liccardo, Antonella; Marotta, Raffaele; Pezzella, Franco [Dipartimento di Scienze Fisiche, Univ. di Napoli ' Federico II' and INFN, Sezione di Napoli Complesso Univ. Monte S Angelo, ed G, Via Cintia, I-80126 Naples (Italy)

2004-05-21

367

Anomalies and Tadpoles in Open/Closed String Duality

We discuss the role played by the divergences appearing in the interaction between a fractional D3 brane dressed with an SU(N) gauge field and a stack of N fractional D3 branes on the orbifolds C^2/Z_2 and C^3/(Z_2 x Z_2). In particular we show that the logarithmic divergences in the closed string channel, interpreted as due to twisted massless tadpoles, are mapped, under open/closed string duality, in the logarithmic ones in the open string channel, due to the massless states circulating in the annulus diagram and corresponding to the one-loop divergences that one finds in the gauge theory living in the world volume of the brane. This result provides a quantitative evidence of why the chiral and scale anomalies of the supersymmetric and non conformal gauge theories supported by the world volume of the branes can be inferred from supergravity calculations.

Liccardo, A; Pezzella, F

2003-01-01

368

International Nuclear Information System (INIS)

Results of astronomical observations over the past few years have caused an active search for 'dark' matter and 'dark' energy. To know the nature of 'dark' energy, it is first necessary to know the nature of gravitation. However, even standard gravitational energy still remains a problem in the modern theory of gravitation. We have applied special optical methods to the solution of the problem of gravitational energy. In the process of research two new features of the propagation of light in gravitational fields are found. The dependency of the inertial mass of accelerated particles on the action of the gravitation is defined. The problem of localization of gravitational energy is solved also. (author)

369

International Nuclear Information System (INIS)

It is shown that a consistent gauging of the Poincare group is capable of including Einstein's general relativity. This statement holds for matter particles of arbitrary spin, provided the nontrivial part of the vierbein is taken as the fundamental gravitational field, thus giving rise to a known modification of the original theory. Since the gauge approach implies that gravitation is an ordinary field theory over flat space, the standard prescriptions for calculating the asymmetric momentum tensor of both matter and gravitation are available. Applying Belinfante's flat-space symmetrization procedure to the latter, we prove that the symmetrization of the asymmetric matter tensor just gives the dynamically defined symmetric matter tensor, whereas the symmetrization of the asymmetric gravitational momentum tensor leads to another version of the field equations that reveals a deep analogy to the equations of electrodynamics. Furthermore a method is developed that admits an unambiguous calculation of gauge-fixing conditions from a given gauge-breaking term. Besides the harmonic gauge, which can be reproduced by means of this method, new gauge-fixing conditions for local translations and local Lorentz transformations are obtained. These gauge-fixing techniques, as well as the symmetrization procedure, may equally be generalized to the case of nonvanishing torsion

370

Classical chiral kinetic theory and anomalies in even space-time dimensions

International Nuclear Information System (INIS)

We propose a classical action for the motion of massless Weyl fermions in a background gauge field in (2N + 1) + 1 space-time dimensions. We use this action to derive the collisionless Boltzmann equation for a gas of such particles, and show how classical versions of the gauge and abelian chiral anomalies arise from the Chern character of the non-abelian Berry connection that parallel transports the spin degree of freedom in momentum space. (paper)

371

Running couplings in quantum theory of gravity coupled with gauge fields

In this paper we study the coupled system of non-abelian gauge fields with higher-derivative gravity. Charge renormalization is investigated in this coupled system. It is found that the leading term in the gauge coupling beta function comes due to interaction of gauge fields with gravitons. This is shown to be a universal quantity in the sense that it doesn't depend on the gauge coupling and the gauge group, but may depend on the other couplings of the action (gravitational and matter). The coupled system is studied at one-loop. It is found that the leading term of gauge beta function is zero at one-loop in four dimensions. The effect of gauge fields on the running of gravitational couplings is investigated. The coupled system of gauge field with higher-derivative gravity is shown to satisfy unitarity when quantum corrections are taken in to account. Moreover, it is found that Newton constant goes to zero at short distances. In this renormalizable and unitary theory of gauge field coupled with higher-derivative gravity, the leading term of the gauge beta function, found to be universal for all gauge groups, is further studied in more detail by isolating it in the context of abelian gauge theories coupled with gravity in four dimensions. Using self-duality of abelian gauge theories in four dimensions, this term of the gauge beta function is shown to be zero to all loops. This is found to be independent of the gravity action, regularization scheme and gauge fixing condition. An explicit one-loop computation for arbitrary gravity action further demonstrates the vanishing of this term in the gauge beta function in four dimensions, independent of the regularization scheme and gauge fixing condition. Consequences of this are discussed.

Narain, Gaurav; Anishetty, Ramesh

2013-10-01

372

Chiral Lagrangians, anomalies, supersymmetry, and holomorphy

Energy Technology Data Exchange (ETDEWEB)

We investigate higher-dimensional analogues of the bc systems of 2D RCFT. When coupled to gauge fields and Beltrami differentials defining integrable holomorphic structures, the bc partition functions can be explicitly evaluated using anomalies and holomorphy. The resulting induced actions generalize the chiral algebras of 2D RCFT to 2n dimensions. Moreover, bc systems in four and six dimensions are closely related to supersymmetric matter. In particular, we show that d=4, N=2 hypermultiplets induce a theory of self-dual Yang-Mills fields coupled to self-dual gravity. In this way the bc systems fermionize both the algebraic sector of the WZW{sub 4} theory, as defined by Losev et al., and the classical open N{sub ws}=2 string. (orig.).

Losev, A. [Institute of Theoretical and Experimental Physics, Moscow (Russian Federation)]|[Yale Univ., New Haven, CT (United States). Dept. of Physics; Moore, G. [Yale Univ., New Haven, CT (United States). Dept. of Physics; Nekrasov, N. [Institute of Theoretical and Experimental Physics, Moscow (Russian Federation)]|[Princeton Univ., NJ (United States). Dept. of Physics; Shatashvili, S. [Yale Univ., New Haven, CT (United States). Dept. of Physics

1997-01-20

373

Resurgent Transseries and the Holomorphic Anomaly

The gauge theoretic large N expansion yields an asymptotic series which requires a nonperturbative completion in order to be well defined. Recently, within the context of random matrix models, it was shown how to build resurgent transseries solutions encoding the full nonperturbative information beyond the 't Hooft genus expansion. On the other hand, via large N duality, random matrix models may be holographically described by B-model closed topological strings in local Calabi-Yau geometries. This raises the question of constructing the corresponding holographically dual resurgent transseries, tantamount to nonperturbative topological string theory. This paper addresses this point by showing how to construct resurgent transseries solutions to the holomorphic anomaly equations. These solutions are built upon (generalized) multi-instanton sectors, where the instanton actions are holomorphic. The asymptotic expansions around the multi-instanton sectors have both holomorphic and anti-holomorphic dependence, may a...

Santamaría, Ricardo Couso; Schiappa, Ricardo; Vonk, Marcel

2013-01-01

374

A holomorphic anomaly in the elliptic genus

We consider a class of gauged linear sigma models (GLSMs) in two dimensions that flow to non-compact (2,2) superconformal field theories in the infra-red, a prototype of which is the SL(2,\\IR)/U(1) (cigar) coset. We compute the elliptic genus of the GLSMs as a path-integral on the torus using supersymmetric localization. We find that the result is a Jacobi-like form that is non-holomorphic in the modular parameter $\\tau$ of the torus, with mock modular behavior. This agrees with a previously-computed expression in the cigar coset. We show that the lack of holomorphicity of the elliptic genus arises from the contributions of a compact boson with momentum and winding around the torus. This boson has an axionic shift symmetry and plays the role of a compensator field that is needed to cancel the chiral anomaly in the rest of the theory.

Murthy, Sameer

2013-01-01

375

Boundary conditions for gauged supergravity

Energy Technology Data Exchange (ETDEWEB)

Anti-de Sitter space is the natural ground state of the O(N) gauged supergravity theories. If the excited states approach anti-de Sitter space sufficiently fast at infnity that one can define asymptotic anti-de Sitter Killing vectors, then the gravitational radiation obeys a reflective boundary condition and one can define asymptotic supercovariant constant spinor fields. If the boundary conditions are invariant under the supersymmetry transformations generated by these spinor fields, then all the zero rest-mass fields obey reflective boundary conditions which require that the 'magnetic' components of the Weyl tensor and the spin-onefield strength fall off faster than the 'electric' components. The pseudo-scalar fields fall off faster than the scalar fields. Infinity is sufficiently flat that one can define a global OSp(4/N) algebra.

Hawking, S.W. (Cambridge Univ. (UK). Dept. of Applied Mathematics and Theoretical Physics)

1983-06-30

376

On the covariant gauge {alpha} of the linearized gravity in de Sitter spacetime

Energy Technology Data Exchange (ETDEWEB)

In previous work, we studied the linearized gravity with covariant gauge {beta}= 2/3 and {alpha}= 5/3. It was found that the sum of the source and initial contributions reproduces the correct field configuration over the whole de Sitter spacetime. In this paper, we extend this work to generalizing the linearized gravitational field in an arbitrary value of the gauge parameter {alpha} but the gauge parameter {beta} remains the same.

Cheong, Lee Yen [Department of Fundamental and Applied Science Universiti Teknologi Petronas, Bandar Seri Iskandar, 31750 Tronoh, Perak (Malaysia)

2012-09-26

377

Gauge theories, black hole evaporation and cosmic censorship

International Nuclear Information System (INIS)

Recent work of Linde, which suggests that gauge theories modify the effective gravitational constant, are applied to the theory of black hole evaporation. Considerable modification of the late stages of evaporation are predicted. Contrary to expectations, the black hole never attains a sufficient temperature to enter the antigravity regime, which would represent a failure of cosmic censorship. (orig.)

378

On the localization of the gravitational energy

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Using a formalism introduced by Feynman, Deser, Grishchuk, Petrov and Popova, the pseudotensors, such as de.ned by Einstein, Tolman, Landau/Lifshitz and Møller, are expessed as gauge dependent tensors in a background space, as the gravitational energy-momentum tensor of Deser, Grishchuk, Petrov and [...] Popova. Using a result obtained by Virbhadra for the energy density in the Reissner-Nordström spacetime, it is shown that the action of these gauge transformations on the above tensorial expressions is the same as the action of the coordinate transformations on the equivalent pseudotensorial expressions, meaning that these tensors can be set to zero at a point by a suitable choice of gauge transformation.

N., Pinto Neto; P. I., Trajtenberg.

2000-03-01

379

Gravitating non-Abelian cosmic strings

In this paper we study regular cosmic string solutions of the non-Abelian Higgs model coupled with the Einstein gravity. In order to do that, we constructed a set of coupled differential ordinary equation. Because there is no closed solution for this set of equations, we solve it numerically. The solutions that we are interested in asymptote to a flat space-time with a planar angle deficit. This model under consideration present two bosonic sectors, besides the non-Abelian gauge one, coupled minimally with the gravitational fields. The two bosonic sectors may present a direct coupling, which plays an important role on the behavior of the matter and gauge fields and also on the behavior on the geometry of the spacetime. We explicitly analyze the behaviors of the energy density and planar angle deficit as function of the energy scale where the gauge symmetry is spontaneously broken and the coupling interaction between the bosonic sectors.

Santo, Antônio de Padua

2015-01-01

380

Anomalies in spaces of even and odd dimensions in the scheme of stochastic quantization

International Nuclear Information System (INIS)

Axial anomalies in spaces of even and odd dimensions are studied by the method of stochastic quantization with a generalized scheme of stochastic regularization. Although the stochastic regularization formally preserves the axial and gauge symmetries, the standard even-dimensional axial anomalies of Dirac fermions are correctly reproduced in the limit in which the regularization is lifted, while the anomalies of the chiral fermions are reproduced in covariant form. An analysis is also made of the general conditions for the existence and canceling of anomalies of massless fermions that violate parity in odd-dimensional spaces. The stochastic scheme works in odd-dimensional spaces when the parity-violating anomalies are absent. The P-anomalous part of the effect action of infinitely heavy fermions in odd-dimensional spaces is calculated explicitly

381

We gauge the central charge of the N=2 supersymmetry algebra in rigid superspace. The Fayet Sohnius hypermultiplet with gauged central charge coincides on-shell with N=2 supersymmetric electrodynamics. The gauge couplings of the vector-tensor multiplet turn out to be nonpolynomial.

Dragon, N.; Theis, U.

1997-01-01

382

International Nuclear Information System (INIS)

A method of the construction of the superfield normal gauge in the vicinity of a fixed point is given. In order to construct gauge-invariant theoretical quantities the question on the normal gauge application to the supergravity theory is discussed

383

Gauge fields are special in the sense that they are invariant under gauge transformations and they lead to problems when we try quantizing them straightforwardly. To circumvent this problem we need to specify a gauge condition to fix gauge.

Sales, J. H. O.

2003-01-01

384

DEFF Research Database (Denmark)

Timing anomalies make worst-case execution time analysis much harder, because the analysis will have to consider all local choices. It has been widely recognised that certain hardware features are timing anomalous, while others are not. However, defining formally what a timing anomaly is, has been difficult. We examine previous definitions of timing anomalies, and identify examples where they do not align with common observations. We then provide a definition for consistently slower hardware traces that can be used to define timing anomalies and aligns with common observations.

Cassez, Franck; Hansen, Rene Rydhof

2012-01-01

385

Automated anomaly detection processor

Robust exploitation of tracking and surveillance data will provide an early warning and cueing capability for military and civilian Law Enforcement Agency operations. This will improve dynamic tasking of limited resources and hence operational efficiency. The challenge is to rapidly identify threat activity within a huge background of noncombatant traffic. We discuss development of an Automated Anomaly Detection Processor (AADP) that exploits multi-INT, multi-sensor tracking and surveillance data to rapidly identify and characterize events and/or objects of military interest, without requiring operators to specify threat behaviors or templates. The AADP has successfully detected an anomaly in traffic patterns in Los Angeles, analyzed ship track data collected during a Fleet Battle Experiment to detect simulated mine laying behavior amongst maritime noncombatants, and is currently under development for surface vessel tracking within the Coast Guard's Vessel Traffic Service to support port security, ship inspection, and harbor traffic control missions, and to monitor medical surveillance databases for early alert of a bioterrorist attack. The AADP can also be integrated into combat simulations to enhance model fidelity of multi-sensor fusion effects in military operations.

Kraiman, James B.; Arouh, Scott L.; Webb, Michael L.

2002-07-01

386

Independent experiments show a large anomaly in measurements of lunar orbital evolution, with applications to cosmology and the speed of light. The Moon has long been known to be slowly drifting farther from Earth due to tidal forces. The Lunar Laser Ranging Experiment (LLRE) indicates the Moon's semimajor axis increasing at 3.82 ± .07 cm/yr, anomalously high. If the Moon were today gaining angular momentum at this rate, it would have coincided with Earth less than 2 Gyr ago. Study of tidal rhythmites indicates a rate of 2.9 ± 0.6 cm/yr. Historical eclipse observations independently measure a recession rate of 2.82 ± .08 cm/yr. Detailed numerical simulation of lunar orbital evolution predicts 2.91 cm/yr. LLRE differs from three independent experiments by over12 sigma. A cosmology where speed of light c is related to time t by GM=tc^3 has been suggested to predict the redshifts of Type Ia supernovae, and a 4.507034% proportion of baryonic matter. If c were changing in the amount predicted, lunar orbital distance would appear to increase by an additional 0.935 cm/yr. An anomaly in the lunar orbit may be precisely calculated, shedding light on puzzles of 'dark energy'. In Planck units this cosmology may be summarized as M=R=t.Lunar Recession Rate;

Riofrio, L.

2012-12-01

387

Einstein, Entropy and Anomalies

This paper strengthens and defends the pluralistic implications of Einstein's successful, quantitative predictions of Brownian motion for a philosophical dispute about the nature of scientific advance that began between two prominent philosophers of science in the second half of the twentieth century (Thomas Kuhn and Paul Feyerabend). Kuhn promoted a monistic phase-model of scientific advance, according to which a paradigm driven `normal science' gives rise to its own anomalies, which then lead to a crisis and eventually a scientific revolution. Feyerabend stressed the importance of pluralism for scientific progress. He rejected Kuhn's model arguing that it fails to recognize the role that alternative theories can play in identifying exactly which phenomena are anomalous in the first place. On Feyerabend's account, Einstein's predictions allow for a crucial experiment between two incommensurable theories, and are an example of an anomaly that could refute the reigning paradigm only after the development of a competitor. Using Kuhn's specification of a disciplinary matrix to illustrate the incommensurability between the two paradigms, we examine the different research strategies available in this peculiar case. On the basis of our reconstruction, we conclude by rebutting some critics of Feyerabend's argument.

Sirtes, Daniel; Oberheim, Eric

2006-11-01

388

Some Friedmann cosmological solutions in the scale covariant theory of gravitation

Directory of Open Access Journals (Sweden)

Full Text Available The scale covariant theory of gravity admits the possibility of a time varying gravitational constant but contains a gauge function for which there is no independent equation. The circumstances under which explicit forms for a gauge function may be derived within the context of Friedmann-Robertson-Walker cosmological models are investigated and several forms are derived.

Aroonkumar Beesham

1991-06-01

389

Unified gauge theory on noncommutative space-time

International Nuclear Information System (INIS)

A gauge theory describing simultaneously different interactions between internal SU(2) gauge and gravitational fields is formulated, choosing the group SU(2) x SO(4,1) as a local symmetry. Both internal and external (space-time) symmetries are considered. All the fields are described by gauge potentials. A solution of Schwarzschild-Reissner-Nordstroem-de-Sitter type is obtained first in the commutative space-time. We suppose then that the space-time is noncommutative. The corrections for tetrad fields and metric components are calculated up to the second order in the noncommutativity parameter. The solutions reduce to the deformed Reissner-Nordstroem or Schwarzschild ones when the cosmological constant and the electric charge of the gravitational source respectively vanish. (author)

390

Numerically generated black-hole spacetimes: Interaction with gravitational waves

International Nuclear Information System (INIS)

In this paper we present results from a new two-dimensional numerical relativity code used to study the interaction of gravitational waves with a black hole. The initial data correspond to a single black hole superimposed with time-symmetric gravitational waves (Brill waves). A gauge-invariant method is presented for extracting the gravitational waves from the numerically generated spacetime. We show that the interaction between the gravitational wave and the black hole excites the quasinormal modes of the black hole. An extensive comparison of these results is made to black-hole perturbation theory. For low-amplitude initial gravitational waves, we find excellent agreement between the theoretically predicted scrl=2 and scrl=4 wave forms and the wave forms generated by the code. Additionally, a code test is performed wherein the propagation of the wave on the black-hole background is compared to the evolution predicted by perturbation theory

391

Gauge fixing and residual symmetries in gauge/gravity theories with extra dimensions

International Nuclear Information System (INIS)

We study compactified pure gauge/gravitational theories with gauge-fixing terms and show that these theories possess quantum mechanical supersymmetriclike symmetries between unphysical degrees of freedom. These residual symmetries are global symmetries and generated by quantum mechanical N=2 supercharges. Also, we establish a new one-parameter family of gauge choices for higher-dimensional gravity and calculate as a check of its validity one graviton exchange amplitude in the lowest tree-level approximation. We confirm that the result is indeed ? independent and the cancellation of the ? dependence is ensured by the residual symmetries. We also give a simple interpretation of the van Dam-Veltman-Zakharov discontinuity, which arises in the lowest tree-level approximation, from the supersymmetric point of view.

392

On the gauge aspects of gravity

We give a short outline, in Sec.\\ 2, of the historical development of the gauge idea as applied to internal (U(1),\\, SU(2),\\dots) and external (R^4,\\,SO(1,3),\\dots) symmetries and stress the fundamental importance of the corresponding conserved currents. In Sec.\\ 3, experimental results with neutron interferometers in the gravitational field of the earth, as inter- preted by means of the equivalence principle, can be predicted by means of the Dirac equation in an accelerated and rotating reference frame. Using the Dirac equation in such a non-inertial frame, we describe how in a gauge- theoretical approach (see Table 1) the Einstein-Cartan theory, residing in a Riemann-Cartan spacetime encompassing torsion and curvature, arises as the simplest gravitational theory. This is set in contrast to the Einsteinian approach yielding general relativity in a Riemannian spacetime. In Secs.\\ 4 and 5 we consider the conserved energy-momentum current of matter and gauge the associated translation subgroup. The Einsteinian ...

Gronwald, F

1996-01-01

393

The trace anomaly and dynamical vacuum energy in cosmology

Energy Technology Data Exchange (ETDEWEB)

The trace anomaly of conformal matter implies the existence of massless scalar poles in physical amplitudes involving the stress-energy tensor. These poles may be described by a local effective action with massless scalar fields, which couple to classical sources, contribute to gravitational scattering processes, and can have long range gravitational effects at macroscopic scales. In an effective field theory approach, the effective action of the anomaly is an infrared relevant term that should be added to the Einstein-Hilbert action of classical General Relativity to take account of macroscopic quantum effects. The additional scalar degrees of freedom contained in this effective action may be understood as responsible for both the Casimir effect in flat spacetime and large quantum backreaction effects at the horizon scale of cosmological spacetimes. These effects of the trace anomaly imply that the cosmological vacuum energy is dynamical, and its value depends on macroscopic boundary conditions at the cosmological horizon scale, rather than sensitivity to the extreme ultraviolet Planck scale.

Mottola, Emil [Los Alamos National Laboratory

2010-01-01

394

Geometric gauge unification of the four fundamental interactions of elementary particles

International Nuclear Information System (INIS)

A high-dimensional unified field theory of all fundamental forces between elementary particles is formulated with emphasis on the gauge theoretic treatment of gravitation. Firstly, the de Sitter gauge theory of gravitation is incorporated into the Kaluza-Klein scheme. The global SO(4,1) symmetry requirement leads to a uniformly curved spacetime, whereas the localization of the symmetry results in a generally curved ten-dimensional geometry. Gravitation is then described by the gauge fields A/sub ?//sup a/ as well as the metric fields g/sub ? nu/. The dual description of the gravitational fields is essential in casting the gauge theory of gravitation into the Kaluza-Klein scheme. On the other hand, this formulation brings about the Yang term as a source to Einstein's field equation. A test particle placed in this gravitational geometry is found not to follow a geodesic path in spacetime. This dilemma may be resolved by requiring that the gravitational charge, an analogue of the electric charge, carried by the particle is always zero. In fact, with this requirement and a built-in constraint in the 10-dimensional geometry, the contribution from the Yang term vanishes identically. Thus, secondly, a unified treatment of all fundamental forces is developed by extending the Kaluza-Klein scheme to a (10 + n)-dimensional scheme. Upon localization of the de Sitter symmetry, the Lorentz group SO(3,1) has locally been preserved

395

System for closure of a physical anomaly

Systems for closure of a physical anomaly. Closure is accomplished by a closure body with an exterior surface. The exterior surface contacts the opening of the anomaly and closes the anomaly. The closure body has a primary shape for closing the anomaly and a secondary shape for being positioned in the physical anomaly. The closure body preferably comprises a shape memory polymer.

Bearinger, Jane P; Maitland, Duncan J; Schumann, Daniel L; Wilson, Thomas S

2014-11-11

396

Low energy limit of parity-violating amplitudes and anomaly cancellations in type-I superstring

International Nuclear Information System (INIS)

The low energy limit of parity-violating one-loop amplitudes with external six gauge bosons is studied in type-I superstring theory. The leading contributions come from the integration region near the boundaries of moduli space and give the same anomaly as in the effective particle field theory. (author). 21 refs

397

Anomaly-free version of SU(2)U(1)U(1)/sup '/

International Nuclear Information System (INIS)

The most general anomaly-free version of the SU(2) x U(1) x U(1)' local gauge-invariant model is presented here, for two different Higgs structures (the minimal ones), as an extension of the SU(2) x U(1) Glashow-Weinberg-Salam model

398

Gauge covariance in non-Abelian gauge theories

International Nuclear Information System (INIS)

Manifestly Lorentz- and gauge-covariant formulation of the canonical Yang-Mills field theory is presented. It is exhibited that a local gauge transformation forms an invariant gauge family to which relevant one-parameter gauges belong. Gauge symmetries prescribed by the theory are realized by combination of a non-Abelian global gauge transformation and an Abelian local gauge transformation. A renormalization scheme is developed in connection with problems inherent in the theory. (author)

399

Exploring the web of heterotic string theories using anomalies

International Nuclear Information System (INIS)

We investigate how anomalies can be used to infer relations among different descriptions of heterotic string theory. Starting from the observation that the construction mechanism of heterotic orbifold compactifications considered up to now prevents them from being resolved into fully smooth Calabi-Yau compactification manifolds, we use a new mechanism to obtain an orbifold which does not suffer from the aforementioned limitations. We explain in general how to resolve orbifolds into smooth Calabi-Yau using toric geometry and gauged linear sigma models. The latter allow for studying the theory in various other regions of the string moduli space as well, which unveils interesting intermediate geometries. By following anomalies through the different regimes, we can match the orbifold theories to their smooth Calabi-Yau counterparts. In the process, we investigate discrete R and non-R orbifold symmetries and propose a mechanism for studying their fate in other regions of the moduli space. Finally, we introduce a novel anomaly cancelation mechanism in gauged linear sigma models, which manifests itself in target space as a description of compactification geometries with torsion and Neveu-Schwarz five branes.

400

Exploring the web of heterotic string theories using anomalies

Energy Technology Data Exchange (ETDEWEB)

We investigate how anomalies can be used to infer relations among different descriptions of heterotic string theory. Starting from the observation that the construction mechanism of heterotic orbifold compactifications considered up to now prevents them from being resolved into fully smooth Calabi-Yau compactification manifolds, we use a new mechanism to obtain an orbifold which does not suffer from the aforementioned limitations. We explain in general how to resolve orbifolds into smooth Calabi-Yau using toric geometry and gauged linear sigma models. The latter allow for studying the theory in various other regions of the string moduli space as well, which unveils interesting intermediate geometries. By following anomalies through the different regimes, we can match the orbifold theories to their smooth Calabi-Yau counterparts. In the process, we investigate discrete R and non-R orbifold symmetries and propose a mechanism for studying their fate in other regions of the moduli space. Finally, we introduce a novel anomaly cancelation mechanism in gauged linear sigma models, which manifests itself in target space as a description of compactification geometries with torsion and Neveu-Schwarz five branes.

Ruehle, Fabian

2013-07-15

401

Framing anomaly in the effective theory of the fractional quantum Hall effect.

We consider the geometric part of the effective action for the fractional quantum Hall effect (FQHE). It is shown that accounting for the framing anomaly of the quantum Chern-Simons theory is essential to obtain the correct gravitational linear response functions. In the lowest order in gradients, the linear response generating functional includes Chern-Simons, Wen-Zee, and gravitational Chern-Simons terms. The latter term has a contribution from the framing anomaly which fixes the value of thermal Hall conductivity and contributes to the Hall viscosity of the FQH states on a sphere. We also discuss the effects of the framing anomaly on linear responses for non-Abelian FQH states. PMID:25615495

Gromov, Andrey; Cho, Gil Young; You, Yizhi; Abanov, Alexander G; Fradkin, Eduardo

2015-01-01

402

Framing Anomaly in the Effective Theory of the Fractional Quantum Hall Effect

We consider the geometric part of the effective action for the fractional quantum Hall effect (FQHE). It is shown that accounting for the framing anomaly of the quantum Chern-Simons theory is essential to obtain the correct gravitational linear response functions. In the lowest order in gradients, the linear response generating functional includes Chern-Simons, Wen-Zee, and gravitational Chern-Simons terms. The latter term has a contribution from the framing anomaly which fixes the value of thermal Hall conductivity and contributes to the Hall viscosity of the FQH states on a sphere. We also discuss the effects of the framing anomaly on linear responses for non-Abelian FQH states.

Gromov, Andrey; Cho, Gil Young; You, Yizhi; Abanov, Alexander G.; Fradkin, Eduardo

2015-01-01

403

Seismic data fusion anomaly detection

Detecting anomalies in non-stationary signals has valuable applications in many fields including medicine and meteorology. These include uses such as identifying possible heart conditions from an Electrocardiography (ECG) signals or predicting earthquakes via seismographic data. Over the many choices of anomaly detection algorithms, it is important to compare possible methods. In this paper, we examine and compare two approaches to anomaly detection and see how data fusion methods may improve performance. The first approach involves using an artificial neural network (ANN) to detect anomalies in a wavelet de-noised signal. The other method uses a perspective neural network (PNN) to analyze an arbitrary number of "perspectives" or transformations of the observed signal for anomalies. Possible perspectives may include wavelet de-noising, Fourier transform, peak-filtering, etc.. In order to evaluate these techniques via signal fusion metrics, we must apply signal preprocessing techniques such as de-noising methods to the original signal and then use a neural network to find anomalies in the generated signal. From this secondary result it is possible to use data fusion techniques that can be evaluated via existing data fusion metrics for single and multiple perspectives. The result will show which anomaly detection method, according to the metrics, is better suited overall for anomaly detection applications. The method used in this study could be applied to compare other signal processing algorithms.

Harrity, Kyle; Blasch, Erik; Alford, Mark; Ezekiel, Soundararajan; Ferris, David

2014-06-01

404

Modern test of chiral anomalies

International Nuclear Information System (INIS)

Chiral anomalies are calculated using an effective Lagrangian technique introduced for anomalies by Wess and Zumino and recently reformulated by Witten. Anomalous amplitudes for vector currents decaying into three pseudoscalars are tested by comparison with K/sub l4/ decay and eta ? ?+?-?. 12 references

405

Axial anomaly in nonrenormalizable theories

International Nuclear Information System (INIS)

The anomaly for the axial current in nonrenormalizable theories with electromagnetic coupling is considered. The spinor electrodynamics with Pauli term is examined in detail using the Feynman graph technique and the point-splitting method. The same finite value for the axial anomaly emerges. (author)

406

Abnormal presentation of Peters? anomaly

A case of Peters? Anomaly with iridocyelitis was examined The eye had all the features of Perters? Anomaly with signs of cbornic iridocyclitis. The combination of these findings has not been reported in literature to our know-ledge, making this case a unique one.

Mehta Mehul; Murthy G

1988-01-01

407

Anomaly mediation deformed by axion

International Nuclear Information System (INIS)

We show that in supersymmetric axion models the axion supermultiplet obtains a sizable F-term due to a non-supersymmetric dynamics and it generally gives the gaugino masses comparable to the anomaly mediation contribution. Thus the gaugino mass relation predicted by the anomaly mediation effect can be significantly modified in the presence of axion to solve the strong CP problem

408

On the gravitational scattering of gravitational waves

We discuss the scattering of weak gravitational waves from a slowly rotating gravitational source, having mass M and angular momentum J. We start considering the dynamics of a massless spin-2 field {{? }? ? } propagating in the weak gravitational field of the source, writing down the Fierz-Pauli in the presence of a slightly curved background. We adopt a semiclassical framework, where the gravitational background is described as a classical external field; meanwhile, the spin-2 field is treated quantum mechanically. In the weak-coupling limit, in which the typical wavelength of {{? }? ? } satisfies {{? }? }\\gg {{R}s} (where Rs is the Schwarzschild radius of the source), we obtain the cross-section for the scattering process in the Born approximation. We also discuss helicity asymmetry, showing its relationship with the spin-2 field coupling to the derivatives of the background metric. We finally consider the transition to the case of gravitational wave scattering, showing that—under reasonable assumptions—gravitational waves are expected to follow the same behavior. Our results partly agree with those presented through the years by various authors. The present analysis suggests that the scattering of weak gravitational waves in the field of a macroscopic gravitational source still represents an interesting open issue for further careful investigation.

Sorge, Francesco

2015-02-01

409

On the induced transverse gauge invariant mass term

International Nuclear Information System (INIS)

We derive a general expression for the gauge invariant mass (mG) for an Abelian gauge field, as induced by vacuum polarization, in 1+1 dimensions. From its relation to the chiral anomaly, we show that mG has to satisfy a certain dynamical quantization condition. This quantization can, on the other hand, be explicitly verified by using the exact general expression for the gauge invariant mass in terms of the fermion propagator. This result is applied to some explicit examples, exploring the possibility of having interesting physical situations where the value of mG departs from its canonical value of e2/? for a single massless Dirac fermion in 1+1 dimensions. We also study the possibility of generalizing the results to the (2+1)-dimensional case at finite temperature, showing that there are indeed situations where a finite and non-vanishing gauge invariant mass is induced. (author)

410

The first decade of the new millenium should see the first direct detections of gravitational waves. This will be a milestone for fundamental physics and it will open the new observational science of gravitational wave astronomy. But gravitational waves already play an important role in the modeling of astrophysical systems. I review here the present state of gravitational radiation theory in relativity and astrophysics, and I then look at the development of detector sensiti...

Kokkotas, Kostas D.

1999-01-01

411

When two gravitating bodies reside in a material medium, Newton's law of universal gravitation must be modified to account for the presence of the medium. A modified expression of Newton's law is known in the literature, but lacks a clear connection with existing gravitational theory. Newton's law in the presence of a homogeneous material medium…

Ridgely, Charles T.

2011-01-01

412

Detection of gravitational radiation

Energy Technology Data Exchange (ETDEWEB)

In this report the main contributions presented at the named symposium are collected. These concern astrophysical sources of gravitational radiation, ultracryogenic gravitational wave experiments, read out and data analysis of gravitational wave antennas, cryogenic aspects of large mass cooling to mK temperatures, and metallurgical and engineering aspects of large Cu structure manufacturing. (HSI).

Holten, J.W. van [ed.

1994-12-31

413

Relativity theory and gravitation

International Nuclear Information System (INIS)

The paper on relativity theory and gravitation is presented as a preface to the first of the articles submitted to the Journal on general relativity. Newtonian gravitation and and observation, relativity, and the sources of the gravitational field, are all discussed. (UK)

414

Detection of gravitational radiation

International Nuclear Information System (INIS)

In this report the main contributions presented at the named symposium are collected. These concern astrophysical sources of gravitational radiation, ultracryogenic gravitational wave experiments, read out and data analysis of gravitational wave antennas, cryogenic aspects of large mass cooling to mK temperatures, and metallurgical and engineering aspects of large Cu structure manufacturing. (HSI)

415

Resource Letter: Gravitational Lensing

This Resource Letter provides a guide to a selection of the literature on gravitational lensing and its applications. Journal articles, books, popular articles, and websites are cited for the following topics: foundations of gravitational lensing, foundations of cosmology, history of gravitational lensing, strong lensing, weak lensing, and microlensing.

Treu, T; Clowe, D

2012-01-01

416

The axial anomaly at finite temperature

International Nuclear Information System (INIS)

The axial anomaly and its constraints are examined at finite temperature. The axial anomaly is shown to be the same at T not= 0 and T = 0. When T =Tsub(conf) might follow from the anomaly constraint. (orig.)

417

A new gauge for supersymmetric abelian gauge theories

International Nuclear Information System (INIS)

A new gauge for supersymmetric abelian gauge theories is presented. It is shown that this new gauge allows us to obtain terms which usually come as radiative corrections to the supersymmetric abelian gauge theories when one uses the Wess-Zumino gauge. (Author)

418

Introduction to gauge theories

International Nuclear Information System (INIS)

These lecture notes contain the text of five lectures and a Supplement. The lectures were given at the JINR-CERN School of Physics, Tabor, Czechoslovakia, 5-18 June 1983. The subgect of the lecinvariancetures: gauge of electromagnetic and weak interactions, higgs and supersymmetric particles. The Supplement contains reprints (or excerpts) of some classical papers on gauge invariance by V. Fock, F. London, O. Klein and H. Weyl, in which the concept of gauge invariance was introduced and developed

419

Energy Technology Data Exchange (ETDEWEB)

The nonassociativity of the octonion algebra makes necessitates a bimodule representation, in which each element is represented by a left and a right multiplier. This representation can then be used to generate gauge transformations for the purpose of constructing a field theory symmetric under a gauged octonion algebra, the nonassociativity of which appears as a failure of the representation to close, and hence produces new interactions in the gauge field kinetic term of the symmetric Lagrangian. 5 refs., 1 tab.

Lassig, C.C.; Joshi, G.C.

1995-01-19

420

International Nuclear Information System (INIS)

We study the phase structure of SU(2) gauge theories at zero and high temperature, with and without scalar matter fields, in terms of the symmetric/broken realization of the remnant gauge symmetry which exists after fixing to Coulomb gauge. The symmetric realization is associated with a linearly rising color Coulomb potential (which we compute numerically), and is a necessary but not sufficient condition for confinement.

421

The introduction of fermionic degrees of freedom in non-Abelian gauge theories has the potential of substantially altering the gauge dynamics. This dissertation present the results of studies of SU(3) gauge theories with increasing fundamental quark content by means of lattice simulations. After an introduction to the effects of including dynamical quarks in lattice simulations, results on pioneering attempts of the inclusion of dynamical charm quarks in large scale lattice simulations are re...

Deuzeman, Albert

2011-01-01

422

Short distance properties of cascading gauge theories

We study the short distance (large momentum) properties of correlation functions of cascading gauge theories by performing a tree-level computation in their dual gravitational background. We prove that these theories are holographically renormalizable; the correlators have only analytic ultraviolet divergences, which may be removed by appropriate local counterterms. We find that n-point correlation functions of properly normalized operators have the expected scaling in the semi-classical gravity (large N) limit: they scale as N_{eff}^{2-n} with N_{eff} proportional to ln(k/Lambda) where k is a typical momentum. Our analysis thus confirms the interpretation of the cascading gauge theories as renormalizable four-dimensional quantum field theories with an effective number of degrees of freedom which logarithmically increases with the energy.

Aharony, O; Yarom, A; Aharony, Ofer; Buchel, Alex; Yarom, Amos

2006-01-01

423

The Schwinger Model on S 1: Hamiltonian Formulation, Vacuum and Anomaly

We present a Hamiltonian formulation of the Schwinger model with spatial domain taken to be the circle. It is shown that, in Coulomb gauge, the Hamiltonian is a semi-bounded, self-adjoint operator which is invariant under the group of large gauge transformations. There is a nontrivial action of on fermionic Fock space and its vacuum. This action plays a role analogous to that played by the spectral flow in the infinite Dirac sea formalism. The formulation allows (1) a description of the anomaly and its relation to the group action, and (2) an explicit identification of the vacuum. The anomaly in the chiral conservation law appears as a consequence of insisting upon semi-boundedness and gauge invariance of the quantized Hamiltonian.

Stuart, David

2014-12-01

424

Fermion on Curved Spaces, Symmetries, and Quantum Anomalies

Directory of Open Access Journals (Sweden)

Full Text Available We review the geodesic motion of pseudo-classical spinning particles in curved spaces. Investigating the generalized Killing equations for spinning spaces, we express the constants of motion in terms of Killing-Yano tensors. Passing from the spinning spaces to the Dirac equation in curved backgrounds we point out the role of the Killing-Yano tensors in the construction of the Dirac-type operators. The general results are applied to the case of the four-dimensional Euclidean Taub-Newman-Unti-Tamburino space. The gravitational and axial anomalies are studied for generalized Euclidean Taub-NUT metrics which admit hidden symmetries analogous to the Runge-Lenz vector of the Kepler-type problem. Using the Atiyah-Patodi-Singer index theorem for manifolds with boundaries, it is shown that the these metrics make no contribution to the axial anomaly.

Mihai Visinescu

2006-11-01

425

Less Mundane Explanation of Pioneer Anomaly from Q-Relativity

Directory of Open Access Journals (Sweden)

Full Text Available There have been various explanations of Pioneer blueshift anomaly in the past few years; nonetheless no explanation has been off ered from the viewpoint of Q-relativity physics. In the present paper it is argued that Pioneer anomalous blueshift may be caused by Pioneer spacecraft experiencing angular shift induced by similar Q-elativity effect which may also affect Jupiter satellites. By taking into consideration "aether drift" effect, the proposed method as described herein could explain Pioneer blueshift anomaly within ~0.26% error range, which speaks for itself. Another new proposition of redshift quantization is also proposed from gravitational Bohr-radius which is consistent with Bohr-Sommerfeld quantization. Further observation is of course recommended in order to refute or verify this proposition.

Christianto V.

2007-01-01

426

Scalar potential and dyonic strings in 6D gauged supergravity

International Nuclear Information System (INIS)

In this paper we first give a simple parametrization of the scalar coset manifold of the only known anomaly free chiral gauged supergravity in six dimensions in the absence of linear multiplets, namely gauged minimal supergravity coupled to a tensor multiplet, E6 x E7 X U(1)R Yang-Mills multiplets and suitable number of hypermultiplets. We then construct the potential for the scalars and show that it has a unique minimum at the origin. We also construct a new BPS dyonic string solution in which U(1)R x U(1) gauge fields, in addition to the metric, dilaton and the 2-form potential, assume nontrivial configurations in any U(1)R gauged 6D minimal supergravity coupled to a tensor multiplet with gauge symmetry G contains U(1). The solution Preserves 1/4 of the 6D supersymmetries and can be trivially embedded in the anomaly free model, in which case the U(1) activated in our solution resides in E7. (author)

427

Implementing general gauge mediation

International Nuclear Information System (INIS)

Recently there has been much progress in building models of gauge mediation, often with predictions different than those of minimal gauge mediation. Meade, Seiberg, and Shih have characterized the most general spectrum which can arise in gauge-mediated models. We discuss some of the challenges of building models of general gauge mediation, especially the problem of messenger parity and issues connected with R symmetry breaking and CP violation. We build a variety of viable, weakly coupled models which exhibit some or all of the possible low energy parameters.

428

Are gauge symmetries symmetries

International Nuclear Information System (INIS)

In topologically non-trivial gauge theories there is in general an obstruction for implementing gauge transformations on the fields, and even those which can be implemented may fail to be symmetries. For instantons no non-trivial gauge transformation can be implemented. For a monopole the residual symmetry group G is implementable if the projection onto the centre of its non-Abelian charge Q is quantized. G is however a symmetry group only if Q belongs actually to the centre. In the non-Abelian Bohm-Aharonov experiment all gauge transformations are implementable but they are symmetries only if the enclosed flux is quantized

429

International Nuclear Information System (INIS)

The choice of time function for cosmological solutions of gravitational field equations is related to the action of the group of independent scale transformations of the unit of length along orthogonal spatial directions. This is accomplished by the introduction of lapse functions which depend explicitly on the spatial metric in an appropriately defined power-law fashion. The resulting power-law-lapse time gauges are the key to producing nearly all exact solutions of the class of models for which the field equations reduce to ordinary differential equations

430

A little more gauge mediation and the light Higgs mass

Energy Technology Data Exchange (ETDEWEB)

We consider minimal models of gauge mediated supersymmetry breaking with an extra U(1) factor in addition to the Standard Model gauge group. A U(1) charged, Standard Model singlet is assumed to be present which allows for an additional NMSSM like coupling, ?H{sub u}H{sub d}S. The U(1) is assumed to be flavour universal. Anomaly cancellation in the MSSM sector requires additional coloured degrees of freedom. The S field can get a large vacuum expectation value along with consistent electroweak symmetry breaking. It is shown that the lightest CP even Higgs boson can attain mass of the order of 125 GeV.

Suryanarayana Mummidi, V., E-mail: soori9@cts.iisc.ernet.in; Vempati, Sudhir K., E-mail: vempati@cts.iisc.ernet.in

2014-04-15

431

Supersymmetry breaking by type II seesaw assisted anomaly mediation

International Nuclear Information System (INIS)

Anomaly mediated supersymmetry breaking, when implemented in the minimal supersymmetric standard model, is known to suffer from the problem of negative slepton mass squared leading to the breakdown of electric charge conservation. We show, however, that when the minimal supersymmetric standard model is extended to explain small neutrino masses by including a pair of superheavy Higgs triplet superfields (the type II seesaw mechanism), the slepton masses can be deflected from the pure anomaly mediated supersymmetry breaking trajectory and become positive. In the simple model we present in this paper, the seesaw scale is about 1013-1014 GeV. Gauge coupling unification can be maintained by embedding the triplet to SU(5) 15-multiplet. In this scenario, the b-ino is the lightest supersymmetric particle and its mass is nearly degenerate with the next-to-lightest supersymmetric particle slepton when the triplet mass is right around the seesaw scale

432

Quantum gravitation. The Feynman path integral approach

Energy Technology Data Exchange (ETDEWEB)

The book covers the theory of Quantum Gravitation from the point of view of Feynman path integrals. These provide a manifestly covariant approach in which fundamental quantum aspects of the theory such as radiative corrections and the renormalization group can be systematically and consistently addressed. The path integral method is suitable for both perturbative as well as non-perturbative studies, and is known to already provide a framework of choice for the theoretical investigation of non-abelian gauge theories, the basis for three of the four known fundamental forces in nature. The book thus provides a coherent outline of the present status of the theory gravity based on Feynman's formulation, with an emphasis on quantitative results. Topics are organized in such a way that the correspondence to similar methods and results in modern gauge theories becomes apparent. Covariant perturbation theory are developed using the full machinery of Feynman rules, gauge fixing, background methods and ghosts. The renormalization group for gravity and the existence of non-trivial ultraviolet fixed points are investigated, stressing a close correspondence with well understood statistical field theory models. Later the lattice formulation of gravity is presented as an essential tool towards an understanding of key features of the non-perturbative vacuum. The book ends with a discussion of contemporary issues in quantum cosmology such as scale dependent gravitational constants and quantum effects in the early universe. (orig.)

Hamber, Herbert W. [California Univ., Irvine, CA (United States). Dept. of Physics and Astronomy

2009-07-01

433

Anomaly in photoelectron angular distributions

International Nuclear Information System (INIS)

The recently observed anomaly in photoelectron angular distributions (PADs), the disappearance of the main lobes of PADs which should be usually in the direction of laser polarization, is reinterpreted as a minimum of generalized Bessel functions in the laser-polarization direction with the theory of nonperturbative quantum electrodynamics. The reinterpretation has no artificial fitting parameters and explains more features of the experimentally observed PADs, in contrast to the existing interpretation in which the anomaly is interpreted as a quantum interference of angular momentum partial waves. Some hierarchy anomalies are predicted for further experimental observations

434

Theory of Classical Higgs Fields. III. Metric-affine gauge theory

We consider classical gauge theory with spontaneous symmetry breaking on a principal bundle $P\\to X$ whose structure group $G$ is reducible to a closed subgroup $H$, and sections of the quotient bundle $P/H\\to X$ are treated as classical Higgs fields. Its most comprehensive example is metric-affine gauge theory on the category of natural bundles where gauge fields are general linear connections on a manifold $X$, classical Higgs fields are arbitrary pseudo-Riemannian metrics on $X$, and matter fields are spinor fields. In particular, this is the case of gauge gravitation theory.

Sardanashvily, G

2015-01-01

435

Gauge invariant correlators in noncommutative gauge theory

International Nuclear Information System (INIS)

Using perturbation theory, we explore the universal high momentum behavior of correlation functions of gauge invariant operators in planar noncommutative gauge theories. We find that the correlation functions are strongly enhanced when pairs of momenta become antiparallel. In particular, there is a transition from the previously noted exponential suppression of correlation functions at high momenta to a more field theoretic behavior when the momenta of pairs of operators antialign within a critical angle. Some of our calculations can be extrapolated to strong coupling, and in particular we are able to reproduce precisely the supergravity prediction for the behavior of two point functions, including the coupling dependence

436

Chiral anomalies and AdS/CMT in two dimensions

I clarify some recent confusion regarding the holographic description of finite-density systems in two dimensions. Notably, the chiral anomaly for symmetry currents in 2d conformal field theories (CFT) completely determines their correlators. The important exception is a CFT with a gauge theory to which we may couple an external current, as in the probe D3/D3 system or the putative dual to the charged BTZ black hole. These systems are analyzed with an eye for potential condensed matter applications.

Jensen, Kristan

2010-01-01

437

An $O(3)$ Global Anomaly in 0+1 Dimension

We present a simple exactly solvable quantum mechanical example of the global anomaly in an $O(3)$ model with an odd number of fermionic triplets coupled to a gauge field on a circle. Because the fundamental group is non-trivial, $\\pi_1 (O(3)) ={\\bf Z}_2$, fermionic level crossing or circling occur in the eigenvalue spectrum of the 1-dim. Dirac \\op under continuous external field transformations. They are shown to be related to the presence of an odd number of normalizable z...

Axenides, Minos; Johansen, Andrei; Nielsen, Holger Bech

1993-01-01

438

Energy Technology Data Exchange (ETDEWEB)

We examine the supersymmetry Ward identity for supersymmetric Yang-Mills theories in the axial gauge. In the pure N=1 (no matter) case the Ward identity leads to supersymmetric counterterms to all orders. This result does not survive the introduction of matter fields, however, and we therefore conclude that the gauge is not useful in the context of supersymmetry. (orig.).

Capper, D.M.; Packman, M.N.; Jones, D.R.T.

1986-01-13

439

Obstetric consequences of uterovaginal anomalies

Energy Technology Data Exchange (ETDEWEB)

This review discusses the diagnosis and classification of utero-vaginal anomalies as well as obstetric considerations in their management. Diagnosis is usually made by hysterosalpingography antepartum. Ultrasonography is also recommended. 40 references, 10 figures, 9 tables.

Rock, J.A.; Schlaff, W.D.

1985-05-01

440

Can Schwarzschildean gravitational fields suppress gravitational waves?

Gravitational waves in the linear approximation propagate in the Schwarzschild spacetime similarly as electromagnetic waves. A fraction of the radiation scatters off the curvature of the geometry. The energy of the backscattered part of an initially outgoing pulse of the quadrupole gravitational radiation is estimated by compact formulas depending on the initial energy, the Schwarzschild radius, and the location and width of the pulse. The backscatter becomes negligible in t...

Malec, Edward; Schaefer, Gerhard

2001-01-01

441

Situs anomalies on prenatal MRI

International Nuclear Information System (INIS)

Objective: Situs anomalies refer to an abnormal organ arrangement, which may be associated with severe errors of development. Due regard being given to prenatal magnetic resonance imaging (MRI) as an adjunct to ultrasonography (US), this study sought to demonstrate the in utero visualization of situs anomalies on MRI, compared to US. Materials and methods: This retrospective study included 12 fetuses with situs anomalies depicted on fetal MRI using prenatal US as a comparison modality. With an MRI standard protocol, the whole fetus was assessed for anomalies, with regard to the position and morphology of the following structures: heart; venous drainage and aorta; stomach and intestines; liver and gallbladder; and the presence and number of spleens. Results: Situs inversus totalis was found in 3/12 fetuses; situs inversus with levocardia in 1/12 fetuses; situs inversus abdominis in 2/12 fetuses; situs ambiguous with polysplenia in 3/12 fetuses, and with asplenia in 2/12 fetuses; and isolated dextrocardia in 1/12 fetuses. Congenital heart defects (CHDs), vascular anomalies, and intestinal malrotations were the most frequent associated malformations. In 5/12 cases, the US and MRI diagnoses were concordant. Compared to US, in 7/12 cases, additional MRI findings specified the situs anomaly, but CHDs were only partially visualized in six cases. Conclusions: Our initial MRI results demonstrate the visualization of situs anomalies and associated malformations in utero, which associated malformations in utero, which may provide important information for perinatal management. Using a standard protocol, MRI may identify additional findings, compared to US, which confirm and specify the situs anomaly, but, with limited MRI visualization of fetal CHDs.

442

Axial Anomaly and Transition Formfactors

We study photon-meson transition formfactors of light mesons in the kinematics, where one photon is real and other is virtual. Dispersive approach to axial anomaly leads to the anomaly sum rule. The absence of corrections to it allows us to get the relation between possible corrections to continuum and to lower states within QCD method which does not rely on factorization hypothesis. We show, relying on the recent data of the BaBar Collaboration, that the relative correction...

Bando, Masako; Harada, Masayasu

2010-01-01

443

Quaternion gauge fields. Pseudocolor

International Nuclear Information System (INIS)

A simplified Guenaydin-Guersey model, in which a Majorana field constructed using quaternions combines a lepton and a color quark, is considered. Formulation of the gauge principle directly in the quaternions leads to the appearance of two vector quaternion gauge fields, these corresponding to the decomposition SO(4) ? SO(3) x SO(3) of the invariance group. The diagonal subgroup SO(3) of automorphisms of the quarternions appears as a pseudocolor symmetry of the quarks, and the gauge field corresponding to it as the field of three color gluons. The other gauge field corresponds to lepton-quark transitions and in the presence of spontaneous breaking of the SO(4) gauge symmetry by the scalar quaternion field acquires a (large) finite mass

444

Quaternion gauge field. Pseudocolor

International Nuclear Information System (INIS)

A simplified Guersay-Guenaydin model in which a lepton and a colour quark are united in the Majorana quaternion field is considered. Direct formulation of the gauge principle in the framework of quaternions leads to the appearance of two vector gauge quaternion fields corresponding to the decomposition of the invariance group SO(4)?SO(3)xSO(3). The diagonal subgroup SO(3), the quaternion automorphism group, is considered as the quark pseudocolour symmetry and the corresponding gauge field is interpreted as the three-gluon-colour field. The other gauge field corresponds to lepton-quark transition and acquires a (large) finite mass under spontaneous breaking of SO(4) gauge symmetry due to the scalar quaternion field

445

Determination of Gravitational Counterterms Near Four Dimensions from RG Equations

The finiteness condition of renormalization gives a restriction on the form of the gravitational action. By reconsidering the Hathrell's RG equations for massless QED in curved space, we determine the gravitational counterterms and conformal anomalies near four dimensions. As conjectured for conformal couplings in 1970s, we show at all orders of the perturbation that they can be combined into two forms only: the square of the Weyl tensor in $D$ dimensions and \\begin{eqnarray*} E_D=G_4 +(D-4)\\chi(D)H^2 -4\\chi(D) \

Hamada, Ken-ji

2014-01-01

446

Supersymmetry Breaks when Gauge Symmetry Breaks: Cybersusy I

This paper summarizes a new approach to supersymmetry breaking in the supersymmetric standard model (SSM). The approach arises from some remarkable features of the BRS cohomology for composite operators in the SSM, and the behaviour of those operators when gauge symmetry is spontaneously broken. A new realization of supersymmetry arises for these operators. This realization is equivalent to the generation of supersymmetry anomalies, though they are not present in the usual s...

Dixon, John

2008-01-01

447

Gauged Nambu-Jona-Lasinio model and axionic QCD string

We propose an axionic QCD string scenario based on the original flux-tube model by Kogut and Susskind, and then incorporate it into a gauged Nambu-Jona-Lasinio (NJL) model. Axial anomaly is studied by a new topological coupling from the string side, and by the 't Hooft vortex from the NJL side, respectively. The nontrivial phase distribution of the quark condensate plays an important role in this scenario.

Xiong, Chi

2014-01-01

448

Running Couplings in Quantum Theory of Gravity Coupled with Gauge Fields

In this paper we study the coupled system of non-abelian gauge fields with higher-derivative gravity. Charge renormalization is investigated in this coupled system. It is found that the leading term in the gauge coupling beta function comes due to interaction of gauge fields with gravitons. This is shown to be a universal quantity in the sense that it doesn't depend on the gauge coupling and the gauge group, but may depend on the other couplings of the action (gravitational and matter). The coupled system is studied at one-loop. It is found that the leading term of gauge beta function is zero at one-loop in four dimensions. The effect of gauge fields on the running of gravitational couplings is investigated. The coupled system of gauge field with higher-derivative gravity is shown to satisfy unitarity when quantum corrections are taken in to account. Moreover, it is found that Newton constant goes to zero at short distances. In this renormalizable and unitary theory of gauge field coupled with higher-derivati...

Narain, Gaurav

2013-01-01

449

Studies in higher-derivative gravitation

International Nuclear Information System (INIS)

In this work two formulations of gravitation in which the action includes the second-derivatives of the metric in a non-trivial fashion are investigated. In the first part, the gauge theory of gravitation proposed by Yang in 1974 is investigated. The implications of coupling the pure space equations to matter sources via the action principle proposed by Yang is studied. It is shown that this action principle does not couple to matter sources in a satisfactory fashion. An earlier study by Fairchild along similar lines is critically examined. It is argued that Fairchild's action functional, and his objections to Yang's gauge approach to gravitation, arise from a not very meaningful analogy with the case of a general gauge field. Also, a conjecture originated in that work is refuted. A modification of Yang's action functional is provided which leads to both the Einstein and Yang field-equations. This system is shown to have non-trivial solutions in the presence of matter. An additional advantage is that the unphysical solutions of the pure space equations can be ruled out. It is shown that the joint system of Einstein and Yang field-equations leads to a physically viable cosmological model based on the Robertson-Walker metric, which satisfies both sets of field-equations. In the second part of this work, the Hamiltonian for pure gravity in Einstein's theory is obtained directly from the Hilbert Lagrangian. Since the Lagrangian depends upon the second-derivatives of the mpends upon the second-derivatives of the metric tensor, first the Hamiltonian formulation for a Lagrangian which may, in general depend upon the Nth-order time derivatives of the dynamical variables is developed

450

Some problems of the theory of gravitation

Leonid Verozub, lverozub@gmail.com Kharkov National University, Kharkov, Ukraine The contemporary observations pose serious challenges to the fundamental physics and astro-physics. We proceed from the equations of gravitation, based on an examination of foundations of the theory. (Ann. Phys. (Leipzig) 17, No. 1, 28 -51 (2008)). Namely, these equations are based on going back to Poincare's ideas about the relativity of geometry of space and time to the properties of measuring instruments, and on the consideration of the geodesic invariance as gauge invariance in the theory of gravitation. These equations do not contradict the observa-tional data, however, lead to two unexpected consequences, which allow you to test the theory: 1. They predict the existence of super-massive compact objects without event horizons, which are an alternative to black holes in the centers of galaxies. 2. They provide a simple and natural explanation for the accelerating expansion of the universe.

Verozub, Leonid

451

Implications of a new light gauge boson for neutrino physics

We study the impact of light gauge bosons on neutrino physics. We show that they can explain the NuTeV anomaly and also escape the constraints from neutrino experiments if they are very weakly coupled and have a mass of a few GeV. Lighter gauge bosons with stronger couplings could explain both the NuTeV anomaly and the positive anomalous magnetic moment of the muon. However, in the simple model we consider in this paper (say a purely vectorial extra U(1) current), they appear to be in conflict with the precise measurements of ??-e, ?e-e elastic scattering cross sections. The surprising agreement that we obtain between our naive model and the NuTeV anomaly for mZ'˜ GeV may be a coincidence. However, we think it is interesting enough to deserve attention and perhaps a more careful analysis, especially since a new light gauge boson is a very important ingredient for the Light Dark Matter scenario.

Bœhm, Céline

2004-09-01

452

Fetal hydrocephalus: Sonographic detection of associated anomalies

International Nuclear Information System (INIS)

Sixty-one consecutive cases of fetal hydrocephalus were reviewed, including 24 seen before 24 menstrual weeks and 37 seen after 24 weeks. Fetal mortality strongly correlated with the presence of concurrent anomalies, excluding meningomyelocele. Sonography correctly identified one or more extra-CNS anomalies in 21 of 27 (78%) fetuses which proved to have severe concurrent anomalies, found at autopsy or on clinical evaluation. No concurrent anomalies (excluding meningomyelocele) were seen in six fetuses with mild anomalies or 28 fetuses without concurrent anomalies. Of 21 fetuses with a meningomyelocele, 18 (86%) were identified by US, and ten had additional anomalies, which were severe in seven

453

We review theory and applications of weak gravitational lensing. After summarising Friedmann-Lemaitre cosmological models, we present the formalism of gravitational lensing and light propagation in arbitrary space-times. We discuss how weak-lensing effects can be measured. The formalism is then applied to reconstructions of galaxy-cluster mass distributions, gravitational lensing by large-scale matter distributions, QSO-galaxy correlations induced by weak lensing, lensing of galaxies by galaxies, and weak lensing of the cosmic microwave background. Contents: Introduction - Cosmological Background - Gravitational Light Deflection - Principles of Weak Gravitational Lensing - Weak Lensing by Galaxy Clusters - Weak Cosmological Lensing - QSO Magnification Bias and Large-Scale Structure - Galaxy-Galaxy Lensing - The Impact of Weak Gravitational Lensing on the Microwave Background Radiation - Summary and Outlook

Bartelmann, M; Bartelmann, Matthias; Schneider, Peter

2001-01-01

454

Gravitational Interactions of Higher-Spin Fermions

We investigate the cubic interactions of a massless higher-spin fermion with gravity in flat space and present covariant 2-s-s vertices, compatible with the gauge symmetries of the system, preserving parity. This explicit construction relies on the BRST deformation scheme that assumes locality and Poincare invariance. Consistent nontrivial cubic deformations exclude minimal gravitational coupling and may appear only with a number of derivatives constrained in a given range. Derived in an independent manner, our results do agree with those obtained from the light-cone formulation or inspired by string theory. We also show that none of the Abelian vertices deform the gauge transformations, while all the non-Abelian ones are obstructed in a local theory beyond the cubic order.

Henneaux, Marc; Rahman, Rakibur

2013-01-01

455

Gravitational Lensing in Astronomy

Deflection of light by gravity was predicted by General Relativity and observationaly confirmed in 1919. In the following decades various aspects of the gravitational lens effect were explored theoretically, among them the possibility of multiple or ring-like images of background sources, the use of lensing as a gravitational telescope on very faint and distant objects, and the possibility to determine Hubble's constant with lensing. Only relatively recently gravitational le...

Wambsganss Joachim

1998-01-01

456

Gravitational wave astronomy is expected to become an observational field within the next decade. First direct detection of gravitational waves is possible with existing terrestrial-based detectors, and highly probable with proposed upgrades. In this three-part lecture series, we give an overview of the field, including material on gravitional wave sources, detection methods, some details of interferometric detectors, data analysis methods, and current results from observational data-taking runs of the LIGO and GEO projects.

CERN. Geneva

2006-01-01

457

We will present a brief introduction to the physics of gravitational waves and their properties. We will review potential astrophysical sources of gravitational waves, and the physics and astrophysics that can be learned from their study. We will survey the techniques and technologies for detecting gravitational waves for the first time, including bar detectors and broadband interferometers, and give a brief status report on the international search effort.

CERN. Geneva HR-RFA

2006-01-01

458

Prenatal Sonographic Diagnosis of Focal Musculoskeletal Anomalies

Focal musculoskeletal anomalies vary, and can manifest as part of a syndrome or be accompanied by numerous other conditions such as genetic disorders, karyotype abnormalities, central nervous system anomalies and other skeletal anomalies. Isolated focal musculoskeletal anomaly does, however, also occur; its early prenatal diagnosis is important in deciding prenatal care, and also helps in counseling parents about the postnatal effects of numerous possible associated anomalies. We have encount...

Ryu, Jung Kyu; Cho, Jeong Yeon; Choi, Jong Sun

2003-01-01

459

Pulsars and Gravitational Waves

The relationship between pulsar-like compact stars and gravitational waves is briefly reviewed. Due to regular spins, pulsars could be useful tools for us to detect ~nano-Hz low-frequency gravitational waves by pulsar-timing array technique; besides, they would also be ~kilo-Hz high-frequency gravitational wave radiators because of their compactness. The wave strain of an isolate pulsar depends on the equation state of cold matter at supra-nuclear densities. Therefore, a real detection of gravitational wave should be very meaningful in gravity physics, micro-theory of elementary strong interaction, and astronomy.

Lee, K J; Qiao, G J

2011-01-01

460

International Nuclear Information System (INIS)

When two gravitating bodies reside in a material medium, Newton's law of universal gravitation must be modified to account for the presence of the medium. A modified expression of Newton's law is known in the literature, but lacks a clear connection with existing gravitational theory. Newton's law in the presence of a homogeneous material medium is herein derived on the basis of classical, Newtonian gravitational theory and by a general relativistic use of Archimedes' principle. It is envisioned that the techniques presented herein will be most useful to graduate students and those undergraduate students having prior experience with vector analysis and potential theory.

461

Microcomputerized neutron moisture gauge

International Nuclear Information System (INIS)

A microcomputerized neutron moisture gauge is introduced. This gauge consists of a neutron moisture sensor and instruments. It is developed from the neutron moisture gauge for concrete mixer. A TECH-81 single card microcomputer is used for count, computation and display. It has the function of computing compensated quantity of sand. It can acquire the data from several neutron sensors by the multichanneling sampling, therefore it can measure moisture values of sand in several hoppers simultaneously. The precision of the static state calibration curve is 0.24% wt. The error limits of the dynamic state check is < 0.50% wt

462

Renormalization of gauge theories

International Nuclear Information System (INIS)

Gauge theories are characterized by the Slavnov identities which express their invariance under a family of transformations of the supergauge type which involve the Faddeev Popov ghosts. These identities are proved to all orders of renormalized perturbation theory, within the BPHZ framework, when the underlying Lie algebra is semisimple and the gauge function is chosen to be linear in the fields in such a way that all fields are massive. An example, the SU2 Higgs Kibble model is analyzed in detail: the asymptotic theory is formulated in the perturbative sense, and shown to be reasonable, namely, the physical S operator is unitary and independent from the parameters which define the gauge function

463

Loop quantum gravity corrections to gravitational wave dispersion

International Nuclear Information System (INIS)

Cosmological tensor perturbations equations are derived for Hamiltonian cosmology based on Ashtekar's formulation of general relativity, including typical quantum gravity effects in the Hamiltonian constraint as they are expected from loop quantum gravity. This translates to corrections of the dispersion relation for gravitational waves. The main application here is the preservation of causality which is shown to be realized due to the absence of anomalies in the effective constraint algebra used

464

Conformal Anomaly Actions and Dilaton Interactions

A number of computational results concerning quantum conformal symmetry is presented. After a review of the connection between conformal symmetry for a Lagrangian field theory in flat space and Weyl symmetry for the same system embedded in a gravitational background, which is discussed in chapter 1, in chapter 2 the 3 energy momentum tensors correlation function is explicitly computed in three free field theories in 4 dimensions; the result is given for two of the three operators on the mass-shell. In chapter 3 a general method to map Green functions built in position space on the ground of symmetry requirements to momentum space, where they can be computed in terms of Feynman diagrams, is developed and discussed: an "integrability" condition, allowing to decide whether a certain correlator can exist within a Lagrangian theory, is derived. Chapter 4 discusses the possible phenomenological implications of the conformal anomaly pole which shows up in the 3 point Green function of one energy momentum tensor with...

Serino, Mirko

2014-01-01

465

Directory of Open Access Journals (Sweden)

Full Text Available Nonlinear effect of the gravitation field of spherically symmetric mass on the gravitational coefficient G has been analysed. In frame of the approaches of parametric optics and gravitation nonlinearity we have shown that the gravitation field of spherically symmetric mass can lead to changes in the gravitational coefficient G.

R. Vlokh

2006-12-01

466

Nonlinear effect of the gravitation field of spherically symmetric mass on the gravitational coefficient G has been analysed. In frame of the approaches of parametric optics and gravitation nonlinearity we have shown that the gravitation field of spherically symmetric mass can lead to changes in the gravitational coefficient G.

Vlokh, R.; Kostyrko, M.

2006-01-01

467

Ward identities in a general axial gauge. II. Quantum gravity

We have calculated the pole part of the one-loop graviton self-energy in the noncovariant axial gauge n????=0, n2?0, where ??? is the physical gravition field and n? is an arbitrary but constant vector. It is shown that the self-energy is, unexpectedly, both nontransverse and n? dependent, even though it satisfies the correct gravitational Ward identity. This Ward identity is found to contain a term corresponding to a "pincer" Feynman diagram which is directly responsible for the nontransversality of the graviton self-energy. Ghost particles do not contribute to the graviton amplitude. All aixal-gauge integrals are consistently evaluated in the context of dimensional regularization and by applying the principal-value prescription.

Capper, D. M.; Leibbrandt, George

1982-02-01

468

The Standard Model calculation of $H\\rightarrow\\gamma\\gamma$ has the curious feature of being finite but regulator-dependent. While dimensional regularization yields a result which respects the electromagnetic Ward identities, additional terms which violate gauge invariance arise if the calculation is done setting $d=4$. This discrepancy between the $d=4-\\epsilon$ and $d=4$ results is recognized as a true ambiguity which must be resolved using physics input; as dimensional regularization respects gauge invariance, the $d=4-\\epsilon$ calculation is accepted as the correct SM result. However, here we point out another possibility; working in analogy with the gauge chiral anomaly, we note that it is possible that the individual diagrams do violate the electromagnetic Ward identities, but that the gauge-invariance-violating terms cancel when all contributions to $H\\rightarrow\\gamma\\gamma$, both from the SM and from new physics, are included. We thus examine the consequences of the hypothesis that the $d=4$ calcul...

de Gouvea, Andre; Vega-Morales, Roberto

2013-01-01

469

International Nuclear Information System (INIS)

Present and future prospects for the discovery of new gauge bosons, Z' and W', are reviewed. Particular attention is paid to hadron and e+e- collider searches for the W' of the Left-Right Symmetric Model

470

QCD can be formulated using any gauge group. One particular interesting choice is to replace SU(3) by the exceptional group G2. Conceptually, this group is the simplest group with a trivial center. It thus permits to study the conjectured relevance of center degrees of freedom for QCD. Practically, since all its representation are real, it is possible to perform lattice simulations for this theory also at finite baryon densities. It is thus an excellent environment to test methods and to investigate general properties of gauge theories at finite densities. We review the status of our understanding of gauge theories with the gauge group G2, including Yang-Mills theory, Yang-Mills-Higgs theory, and QCD both in the vacuum and in the phase diagram.

Maas, Axel

2012-01-01

471

Gravitational effects in field gravitation theory

International Nuclear Information System (INIS)

The possibilities to describe various gravitation effects of field gravitation theory (FGT) are considered. Past-Newtonian approximation of the FGT has been constructed and on the basis of this approximation it has been shown that the field theory allows one to describe the whole set of experimental facts. The comparison of post-Newtonian parameters in FGT with those in the Einstein's theory makes it clear that these two; theories are undistinguishable from the viewpoint of any experiments, realized with post-Newtonian accuracy. Gravitational field of an island type source with spherically symmetrical distribution of matter and unstationary homogeneous model of Universe, which allows to describe the effect of cosmological red shift, are considered

472

Lattice gauge theory, gauge-gravity duality, and Coulomb constant in five dimensions

The purpose of this paper is to perform a quantitative check of gauge theory-gravity duality in a nonconformal, nonsupersymmetric context. In order to do so we define k5, an object extracted from the Wilson loop, that plays the role of Coulomb’s constant for SU(N) gauge theories in five dimensions, and we argue that one of its virtues is that it could be minimally sensitive to N. This allows us to compute k5 on one hand from the gravitational backreation of a large number N of D4-branes, and on the other from a lattice mean-field expansion for N=2. We find a 2% numerical agreement between the two approaches.

Irges, Nikos

2012-03-01

473

Axial anomaly and index theorem for Dirac-Kaehler fermions

International Nuclear Information System (INIS)

Some aspects of topological influence on gauge field theory are analysed, considering the geometry and differential topology methods. A review of concepts of differential forms, fibered spaces, connection and curvature, showing an interpretation of gauge theory in this context, is presented. The question of fermions, analysing in details the Dirac-Kaehler which fermionic particle is considered a general differential form, is studied. It is shown how the explicit expressions in function of the Dirac spinor components vary with the Dirac matrix representation. The Dirac-Kahler equation contains 4 times (in 4 dimensions) the Dirac equation, each particle being associated an ideal at left of the algebra of general differential forms. These ideals and the SU(4) symmetry among them are also studied on the point of view of spinors and, the group of reduction to one of the ideals is identified as the Cartan subalgebra of this SU(4). Finally, the axial anomaly is calculated through the functional determinant given by the Dirac-Kaehler operator. The regularization method is the Seeley's coefficients. From that results a comparison of the index theorems for the twisted complexes of signature and spin, which proportionality is given by the number of the algebra ideals contained in the Dirac-Kaehler equation and which also manifests in the respective axial anomaly equations. (L.C.)

474

Parastatistics and gauge symmetries

International Nuclear Information System (INIS)

It is shown that the copy of the only SO(3) - gauge Yang-Mills Lagrangian can be constructed in the Green parafield theory. Thus, the Greenberg paraquarks are not equivalent to coloured quarks obeying SU(3)sub(c). Peculiarities of gauge SO(3) are considered and its possible application as the exact subgroup of the broken SU(3)sub(c) is indicated

475

We propose a reformulation of electrodynamics in terms of a {\\it physical} vector potential entirely free of gauge ambiguities. Quantizing the theory leads to a propagator that is gauge invariant by construction in this reformulation, in contrast to the standard photon propagator. Coupling the theory to a charged Abelian Higgs field leads at the quantum level to a one loop effective potential which realizes the Coleman-Weinberg mechanism of mass generation, thus resolving th...

Majumdar, Parthasarathi; Bhattacharjee, Srijit

2009-01-01

476

International Nuclear Information System (INIS)

Assuming that a lattice gauge theory describes a fundamental attribute of Nature, it should be pointed out that such a theory in the form of a gauge glass is a weaker assumption than a regular lattice model in as much as it is not constrained by the imposition of translational invariance; translational invariance is, however, recovered approximately in the long wavelength or continuum limit. (orig./WL)

477

One of the main features of covariant theories, in particular general relativity, is that the field equation possesses gauge freedom associated with global diffeomorphisms of the underlying manifold. I shall explain here how the hole argument is a reflection of this gauge freedom. Finally I shall point out some implications of the hole argument and extend the hole argument to the case of permutable theories. As covariant theories provides a general mathematical framework f...

Iftime, M. D.

2006-01-01

478

Minimal seesaw as an ultraviolet insensitive cure for the problems of anomaly mediation

International Nuclear Information System (INIS)

We show that an intermediate scale supersymmetric left-right seesaw scenario with automatic R-parity conservation can cure the problem of tachyonic slepton masses that arise when supersymmetry is broken by anomaly mediation, while preserving ultraviolet insensitivity. The reason for this is the existence of light B-L=2 Higgses with Yukawa couplings to the charged leptons. We find these theories to have distinct predictions compared to the usual mSUGRA and gauge mediated models as well as the minimal anomaly mediated supersymmetry breaking models. Such predictions include a condensed gaugino mass spectrum and possibly a correspondingly condensed sfermion spectrum.

479

Shedding light on the $b\\to s$ anomalies with a dark sector

The LHCb collaboration has recently reported on some anomalies in $b\\to s$ transitions. In addition to discrepancies with the Standard Model (SM) predictions in some angular observables and branching ratios, an intriguing hint for lepton universality violation was found. Here we propose a simple model that extends the SM with a dark sector charged under an additional $U(1)$ gauge symmetry. The spontaneous breaking of this symmetry gives rise to a massive $Z^\\prime$ boson, which communicates the SM particles with a valid dark matter candidate, while solving the $b\\to s$ anomalies with contributions to the relevant observables.

Sierra, D Aristizabal; Vicente, Avelino

2015-01-01

480

B-L assisted anomaly mediation and the radiative B-L symmetry breaking

International Nuclear Information System (INIS)

Anomaly mediated supersymmetry breaking implemented in the minimal supersymmetric standard model (MSSM) is known to suffer from the tachyonic slepton problem leading to breakdown of electric charge conservation. We show however that when MSSM is extended to explain small neutrino masses by gauging the B-L symmetry, the slepton masses can be positive due to the Z' mediation contributions. We obtain various soft supersymmetry breaking mass spectra, which are different from those obtained in the conventional anomaly mediation scenario. Then there would be a distinct signature of this scenario at the LHC

481

Hawking radiation from the charged and magnetized BTZ black hole via covariant anomaly

International Nuclear Information System (INIS)

This paper discusses Hawking radiation from the charged and magnetized Bañados–Teitelboim–Zanelli (BTZ) black hole from the viewpoint of anomaly, initiated by Robinson and Wilczek recently. It reconstructs the electromagnetic field tensor and the Lagrangian of the field corresponding to the source with electric and magnetic charges to redefine an equivalent charge and gauge potential. It employs the covariant anomaly cancellation method to determine the compensating fluxes of charge flow and energy-momentum tensor, which are shown to match with those of the 2-dimensional blackbody radiation at the Hawking temperature exactly. (general)

482

An Anzatz about Gravity, Cosmology, and the Pioneer Anomaly

International Nuclear Information System (INIS)

The Pulsar 1913+16 binary system may represent a 'young' binary system where previously it is claimed that the dynamics are due to either a third body or a gravitational vortex. Usually a binary system's trajectory could reside in a single ellipse or circular orbit; the double ellipse implies that the 1913+16 system may be starting to degenerate into a single elliptical trajectory. This could be validated only after a considerably long time period. In a majority of binary star systems, the weights of both stars are claimed by analysis to be the same. It may be feasible that the trajectory of the primary spinning star could demonstrate repulsive gravitational effects where the neutron star's high spin rate induces a repulsive gravitational source term that compensates for inertia. If true, then it provides evidence that angular momentum may be translated into linear momentum as a repulsive source that has propulsion implications. This also suggests mass differences may dictate the neutron star's spin rate as an artifact of a natural gravitational process. Moreover, the reduced matter required by the 'dark' mass hypothesis may not exist but these effects could be due to repulsive gravity residing in rotating celestial bodies.The Pioneer anomaly observed on five different deep-space spacecraft, is the appearance of a constant gravitational force directed toward the sun. Pioneer spacecraft data reveals that a vortex-like magnetic field exists emanating from the sun. The sfield exists emanating from the sun. The spiral arms of the Sun's magnetic vortex field may be causal to this constant acceleration. This may profoundly provide a possible experimental verification on a cosmic scale of Gertsenshtein's principle relating gravity to electromagnetism. Furthermore, the anomalous acceleration may disappear once the spacecraft passes out into a magnetic spiral furrow, which is something that needs to be observed in the future. Other effects offer an explanation from space-time geometry to the Yarkovsky thermal effects are discussed.

483

Unified gauge models and the very early Universe

International Nuclear Information System (INIS)

For an arbitrary unified gauge model the free energy, including the exchange and correlation terms, is calculated at superhigh temperatures. The results are particularized in the framework of the realistic SU(5) model and then improved by means of the renormalization group. The equation of state obtained is applied to description of the expansion of the Universe at very high temperatures. It is found that the temperature of the fossil gravitational radiation must be of the order 1 0K

484

A gauge theoretic approach to elasticity with microrotations

We formulate elasticity theory with microrotations using the framework of gauge theories, which has been developed and successfully applied in various areas of gravitation and cosmology. Following this approach, we demonstrate the existence of particle-like solutions. Mathematically this is due to the fact that our equations of motion are of Sine-Gordon type and thus have soliton type solutions. Similar to Skyrmions and Kinks in classical field theory, we can show explicitly...

Boehmer, Christian G.; Obukhov, Yuri N.

2010-01-01

485

A gauge theoretic approach to elasticity with microrotations

We formulate elasticity theory with microrotations using the framework of gauge theories, which has been developed and successfully applied in various areas of gravitation and cosmology. Following this approach, we demonstrate the existence of particle-like solutions. Mathematically this is due to the fact the our equations of motion are of Sine-Gordon type and thus have soliton type solutions. Similar to Skyrmions and Kinks in classical field theory, we can show explicitly that these solutions have a topological origin.

Boehmer, Christian G

2010-01-01

486

An Intelligent Strain Gauge with Debond Detection and Temperature Compensation

The harsh rocket propulsion test environment will expose any inadequacies associated with preexisting instrumentation technologies, and the criticality for collecting reliable test data justifies investigating any encountered data anomalies. Novel concepts for improved systems are often conceived during the high scrutiny investigations by individuals with an in-depth knowledge from maintaining critical test operations. The Intelligent Strain Gauge concept was conceived while performing these kinds of activities. However, the novel concepts are often unexplored even if it has the potential for advancing the current state of the art. Maturing these kinds of concepts is often considered to be a tangential development or a research project which are both normally abandoned within the propulsion-oriented environment. It is also difficult to justify these kinds of projects as a facility enhancement because facility developments are only accepted for mature and proven technologies. Fortunately, the CIF program has provided an avenue for bringing the Intelligent Strain Gauge to fruition. Two types of fully functional smart strain gauges capable of performing reliable and sensitive debond detection have been successfully produced. Ordinary gauges are designed to provide test article data and they lack the ability to supply information concerning the gauge itself. A gauge is considered to be a smart gauge when it provides supplementary data relating other relevant attributes for performing diagnostic function or producing enhanced data. The developed strain gauges provide supplementary signals by measuring strain and temperature through embedded Karma and nickel chromium (NiCr) alloy elements. Intelligently interpreting the supplementary data into valuable information can be performed manually, however, integrating this functionality into an automatic system is considered to be an intelligent gauge. This was achieved while maintaining a very low mass. The low mass enables debond detection and temperature compensation to be performed when the gauge is utilized on small test articles. It was also found that the element's mass must be relatively small to avoid overbearing the desired thermal dissipation characteristics. Detecting the degradation of a gauge s bond was reliably achieved by correlating thermal dissipation with the bond s integrity. This was accomplished by precisely coupling a NiCr element with a Karma element for accurately interjecting and quantifying thermal energy. A finite amount of thermal energy is consistently placed in the gauge by electrically powering the NiCr element. The energy will only be temporarily stored before it begins to dissipate into the surrounding structure through the gauge bond. The ability to transmit the energy into the structure becomes greatly inhibited by any discontinuity in the bond s substrate. Therefore, the way the thermal dissipation occurs will reveal even the slightest change in the integrity of the bond.

Jensen, Scott L.

2012-01-01

487

On interpretation of gravitation

International Nuclear Information System (INIS)

This paper is concerned with the origin of gravitation. Here, an attempt has been made to show that gravitation is an effect of interaction of the magnetic field and the electric current produced by rotation of heavenly bodies on their axes. (author). 3 refs

488

Relativistic gravitation theory

International Nuclear Information System (INIS)

On the basis of the special relativity and geometrization principle a relativistic gravitation theory (RGT) is unambiguously constructed with the help of a notion of a gravitational field as a physical field in Faraday-Maxwell spirit, which posesses energy momentum and spins 2 and 0. The source of gravitation field is a total conserved energy-momentum tensor for matter and for gravitation field in Minkowski space. In the RGT conservation laws for the energy momentum and angular momentum of matter and gravitational field hold rigorously. The theory explains the whole set of gravitation experiments. Here, due to the geometrization principle the Riemannian space is of a field origin since this space arises effectively as a result of the gravitation field origin since this space arises effectively as a result of the gravitation field action on the matter. The RGT astonishing prediction is that the Universe is not closed but ''flat''. It means that in the Universe there should exist a ''missing'' mass in some form of matter

489

Earth Magnetic Anomaly Grid Released

An Earth Magnetic Anomaly Grid (EMAG2) compiled from satellite, ship, and airborne magnetic measurements during a 2-year international collaborative effort was released in February 2009. Magnetic anomaly maps provide insights into the subsurface structure and composition of the Earths crust. They are widely used in the geological sciences and in resource exploration. Furthermore, the global magnetic map is useful in science education to illustrate plate tectonics, crustal interaction with the deep mantle, and other aspects of Earth evolution. Distinct patterns and magnetic signatures on magnetic anomaly maps can be attributed to the formation (seafloor spreading) and destruction (subduction zones) of oceanic crust, the formation of continental crust by accretion of terranes to cratonic areas, and large-scale volcanism.

Maus, Stefan

2009-07-01

490

Propellant Gauging for Exploration

This paper presents a brief overview of propellant gauging needs and requirements in the context of lunar exploration missions defined by the Exploration Systems Architecture Study (ESAS) report. A timeline for the development and testing of gauging technologies, and a few key design review dates are presented. A lunar exploration mission scenario is discussed which aids in defining the propellant gauging needs. The fleet of new exploration vehicles includes the Ares I and Ares V launch vehicles, Earth Departure Stage (EDS), Lunar Surface Access Module (LSAM) ascent and descent stages, and the Orion Crew Exploration Vehicle (CEV). The liquid propellant choices are currently oxygen - hydrogen for the launch vehicles, the EDS, and LSAM descent module; oxygen - methane for LSAM ascent module; and monomethylhydrazine nitrogen tetroxide (MMH-NTO) for the CEV. Estimated tank sizes, temperatures, pressures, and storage durations are presented. A baseline propellant gauging system is proposed that is based on high Technology Readiness Level (TRL) gauging technologies. In order to be considered for use on the new exploration vehicles, any new gauging technologies will have to show a clear benefit over the baseline methods in terms of performance and/or cost.

Zimmerli, Gregory A.

2007-01-01

491

We present a unified framework to describe lattice gauge theories by means of tensor networks: this framework is efficient as it exploits the high amount of local symmetry content native of these systems describing only the gauge invariant subspace. Compared to a standard tensor network description, the gauge invariant one allows to speed-up real and imaginary time evolution of a factor that is up to the square of the dimension of the link variable. The gauge invariant tensor network description is based on the quantum link formulation, a compact and intuitive formulation for gauge theories on the lattice, and it is alternative and can be combined with the global symmetric tensor network description. We present some paradigmatic examples that show how this architecture might be used to describe the physics of condensed matter and high-energy physics systems. Finally, we present a cellular automata analysis which estimates the gauge invariant Hilbert space dimension as a function of the number of lattice sites...

Silvi, Pietro; Calarco, Tommaso; Montangero, Simone

2014-01-01

492

We present a unified framework to describe lattice gauge theories by means of tensor networks: this framework is efficient as it exploits the high local symmetry content native to these systems by describing only the gauge invariant subspace. Compared to a standard tensor network description, the gauge invariant model allows one to increase real and imaginary time evolution up to a factor that is square of the dimension of the link variable. The gauge invariant tensor network description is based on the quantum link formulation, a compact and intuitive formulation for gauge theories on the lattice, which is alternative to and can be combined with the global symmetric tensor network description. We present some paradigmatic examples that show how this architecture might be used to describe the physics of condensed matter and high-energy physics systems. Finally, we present a cellular automata analysis which estimates the gauge invariant Hilbert space dimension as a function of the number of lattice sites that might guide the search for effective simplified models of complex theories.

Silvi, Pietro; Rico, Enrique; Calarco, Tommaso; Montangero, Simone

2014-10-01