scholarly journals Multiple choice of gauge generators and consistency of interactions

2014 ◽  
Vol 29 (31) ◽  
pp. 1450167 ◽  
Author(s):  
S. L. Lyakhovich ◽  
A. A. Sharapov
Keyword(s):  
Gauge Symmetry ◽  
Simple Model ◽  
Degrees Of Freedom ◽  
Multiple Choice ◽  
Gravity Models ◽  
Coupling Constant ◽  
Free Theory ◽  
Gauge Symmetries

It is usually assumed that any consistent interaction either deforms or retains the gauge symmetries of the corresponding free theory. We propose a simple model where an obvious irreducible gauge symmetry does not survive an interaction, while the interaction is consistent as it preserves the number of physical degrees of freedom. The model turns out admitting a less obvious reducible set of gauge generators which is compatible with the interaction and smooth in coupling constant. Possible application to gravity models is discussed.

scholarly journals Background independence in string theory

2018 ◽  
Vol 27 (14) ◽  
pp. 1847026
Author(s):  
Olaf Hohm
Keyword(s):  
Gauge Symmetry ◽  
String Theory ◽  
Degrees Of Freedom ◽  
Einstein Gravity ◽  
Background Independence ◽  
Gauge Symmetries ◽  
Higher Derivative ◽  
Invariant Formulation

I discuss various aspects of background independence in the context of string theory, for which so far we have no manifestly background independent formulation. After reviewing the role of background independence in classical Einstein gravity, I discuss recent results implying that there is a conflict in string theory between manifest background independence and manifest duality invariance when higher-derivative corrections are included. The resolution of this conflict requires the introduction of new gauge degrees of freedom together with an enlarged gauge symmetry. This suggests more generally that a manifestly background independent and duality invariant formulation of string theory requires significantly enhanced gauge symmetries.

scholarly journals DYNAMICAL SYMMETRY BREAKING IN A MINIMAL 3-3-1 MODEL

2012 ◽  
Vol 27 (26) ◽  
pp. 1250156 ◽  
Author(s):  
A. DOFF ◽  
A. A. NATALE
Keyword(s):  
Gauge Symmetry ◽  
Symmetry Breaking ◽  
Dynamical Symmetry ◽  
Mass Scale ◽  
Coupling Constant ◽  
Walking Behavior ◽  
Dynamical Symmetry Breaking ◽  
Dynamical Generation ◽  
Breaking Scale

The gauge symmetry breaking in some versions of 3-3-1 models can be implemented dynamically because at the scale of a few TeVs the U(1)X coupling constant becomes strong. In this work, we consider the dynamical symmetry breaking in a minimal SU(3) TC × SU(3)L × U(1)X model, where we propose a new scheme to cancel the chiral anomalies, including two-index symmetric (6) technifermions, which incorporates naturally the walking behavior in the Technicolor (TC) sector. The composite scalar content of the model is minimal and all the symmetry breaking is implemented by a multiplet of technifermions. The choice of TC representations not only provides the anomaly cancelation with a walking behavior, but is crucial to promote the model's full dynamical symmetry breaking. We consider the dynamical generation of technigluon masses and, depending on the 3-3-1 symmetry breaking scale (μ331), we verify that the technigluon mass is strongly linked to the Z′ mass scale, for instance, if μ331 = 1 TeV , we have MZ′ > 1 TeV only if M TG < 350 GeV .

Optical properties of complex oxides: Vanadate ladders and related inorganic nanotubes

2002 ◽  
Vol 12 (9) ◽  
pp. 355-355
Author(s):  
J. L. Musfeldt ◽  
A. B. Sushkov ◽  
J. Jegoudez ◽  
A. Revcolevschi ◽  
P. Millet ◽  
...  
Keyword(s):  
Phase Boundary ◽  
Degrees Of Freedom ◽  
Energy Scale ◽  
Coupling Constant ◽  
Field Phase ◽  
Inorganic Nanotubes ◽  
Small Coupling ◽  
Small Coupling Constant ◽  
Na Ions ◽  
T Phase

Optical spectroscopy is a sensitive probe of charge, spin, and lattice degrees of freedom. In this talk, I will detail our magneto-optical work on alpha'-NaV2O5, a prototypical ladder material, as well as the new Na2V3O7 nanotubes. Using changes in electronic structure with temperature and applied magnetic field, we have mapped out the H-T phase diagram of alpha'-NaV2O5. We find a temperature independent phase boundary at 27 T which persists above Tc (34 K), a kink in Tc(H) near 27 T, and H$\wedge $2 behavior of Tc(H) in the high field phase with an unusually small coupling constant. The energy scale of Tc and the newly discovered phase boundary at Hc (27 T) are identical. Confinement effects are investigated in the related nanotubes. Results include a larger gap than in analogous bulk materials as well as a low-energy rattling mode, which corresponds to the motion of Na+ ions inside the nanotube.

scholarly journals Hamiltonian formalism for nonlocal gravity models

2022 ◽  
Author(s):  
Pawan Joshi ◽  
Utkarsh Kumar ◽  
Sukanta Panda
Keyword(s):  
Ricci Tensor ◽  
Degrees Of Freedom ◽  
Hamiltonian Formalism ◽  
Riemann Tensor ◽  
Ricci Scalar ◽  
Gravity Models ◽  
Lagrangian Formalism ◽  
Acceleration Of The Universe ◽  
Nonlocal Action ◽  
The Universe

Nonlocal gravity models are constructed to explain the current acceleration of the universe. These models are inspired by the infrared correction appearing in Einstein–Hilbert action. Here, we develop the Hamiltonian formalism of a nonlocal model by considering only terms to quadratic order in Riemann tensor, Ricci tensor and Ricci scalar. We show how to count degrees of freedom using Hamiltonian formalism including Ricci tensor and Ricci scalar terms. In this model, we have also worked out with a choice of a nonlocal action which has only two degrees of freedom equivalent to GR. Finally, we find the existence of additional constraints in Hamiltonian required to remove the ghosts in our full action. We also compare our results with that of obtained using Lagrangian formalism.

scholarly journals Spontaneously Broken Gauge Symmetry in a Bose Gas with Constant Particle Number

2017 ◽  
Vol 16 (01) ◽  
pp. 1750009
Author(s):  
A. Schelle
Keyword(s):  
Gauge Symmetry ◽  
Particle Number ◽  
Present Model ◽  
Phase Distribution ◽  
Equations Of Motion ◽  
Einstein Condensation ◽  
Bose Einstein Condensation ◽  
Gauge Symmetries ◽  
Non Local ◽  
Bose Einstein

The interplay between spontaneously broken gauge symmetries and Bose–Einstein condensation has long been controversially discussed in science, since the equations of motion are invariant under phase transformations. Within the present model, it is illustrated that spontaneous symmetry breaking appears as a non-local process in position space, but within disjoint subspaces of the underlying Hilbert space. Numerical simulations show that it is the symmetry of the relative phase distribution between condensate and non-condensate quantum fields which is spontaneously broken when passing the critical temperature for Bose–Einstein condensation. Since the total number of gas particles remains constant over time, the global U(1)-gauge symmetry of the system is preserved.

scholarly journals COMMENTS ON REGULARIZATION AMBIGUITIES AND LOCAL GAUGE SYMMETRIES

2005 ◽  
Vol 20 (25) ◽  
pp. 1933-1938 ◽  
Author(s):  
R. CASANA ◽  
B. M. PIMENTEL
Keyword(s):  
Field Theory ◽  
Gauge Symmetry ◽  
Quantum Level ◽  
Local Gauge ◽  
Gauge Symmetries ◽  
Local Gauge Symmetry ◽  
Coupling Parameters

We study the regularization ambiguities in an exact renormalized (1 +1)-dimensional field theory. We show a relation between the regularization ambiguities and the coupling parameters of the theory as well as their role in the implementation of a local gauge symmetry at quantum level.

scholarly journals 3+1DMassless Weyl Spinors from Bosonic Scalar-Tensor Duality

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Andrea Amoretti ◽  
Alessandro Braggio ◽  
Giacomo Caruso ◽  
Nicola Maggiore ◽  
Nicodemo Magnoli
Keyword(s):  
Dirac Equation ◽  
Charge Density ◽  
Dimensional Reduction ◽  
Degrees Of Freedom ◽  
Planar Boundary ◽  
Weyl Spinor ◽  
Bf Theory ◽  
Free Theory ◽  
Tomographic Representation

We consider the fermionization of a bosonic-free theory characterized by the3+1Dscalar-tensor duality. This duality can be interpreted as the dimensional reduction, via a planar boundary, of the4+1Dtopological BF theory. In this model, adopting the Sommerfield tomographic representation of quantized bosonic fields, we explicitly build a fermionic operator and its associated Klein factor such that it satisfies the correct anticommutation relations. Interestingly, we demonstrate that this operator satisfies the massless Dirac equation and that it can be identified with a3+1DWeyl spinor. Finally, as an explicit example, we write the integrated charge density in terms of the tomographic transformed bosonic degrees of freedom.

scholarly journals TOPOLOGICALLY MASSIVE NON-ABELIAN THEORY: SUPERFIELD APPROACH

2011 ◽  
Vol 26 (25) ◽  
pp. 4419-4450 ◽  
Author(s):  
S. KRISHNA ◽  
A. SHUKLA ◽  
R. P. MALIK
Keyword(s):  
Gauge Theory ◽  
Gauge Symmetry ◽  
Brst Symmetry ◽  
Gauge Transformations ◽  
Abelian Theory ◽  
Gauge Symmetries ◽  
Vector Gauge ◽  
Symmetry Transformations ◽  
Brst Invariance ◽  
Lagrangian Densities

We apply the well-established techniques of geometrical superfield approach to Becchi–Rouet–Stora–Tyutin (BRST) formalism in the context of four (3+1)-dimensional (4D) dynamical non-Abelian 2-form gauge theory by exploiting its inherent "scalar" and "vector" gauge symmetry transformations and derive the corresponding off-shell nilpotent and absolutely anticommuting BRST and anti-BRST symmetry transformations. Our approach leads to the derivation of three (anti-)BRST invariant Curci–Ferrari (CF)-type restrictions that are found to be responsible for the absolute anticommutativity of the BRST and anti-BRST symmetry transformations. We derive the coupled Lagrangian densities that respect the (anti-)BRST symmetry transformations corresponding to the "vector" gauge transformations. We also capture the (anti-)BRST invariance of the CF-type restrictions and coupled Lagrangian densities within the framework of our superfield approach. We obtain, furthermore, the off-shell nilpotent (anti-)BRST symmetry transformations when the (anti-)BRST symmetry transformations corresponding to the "scalar" and "vector" gauge symmetries are merged together. These off-shell nilpotent "merged" (anti-)BRST symmetry transformations are, however, found to be non-anticommuting in nature.

scholarly journals ELECTROMAGNETIC DUALITY ON THE LIGHT-FRONT IN THE PRESENCE OF EXTERNAL SOURCES

2000 ◽  
Vol 15 (30) ◽  
pp. 4739-4748 ◽  
Author(s):  
ASMITA MUKHERJEE ◽  
SOMDATTA BHATTACHARYA
Keyword(s):  
Degrees Of Freedom ◽  
Transverse Field ◽  
Light Front ◽  
Duality Transformation ◽  
Hamiltonian Density ◽  
Free Theory ◽  
External Sources ◽  
Normal Light ◽  
The Right ◽  
Dynamical Field

We investigate the issue of electromagnetic duality on the light-front. We work with Zwanziger's theory of electric and magnetic sources which is appropriate for treating duality. When quantized on the light-front in the light-front gauge, this theory yields two independent phase space degrees of freedom, namely the two transverse field components, the right number to describe the gauge field sector of normal light-front QED and also the appropriate commutator between them. The electromagnetic duality transformation formulated in terms of them is similar in form to the Susskind transformation proposed for the free theory, provided one identifies them as the dynamical field components of the photon on the light-front in the presence of magnetic sources. The Hamiltonian density written in terms of these components is invariant under the duality transformation.

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