English
Related papers

Related papers: No-birefringence conditions for spacetime

200 papers

Motivated by an apparent puzzle of the light-front vacua incompatible with the axial anomaly, we have considered the two-dimensional massless Schwinger model for an arbitrary interpolating angle of the quantization surface. By examining…

High Energy Physics - Phenomenology · Physics 2009-10-28 Chueng-Ryong Ji , Soo-Jong REY

It is proven that the usual quadratic general-covariant Lagrangian for the Dirac field leads to a symmetric, divergence-free energy-momentum tensor in the standard Riemannian framework of space-time without torsion, provided the tetrad…

General Relativity and Quantum Cosmology · Physics 2008-02-03 Ludger Hannibal

Using complexified quaternions, a formalism without Lorentz frames, and therefore also without vierbeins, for dealing with tensor and spinor fields in curved spacetime is presented. A local U(1) gauge symmetry, which, it is speculated,…

Mathematical Physics · Physics 2015-05-13 John Fredsted

The residual gauge freedom within the null quasi-spherical coordinate condition is studied, for spacetimes admitting an expanding, shear-free null foliation. The freedom consists of a boost and rotation at each coordinate sphere,…

General Relativity and Quantum Cosmology · Physics 2009-10-30 Robert Bartnik

We consider both the co-ordinates and momenta to be non-commutative and define a non-commutative version of Lorentz symmetry which has a smooth limit to the standard Lorentz symmetry. The Poincar\acute{e} algebra in this spacetime has also…

High Energy Physics - Theory · Physics 2008-12-31 Pulak Ranjan Giri , T. Shreecharan

We apply the complex de Broglie-Bohm formulation of quantum mechanics [1] to a spatially closed homogeneous and isotropic early Universe whose matter content are radiation and dust perfect fluids. We then show that an expanding classical…

General Relativity and Quantum Cosmology · Physics 2016-10-12 M. Fathi , S. Jalalzadeh , P. V. Moniz

We construct supersymmetric quantum mechanics in terms of two real supercharges on noncommutative space in arbitrary dimensions. We obtain the exact eigenspectra of the two and three dimensional noncommutative superoscillators. We further…

High Energy Physics - Theory · Physics 2009-01-07 Pijush K. Ghosh

We propose a classical action for the motion of massless Weyl fermions in a background gauge field in (2N+1)+1 spacetime dimensions. We use this action to derive the collisionless Boltzmann equation for a gas of such particles, and show how…

High Energy Physics - Theory · Physics 2015-06-16 Vatsal Dwivedi , Michael Stone

Nonreciprocal photonic devices play a significant role in regulating the propagation of electromagnetic waves. Here we theoretically investigate the nonreciprocal properties of transverse magnetic modes in a one-dimensional graphene-based…

Optics · Physics 2020-12-02 D. P. Huang , K. Y. Xu

In this article, we investigate the gravitational field of a charged, non-vacuum, non-rotating, spherically symmetric body of mass $M$ assuming a static solution to the Einstein-Maxwell field equations. We demonstrate that the…

General Relativity and Quantum Cosmology · Physics 2024-04-16 Divyesh P. Viththani , Ashok B. Joshi , Tapobroto Bhanja , Pankaj S. Joshi

We study the effects of a scalar condensate on a class of 2+1 dimensional non- Fermi liquids by introducing fermionic probes in the corresponding asymptotically AdS4 black hole backgrounds. For the range of parameters and couplings we…

High Energy Physics - Theory · Physics 2011-08-05 Pallab Basu , Jianyang He , Anindya Mukherjee , Moshe Rozali , Hsien-Hang Shieh

Total vacuum energy of some quantized fields in conical space with additional boundary conditions is calculated. These conditions are imposed on a cylindrical surface which is coaxial with the symmetry axis of conical space. The explicit…

High Energy Physics - Theory · Physics 2011-08-22 V. V. Nesterenko , I. G. Pirozhenko

We consider a modified version of four-dimensional electrodynamics, which has a photonic Chern-Simons-like term with spacelike background vector in the action. Light propagation in curved spacetime backgrounds is discussed using the…

High Energy Physics - Theory · Physics 2008-12-18 E. Kant , F. R. Klinkhamer

After reviewing the meaning of various equivalence principles and the structure of electrodynamics, we give a fairly detailed account of the construction of the light cone and a core metric from the equivalence principle for the photon (no…

General Relativity and Quantum Cosmology · Physics 2016-03-08 Wei-Tou Ni

We study the no reflection condition for a planar boundary between vacuum and an isotropic chiral medium. In general chiral media, elliptically polarized waves incident at a particular angle satisfy the no reflection condition. When the…

Optics · Physics 2009-11-13 Y. Tamayama , T. Nakanishi , K. Sugiyama , M. Kitano

It is proposed how to impose a general type of ''noncommutativity'' within classical mechanics from first principles. Formulation is performed in completely alternative way, i.e. without any resort to fuzzy and/or star product philosophy,…

High Energy Physics - Theory · Physics 2008-12-19 Denis Kochan

Temporal coherence is a fundamental property of macroscopic quantum systems, such as lasers in optics and Bose-Einstein condensates in atomic gases and it is a crucial issue for interferometry applications with light or matter waves.…

Quantum Gases · Physics 2015-05-13 Alice Sinatra , Yvan Castin , Emilia Witkowska

This paper investigates the influence of non-commutative geometry on various aspects of neutrino behavior in curved spacetime. Adopting a Schwarzschild-like black hole solution with Lorentzian mass deformation induced by non-commutativity,…

General Relativity and Quantum Cosmology · Physics 2025-04-08 A. A. Araújo Filho , N. Heidari , Yuxuan Shi

As illustrated by Schrodingers cat, there are often several macroscopically different versions of reality simultaneously existing in the wave function. On the face of it, this would seem to imply that an observer could perceive a…

Quantum Physics · Physics 2015-11-18 Casey Blood

A generally covariant four-dimensional representation of Maxwell's electrodynamics in a generic material medium can be achieved straightforwardly in the metric-free formulation of electromagnetism. In this setup, the electromagnetic…

General Relativity and Quantum Cosmology · Physics 2014-04-01 Yakov Itin