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Finsler geometry is a natural and fundamental generalization of Riemann geometry. The Finsler structure depends on both coordinates and velocities. We present the arrival time delay of astroparticles subject to Lorentz violation in the…

General Relativity and Quantum Cosmology · Physics 2022-06-28 Jie Zhu , Bo-Qiang Ma

Optical quasar spectra can be used to trace variations of the fine-structure constant alpha. Controversial results that have been published in last years suggest that in addition to to wavelength calibration problems systematic errors might…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Nils Prause , Dieter Reimers

Further investigation of data on quasars, especially in the ultraviolet band, yields an amazingly coherent narrative which we present in this paper. Quasars are characterised by strong continuum emission and redshifted emission and…

Astrophysics of Galaxies · Physics 2017-12-07 Nimisha G. Kantharia

We revisit the {\it origin of structures problem} of standard Friedmann-Robertson-Walker cosmology to point out an unjustified approximation in the prevalent analysis. We follow common procedures in statistical mechanics to revise the issue…

High Energy Physics - Theory · Physics 2007-05-23 David H. Oaknin

The Cosmological Principle, which states that the Universe is homogeneous and isotropic (when averaged on large scales), is the foundational assumption of Friedmann-Lemaitre-Robertson-Walker (FLRW) cosmologies such as the current standard…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-15 Nathan Secrest , Sebastian von Hausegger , Mohamed Rameez , Roya Mohayaee , Subir Sarkar

We demonstrate that recent measurements of Cosmic Microwave Background temperature and polarization anisotropy made by the ACBAR, QUAD and BICEP experiments substantially improve the cosmological constraints on possible variations of the…

Cosmology and Nongalactic Astrophysics · Physics 2010-10-28 Eloisa Menegoni , Silvia Galli , James Bartlett , Carlos J. A. P. Martins , Alessandro Melchiorri

Development of fundamental physics relies on the constancy of various fundamental quantities such as the fine structure constant. Detecting or constraining the possible time variations of these fundamental physical quantities is an…

Astrophysics · Physics 2009-11-10 H. Chand , R. Srianand , P. Petitjean , B. Aracil

The cosmological principle is fundamental to the standard cosmological model. It assumes that the Universe is homogeneous and isotropic on very large scales. As the basic assumption, it must stand the test of various observations. In this…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-13 J. P. Hu , Y. Y. Wang , J. Hu , F. Y. Wang

We work with a class of scalar extended theory of gravity that can drive the present cosmic acceleration as well as accommodate a mild cosmic variation of the fine structure constant $\alpha$. The motivation comes from a vintage theory…

General Relativity and Quantum Cosmology · Physics 2022-04-20 Soumya Chakrabarti

We study the evolution of the fine-structure constant, $\alpha$, induced by non-linear density perturbations in the context of the simplest class of quintessence models with a non-minimal coupling to the electromagnetic field, in which the…

Astrophysics · Physics 2009-11-13 P. P. Avelino , C. J. A. P. Martins , J. Menezes , C. Santos

QSO absorption spectra provide an extremely useful probe of possible cosmological variation in various physical constants. Comparison of H I 21cm absorption with corresponding molecular (rotational) absorption spectra allows us to constrain…

Astrophysics · Physics 2009-08-18 M. T. Murphy , J. K. Webb , V. V. Flambaum , M. J. Drinkwater , F. Combes , T. Wiklind

We present a class of models in which the coupling of the photon to an ultralight scalar field that has a time-dependent vacuum expectation value causes the fine structure constant to oscillate in time. The scalar field is assumed to…

High Energy Physics - Phenomenology · Physics 2022-09-07 Dawid Brzeminski , Zackaria Chacko , Abhish Dev , Anson Hook

We analyze the consistency of different astronomical data of the variation in the fine-structure constant obtained with KECK and VLT. We tested the consistency using the Student test and confidence intervals. We splited the data sets in to…

Cosmology and Nongalactic Astrophysics · Physics 2013-08-27 Lucila Kraiselburd , Susana J. Landau , Claudio Simeone

We consider the problem of the evolution of the fine structure coefficient alpha under the assumption that the scalar field coupling to the Maxwell term satisfies the condition mt>>1 for coherent dark matter oscillations. In this case we…

Astrophysics · Physics 2009-11-10 M. G. Barnett , R. Dick , K. E. Wunderle

We study some properties of a recently proposed local Lorentz Violating Finsler geometry, the so-called Bipartite space. This anisotropic structure deforms the causal null surface to an elliptic cone and provides an anisotropy to the…

High Energy Physics - Theory · Physics 2014-03-07 J. E. G. Silva , C. A. S. Almeida

Exploring the possibility that fundamental constants of Nature might vary temporally or spatially constitutes one of the key science drivers for the European Southern Observatory's ESPRESSO spectrograph on the VLT and for the HIRES…

Cosmology and Nongalactic Astrophysics · Physics 2021-04-21 Chung-Chi Lee , John K. Webb , R. F. Carswell , Dinko Milaković

Webb et al. presented preliminary evidence for a time-varying fine-structure constant. We show Teller's formula for this variation to be ruled out within the Einstein-de Sitter universe, however, it is compatible with cosmologies which…

Astrophysics · Physics 2007-05-23 R. W. Kuhne

Finsler geometry is a natural generalization of pseudo-Riemannian geometry. It can be motivated e.g. by a modified version of the Ehlers-Pirani-Schild axiomatic approach to space-time theory. Also, some scenarios of quantum gravity suggest…

General Relativity and Quantum Cosmology · Physics 2015-06-23 Yakov Itin , Claus Lämmerzahl , Volker Perlick

We derive strong observational limits on any possible large-scale spatial variation in the values of physical 'constants' whose space-time evolution is driven by a scalar field. The limits are imposed by the isotropy of the microwave…

Astrophysics · Physics 2009-11-10 John D. Barrow

Within the framework of projective geometry, we investigate kinematics and symmetry in $(\alpha,\beta)$ spacetime-one special types of Finsler spacetime. The projectively flat $(\alpha,\beta)$ spacetime with constant flag curvature is…

General Relativity and Quantum Cosmology · Physics 2010-10-22 Xin Li , Zhe Chang