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For a certain type of modified dispersion relations, the vacuum quantum state for very short wavelength cosmological perturbations is scale-invariant and it has been suggested that this may be the source of the scale-invariance observed in…

General Relativity and Quantum Cosmology · Physics 2018-02-28 Stefano Bianco , Victor Nicolai Friedhoff , Edward Wilson-Ewing

In this communication, we consider a wide class of extensions to General Relativity that break explicitly the Einstein Equivalence Principle by introducing a multiplicative coupling between a scalar field and the electromagnetic Lagrangian.…

General Relativity and Quantum Cosmology · Physics 2015-05-06 A. Hees , O. Minazzoli , J. Larena

We use Hubble parameter versus redshift data from Stern, et al(2010) and Gazta\~{n}aga, et al (2009) to place constraints on model parameters of constant and time-evolving dark energy cosmological models. These constraints are consistent…

Cosmology and Nongalactic Astrophysics · Physics 2013-07-12 Yun Chen , Bharat Ratra

Asymptotic properties of electromagnetic waves are studied within the context of Friedmann-Robertson-Walker (FRW) cosmology. Electromagnetic fields are considered as small perturbations on the background spacetime and Maxwell's equations…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Nader Haghighipour

In the recent work~\cite{Wang:2021p2}, the author proposed the expanded Maxwell's equations for moving charged media system, which seems subtle. Considering a very short time, we can approximately define the inertial frame of reference. If…

Classical Physics · Physics 2022-02-15 Chuang Li , Junle Pei , Tianjun Li

We investigate the evolution of gravitational waves through discontinuous evolution (transition) of the Hubble expansion rate $H(z)$ at a sudden cosmological singularity, which may be due to a transition of the value of the gravitational…

Cosmology and Nongalactic Astrophysics · Physics 2023-07-04 Evangelos Achilleas Paraskevas , Leandros Perivolaropoulos

General Relativity receives quantum corrections relevant at cosmological distance scales from the conformal scalar degrees of freedom required by the trace anomaly of the quantum stress tensor in curved space. In the theory including the…

General Relativity and Quantum Cosmology · Physics 2012-09-25 Emil Mottola

In general relativity, Maxwell's equations are embedded in curved spacetime through the minimal prescription, but this could change if strong-gravity modifications are present. We show that with a nonminimal coupling between gravity and a…

General Relativity and Quantum Cosmology · Physics 2019-02-27 Lorenzo Annulli , Vitor Cardoso , Leonardo Gualtieri

The change of the electromagnetic field in a particular place due to the event of a change in the motion of a charged particle can occur only after the light signal from the event can reach this place. Naive calculations of the…

Classical Physics · Physics 2009-11-07 Amnon Kislev , Lev Vaidman

In this lecture I address the issue of possible large distance modification of gravity and its observational consequences. Although, for the illustrative purposes we focus on a particular simple generally-covariant example, our conclusions…

High Energy Physics - Theory · Physics 2007-05-23 Gia Dvali

We consider the instabilities of field perturbations around a homogeneous background color-electric and/or -magnetic field in SU(2) pure gauge theory. We investigate a number of distinct cases of background magnetic and electric fields, and…

High Energy Physics - Phenomenology · Physics 2024-03-06 Divyarani C. Geetha , Anders Tranberg

The cosmological redshifts z in the frequencies of spectral lines from distant galaxies as compared with their values observed in terrestrial laboratories, which are due to the scale factor a(t), frequently are interpret as a…

General Physics · Physics 2011-12-07 Branislav Vlahovic

A great number of macroquantum laws connecting gravity and electromagnetism if found empirically. To describe them the model of anisotropic gravitational field is proposed. This field is build as a superposition of planes and force lines…

General Physics · Physics 2007-05-23 Alexander M. Ilyanok

It is shown that for Robertson-Walker models with flat or closed space sections, all of the cosmological spectral shift can be attributed to the non-flat connection (and thus indirectly to space-time curvature). For Robertson-Walker models…

General Physics · Physics 2013-03-29 Dag Østvang

In an undulant universe, cosmic expansion is characterized by alternating periods of acceleration and deceleration. We examine cosmologies in which the dark-energy equation of state varies periodically with the number of e-foldings of the…

Astrophysics · Physics 2009-11-11 Gabriela Barenboim , Olga Mena Requejo , Chris Quigg

If the fine structure constant $\alpha =e^2/(\hbar c)$ were to change, then a number of interpretations would be possible, attributing this change either to variations in the electron charge, the dielectric constant of the vacuum, the speed…

Astrophysics · Physics 2009-10-31 John D. Barrow , Joao Magueijo

We extend the duality symmetry between the electric and the magnetic fields to the case in which an additional axion-like term is present, and we derive the set of Maxwell's equations that preserves this symmetry. This new set of equations…

Classical Physics · Physics 2022-06-14 Luca Visinelli

Observers have demonstrated that it is now feasible to measure the cosmic microwave background (CMB) temperature at high redshifts. We explore the possible constraints on cosmology which might ultimately be derived from such measurements.…

Astrophysics · Physics 2009-11-07 John M. LoSecco , Grant J. Mathews , Yun Wang

Very high energy physics needs a coherent description of the four fundamental forces. Non-commutative geometry is a promising mathematical framework which already allowed to unify the general relativity and the standard model, at the…

Mathematical Physics · Physics 2009-12-07 Fabien Vignes-Tourneret

Using Bridge Theory to describe the electromagnetic interactions occurring between high energy pairs of particles, we predict an anomalous self-gravitational red-shift in the frequency of the EM source produced during the interaction. The…

General Physics · Physics 2009-02-05 Massimo Auci
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