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Related papers: Electrodynamics with a Future Conformal Horizon

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We consider a spacetime singularity at $t = 0$ arising in a Kasner-type metric that solves the gravitational equations modified by quantum effects of a conformal field theory (CFT). The resulting constraints can be solved efficiently when…

High Energy Physics - Theory · Physics 2026-02-13 Sergey N. Solodukhin

Spacetime singularities have been discovered which are physically much weaker than those predicted by the classical singularity theorems. Geodesics evolve through them and they only display infinities in the derivatives of their curvature…

General Relativity and Quantum Cosmology · Physics 2015-12-09 John D. Barrow , Alexander A. H. Graham

Astrophysical observations provide a picture of the universe as a 4-dim homogeneous and isotropic flat space-time dominated by an unknown form of dark energy. To achieve such a cosmology one has to consider in the early universe an…

Astrophysics · Physics 2009-11-10 F. Canfora , A. Troisi

Action-at-a-distance electrodynamics - alternative approach to field theory - can be extended to cosmological models using conformal symmetry. An advantage of this is that the origin of arrow of time in electromagnetism can be attributed to…

General Relativity and Quantum Cosmology · Physics 2014-11-07 Kaustubh Sudhir Deshpande

An approach is presented to resolve key paradoxes in black hole physics through the application of complex Riemannian spacetime. We extend the Schwarzschild metric into the complex domain, employing contour integration techniques to remove…

General Relativity and Quantum Cosmology · Physics 2025-07-14 J. W. Moffat

An alternative interpretation of the conformal transformations of the metric is discussed according to which the latter can be viewed as a mapping among Riemannian and Weyl-integrable spaces. A novel aspect of the conformal transformation's…

General Relativity and Quantum Cosmology · Physics 2013-01-29 Israel Quiros , Ricardo Garcia-Salcedo , Jose Edgar Madriz Aguilar , Tonatiuh Matos

Spectral singularities such as exceptional points invoke specific physical effects. The present paper focuses upon the time dependent solutions of the Schr\"odinger equation. In a simple model it is demonstrated that - depending on initial…

Quantum Physics · Physics 2015-05-20 WD Heiss

An axisymmetric space-localized solution of nonlinear electrodynamics is considered as massive charged particle with spin and magnetic moment. The appropriate solution for nonlinear electrodynamics with ring singularity is investigated. In…

Mathematical Physics · Physics 2012-12-18 Alexander A. Chernitskii

We construct a piecewise model that gives a physical viable realization of finite-time future singularity for a spatially flat Friedmann-Robertson-Walker universe within the interacting dark matter--dark energy framework, with the latter…

General Relativity and Quantum Cosmology · Physics 2017-03-14 Mauricio Cataldo , Luis P. Chimento , Martín G. Richarte

This paper is devoted to study the gravitational charged perfect fluid collapse in the Friedmann universe models with cosmological constant. For this purpose, we assume that the electromagnetic field is so weak that it does not introduce…

General Relativity and Quantum Cosmology · Physics 2015-05-18 M. Sharif , G. Abbas

Solutions of the Friedmann-Lemaitre cosmological equations of general relativity have been found with finite-time singularities that are everywhere regular, have regular Hubble expansion rate, and obey the strong-energy conditions but…

General Relativity and Quantum Cosmology · Physics 2016-11-15 John D. Barrow , S. Cotsakis , A. Tsokaros

We investigate various dark energy models by taking into account the thermal effects induced from Hawking radiation on the apparent horizon of the Universe, for example near a finite-time future singularity. If the dark energy density…

General Relativity and Quantum Cosmology · Physics 2021-02-17 Artyom V. Astashenok , Sergei D. Odintsov , Vasilis K. Oikonomou

We study the effects of inhomogeneities on the evolution of the Universe, by considering a range of cosmological models with discretized matter content. This is done using exact and fully relativistic methods that exploit the symmetries in…

General Relativity and Quantum Cosmology · Physics 2015-06-17 Timothy Clifton , Daniele Gregoris , Kjell Rosquist , Reza Tavakol

In the present paper a geometrization of electrodynamics is proposed which makes use of a generalization of Riemannian geometry considered already by Einstein and Cartan in the 20ies. Cartan's differential forms description of a…

General Relativity and Quantum Cosmology · Physics 2008-02-03 Alexander Unzicker

A violation of the distance-duality relation is directly linked with a temporal variation of the electromagnetic fine-structure constant. We consider a number of well-studied $f(T)$ gravity models and we revise the theoretical prediction of…

Cosmology and Nongalactic Astrophysics · Physics 2020-12-09 Jackson Levi Said , Jurgen Mifsud , David Parkinson , Emmanuel N. Saridakis , Joseph Sultana , Kristian Zarb Adami

A framework is suggested in which the energy integrals of the Friedmann cosmology are identified as genuine time-independent physical characteristics for both vacuum and non-vacuum forms of cosmic energy. The integrals are found to be…

Astrophysics · Physics 2009-11-06 Arthur D. Chernin

We consider perturbative modifications of the Friedmann equations in terms of energy density corresponding to modified theories of gravity proposed as an alternative route to comply with the observed accelerated expansion of the universe.…

General Relativity and Quantum Cosmology · Physics 2015-05-13 L. Fernández-Jambrina , R. Lazkoz

Exotic forms of wave control have been emerging by engineering matter in space and time. In this framework, temporal photonic interfaces, i.e., abrupt changes in the electromagnetic properties of a material, have been shown to induce…

We study the effects of the time evolution of the matter-gravity coupling on the luminosity distance, showing it can provide a natural explanation to the apparent Hubble tension. The gravitational coupling evolution induces a modification…

General Relativity and Quantum Cosmology · Physics 2025-09-03 Antonio Enea Romano

This paper considers a new and deeply challenging face of the problem of time in the context of cosmology drawing on the work of Thiemann (2006, 2007). Thiemann argues for a radical response to the cosmic problem of time that requires us to…

General Relativity and Quantum Cosmology · Physics 2025-05-09 Nicola Bamonti , Karim P. Y. Thébault