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Related papers: Varying constants quantum cosmology

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We consider gravity theory with varying speed of light and varying gravitational constant. Both constants are represented by non-minimally coupled scalar fields. We examine the cosmological evolution in the near curvature singularity…

General Relativity and Quantum Cosmology · Physics 2015-04-17 Adam Balcerzak

We review recent work on the possibility of a varying speed of light (VSL). We start by discussing the physical meaning of a varying $c$, dispelling the myth that the constancy of $c$ is a matter of logical consistency. We then summarize…

Astrophysics · Physics 2008-11-26 Joao Magueijo

This article is dedicated to cosmologies with variable speed of light (VSL) - models, which one can consider as a particular case of models of a modified gravitation. In quantum cosmology the closed universe can spontaneously nucleate out…

High Energy Physics - Theory · Physics 2011-05-17 Artyom V. Yurov , Valerian A. Yurov

We build a minimal extension of General Relativity in which Newton's gravitational coupling, $G$, the speed of light, $c$, and the cosmological constant, $\Lambda$, are spacetime variables. This is done while satisfying the contracted…

General Relativity and Quantum Cosmology · Physics 2017-04-27 Guilherme Franzmann

We have investigated a cosmological model with variable speed of light (c), gravitational constant (G) and cosmological constant (Lambda). The model is shown to solve the horizon, flatness and monopole problems of the early universe. We…

Astrophysics · Physics 2007-05-23 Arbab I. Arbab

Observations indicate that most of the universal matter are invisible and the gravitational constant $G(t)$ maybe depends on the time. A theory of the variational $G$ (VG) is explored in this paper, with naturally producing the useful dark…

Cosmology and Nongalactic Astrophysics · Physics 2015-10-13 Jianbo Lu , Yanfeng Xu , Yabo Wu

We develop a new model for the Universe based on two key assumptions: first, the inertial energy of the Universe is a constant, and second, the total energy of a particle, the inertial plus the gravitational potential energy produced by the…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Hossein Shojaie , Mehrdad Farhoudi

Cosmological perturbation theory provides a fundamental framework for analyzing the evolution of density fluctuations and gravitational potentials in the Universe. It plays a crucial role in understanding large-scale structure formation and…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-14 Seokcheon Lee

We review recent progress in the study of varying constants and attempts to explain the observed values of the fundamental physical constants. We describe the variation of $G$ in Newtonian and relativistic scalar-tensor gravity theories. We…

General Relativity and Quantum Cosmology · Physics 2009-09-25 John D. Barrow

We tackle the problem of the accelerating universe by reconsidering the most general form of the metric when the speed of light is allowed to evolve with time in a homogeneous and isotropic universe. A new varying speed of light (VSL) model…

General Relativity and Quantum Cosmology · Physics 2007-07-17 Corrado Appignani

In quantum cosmology the closed universe can spontaneously nucleate out of the state with no classical space and time. The semiclassical tunneling nucleation probability can be estimated as $\emph{P}\sim\exp(-\alpha^2/\Lambda)$ where…

High Energy Physics - Theory · Physics 2007-05-23 A. V. Yurov , V. A. Yurov

Even though there have been the various varying speed of light (VSL) cosmology models, they remain out of the mainstream because of their possible violation of physics laws built into fundamental physics. In order to be the VSL as a viable…

Cosmology and Nongalactic Astrophysics · Physics 2024-07-03 Seokcheon Lee

We analyse a generalisation of general relativity that incorporates a cosmic time-variation of the velocity of light in vacuum, $c,$ and the Newtonian gravitation 'constant', $G,$ proposed by Albrecht and Maguejo. We find exact solutions…

Astrophysics · Physics 2009-10-31 John D. Barrow

We assume the anisotropic model of the Universe in the framework of varying speed of light $c$ and varying gravitational constant $G$ theories and study different types of singularities. For the singularity models, we write the scale…

General Relativity and Quantum Cosmology · Physics 2021-05-07 Ujjal Debnath , Soumak Nag

We address the question how to adapt cosmological constant $\Lambda$ for description of a vacuum dark energy density jumping from the big initial value to the small today value suggested by observations. We find such a possibility in the…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Irina Dymnikova , Michael Fil'chenkov

Under the assumption that the cosmological constant vanishes in the true ground state with lowest possible energy density, we argue that the observed small but finite vacuum-like energy density can be explained if we consider a theory with…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Jun'ichi Yokoyama

In quantum cosmology the closed universe can spontaneously nucleate out of the state with no classical space and time. For the universe filled with a vacuum of constant energy density the semiclassical tunneling nucleation probability can…

High Energy Physics - Theory · Physics 2016-09-06 A. V. Yurov , V. A. Yurov

Fundamental constants are a cornerstone of our physical laws. Any constant varying in space and/or time would reflect the existence of an almost massless field that couples to matter. This will induce a violation of the universality of free…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Jean-Philippe Uzan

We derive a redshift drift formula within the framework of varying speed of light (VSL) theory using the specific ansatz for the variability of $c(t) = c_0 a^n(t)$. We show that negative values of the parameter $n$, which correspond to…

Cosmology and Nongalactic Astrophysics · Physics 2016-04-26 Adam Balcerzak , Mariusz P. Dabrowski

We develop the Brans-Dicke theory of gravity in the context of varying constants of Nature. Using the unimodular formalism of General Relativity, we create a platform to provide physical relational times giving the evolution of physical…

General Relativity and Quantum Cosmology · Physics 2023-12-08 Paolo Massimo Bassani
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