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Related papers: Cosmology with Varying Constants

200 papers

A numerical coincidence relating the values of the cosmological, gravitational and electromagnetic fine structure constants is presented and discussed in relation to the apparent anthropic fine-tuning of these three fundamental constants of…

General Relativity and Quantum Cosmology · Physics 2015-10-26 Laurence Eaves

We take another look at the equations behind the description of light bending in a Universe with a cosmological constant. We show that even within the impact parameter entering into the photon's differential equation, and which is defined…

General Relativity and Quantum Cosmology · Physics 2015-08-17 Fayçal Hammad

Cosmological discoveries over the past century have completely changed our picture of our place in the universe. New observations have a realistic chance of probing nature on heretofore unimaginable scales, and as a result are changing the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Lawrence M. Krauss

It is possible that there may be differences in the fundamental physical parameters from one side of the observed universe to the other. I show that the cosmological constant is likely to be the most sensitive of the physical parameters to…

High Energy Physics - Phenomenology · Physics 2009-11-07 John F. Donoghue

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

In addressing the cosmological constant problem, we propose that the discrepancy between the theoretical and observed values can be ascribed to the inherent uncertainty in the spacetime metric. Mach's principle, which posits that mass…

General Relativity and Quantum Cosmology · Physics 2023-09-06 Ahmed Farag Ali , Nader Inan

The value of the cosmological constant is one of the major puzzles of modern cosmology: it is tiny but nonzero. Sorkin predicted, from the Causet approach to quantum gravity, that the cosmological constant has quantum fluctuations. The…

General Relativity and Quantum Cosmology · Physics 2009-06-19 Rohit Katti , Joseph Samuel , Supurna Sinha

We will look for an implementation of new symmetries in the space-time structure and their cosmological implications. This search will allow us to find a unified vision for electrodynamics and gravitation. We will attempt to develop a…

General Physics · Physics 2011-11-10 Claudio Nassif

We review the status of bouncing cosmologies as alternatives to cosmological inflation for providing a description of the very early universe, and a source for the cosmological perturbations which are observed today. We focus on the…

High Energy Physics - Theory · Physics 2017-03-08 Robert Brandenberger , Patrick Peter

Astrophysics and cosmology can be used to test the standard model of particle physics under conditions and over distance and time scales not accessible to laboratory experiments. Most of the astrophysical observations are in good agreement…

High Energy Physics - Phenomenology · Physics 2016-09-01 Arnon Dar

The theory of cosmological perturbations has become a cornerstone of modern quantitative cosmology since it is the framework which provides the link between the models of the very early Universe such as the inflationary Universe scenario…

High Energy Physics - Theory · Physics 2017-08-23 Robert H. Brandenberger

This letter explores how a reinterpretation of the generalized uncertainty principle as an effective variation of Planck's constant provides a physical explanation for a number of fundamental quantities and couplings. In this context, a…

General Physics · Physics 2024-09-02 Ahmed Farag Ali , Jonas Mureika , Elias C. Vagenas , Ibrahim Elmashad

Last couple of decades have been the golden age for cosmology. High quality data confirmed the broad paradigm of standard cosmology but have thrusted upon us a preposterous composition for the universe which defies any simple explanation,…

General Relativity and Quantum Cosmology · Physics 2016-11-23 T. Padmanabhan

Astrophysical indications that the fine structure constant has undergone a small time variation during the cosmological evolution are discussed within the framework of the standard model of the electroweak and strong interactions and of…

High Energy Physics - Phenomenology · Physics 2009-11-07 Xavier Calmet , Harald Fritzsch

Recent observations of Type 1a supernovae indicating an accelerating universe have once more drawn attention to the possible existence, at the present epoch, of a small positive Lambda-term (cosmological constant). In this paper we review…

Astrophysics · Physics 2009-10-31 Varun Sahni , Alexei Starobinsky

Modern fundamental physics poses new questions for philosophy, which, as it seems to us, have not yet received appropriate attention from philosophers of science. This paper formulates a number of such questions in order to present them to…

General Physics · Physics 2025-04-29 A. Panov

The author proposed in his previous papers in 2001 that the problem of the cosmological constant could be resolved and its calculated value agrees excellently with the observations by assuming that the space-time itself, as the phase of…

General Physics · Physics 2007-05-23 H. M. Mok

Modern cosmology has created a tight link between particle physics / field theory and a wealth of new observational data on the structure of the Universe. These lecture notes focus on some of the most important aspects concerning the…

High Energy Physics - Phenomenology · Physics 2007-05-23 Robert H. Brandenberger

There are now two cosmological constant problems: (i) why the vacuum energy is so small and (ii) why it comes to dominate at about the epoch of galaxy formation. Anthropic selection appears to be the only approach that can naturally resolve…

High Energy Physics - Theory · Physics 2007-06-20 Alexander Vilenkin

We show how the scalar field, a candidate of quintessence, in a proposed model of the scalar-tensor theories of gravity provides a way to understand a small but nonzero cosmological constant as indicated by recent observations. A particular…

General Relativity and Quantum Cosmology · Physics 2009-09-25 Yasunori Fujii