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Related papers: Nowadays cosmology with the Weyl-Dirac approach

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Gravity is attributed to the spacetime curvature in classical General Relativity (GR). But, other equivalent formulation or representations of GR, such as torsion or non-metricity have altered the perception. We consider the Weyl-type $f(Q,…

General Relativity and Quantum Cosmology · Physics 2021-10-20 Gaurav Gadbail , Simran Arora , P. K. Sahoo

We show that the Einstein-Cartan-Sciama-Kibble theory of gravity with torsion not only extends general relativity to account for the intrinsic spin of matter, but it may also eliminate major problems in gravitational physics and answer…

General Relativity and Quantum Cosmology · Physics 2016-10-25 Nikodem J. Poplawski

We discuss cosmological solutions for a diffeomorphism invariant gauge theory of the non-compact Lorentz group $SO(1,3)$. Besides the gauge bosons our model of pregeometry contains a vector field in the vector representation of $SO(1,3)$…

General Relativity and Quantum Cosmology · Physics 2021-12-01 C. Wetterich

Topological matter with Weyl points, such as superfluid 3He-A, provide an explicit example where there is a direct connection between the properly determined vacuum energy and the cosmological constant of the effective gravity emerging in…

General Relativity and Quantum Cosmology · Physics 2013-02-18 G. Jannes , G. E. Volovik

Rising to Mach, the problem of establishing the unity of the physical essence of the Universe on all space-time scales of its evolution is, apparently, one of the main problems in contemporary epistemology. The issues are primarily related…

General Physics · Physics 2019-02-13 Serge F. Timashev

Recent astrophysical observations indicate that the universe is composed of a large amount of dark energy (DE) responsible for an accelerated expansion of the universe, along with a sizeable amount of cold dark matter (CDM), responsible for…

A unique description of the Big Crunch-Big Bang transition is given at the classical gravity level, along with a complete set of homogeneous, isotropic, analytic solutions in scalar-tensor cosmology, with radiation and curvature. All…

High Energy Physics - Theory · Physics 2012-09-07 Itzhak Bars

We consider a hypothesis that the closed Universe was formed on the other side of the event horizon of a black hole existing in another universe. That black hole appears in the Universe as a boundary white hole, and its rest frame in…

General Relativity and Quantum Cosmology · Physics 2020-03-03 Nikodem J. Popławski

For two decades the hot big-bang model has been referred to as the standard cosmology -- and for good reason. For just as long cosmologists have known that there are fundamental questions that are not addressed by the standard cosmology and…

Astrophysics · Physics 2007-05-23 Michael S. Turner

Cosmic acceleration is widely believed to require either a source of negative pressure (i.e., dark energy), or a modification of gravity, which necessarily implies new degrees of freedom beyond those of Einstein gravity. In this paper we…

High Energy Physics - Theory · Physics 2017-06-28 Lasha Berezhiani , Justin Khoury , Junpu Wang

We introduce the hypothesis that the matter content of the universe can be a product of the decay of primordial vector bosons. The effect of the intensive cosmological creation of these primordial vector $W, ~Z $ bosons from the vacuum is…

High Energy Physics - Theory · Physics 2016-09-06 D. Blaschke , V. Pervushin , D. Proskurin , S. Vinitsky , A. Gusev

There is now strong evidence that the current energy density of the Universe is dominated by dark energy with an equation of state w<-1/3, which is causing accelerated expansion. The build-up of structure within such Universes is subject to…

Astrophysics · Physics 2008-11-26 Will J. Percival

General Relativistic Entropic Acceleration (GREA) theory provides a covariant formalism for out-of-equilibrium phenomena in GR, extending the Einstein equations with an entropic force that behaves like bulk viscosity with a negative…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-28 Juan Garcia-Bellido

The universe today, with structure such as stars, galaxies and black holes, seems to have evolved from a very homogeneous initial state. From this it appears as if the entropy of the universe is decreasing, in violation of the second law of…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Oystein Rudjord , Oyvind Gron

We show that the general theory of relativity can be formulated in the language of Weyl geometry. We develop the concept of Weyl frames and point out that the new mathematical formalism may lead to different pictures of the same…

General Relativity and Quantum Cosmology · Physics 2015-06-03 C. Romero , J. B. Fonseca-Neto , M. L. Pucheu

This paper explores the dark sector (dark matter and dark energy) from the perspective of Weyl geometric scalar tensor theory (integrable Weyl geometry). In order to account for the galactic dynamics successfully modelled by MOND ("modified…

General Relativity and Quantum Cosmology · Physics 2022-06-14 Erhard Scholz

The presence of dark energy in the Universe is inferred directly and indirectly from a large body of observational evidence. The simplest and most theoretically appealing possibility is the vacuum energy density (cosmological constant).…

Astrophysics · Physics 2008-11-26 J. S. Alcaniz

The accelerating expansion of the Universe poses a major challenge to our understanding of fundamental physics. One promising avenue is to modify general relativity and obtain a new description of the gravitational force. Because…

General Relativity and Quantum Cosmology · Physics 2015-08-28 Adam R. Solomon

A new vision of the beginning and expansion of our universe has produced a solution to the vacuum energy problem (also known as "cosmological constant problem"). A new dynamic of cellular spaces and a discrete time has space being produced…

Astrophysics · Physics 2007-05-23 Charles B. Leffert

We provide a simple analytical solution of the Friedmann equations for a universe made of stiff matter, dust matter, and dark energy. A stiff matter era is present in the cosmological model of Zel'dovich (1972) where the primordial universe…

General Relativity and Quantum Cosmology · Physics 2015-12-02 Pierre-Henri Chavanis