English
Related papers

Related papers: Dark spinors with torsion in cosmology

200 papers

We study the interaction between dark matter and dark energy, with dark energy described by a scalar field having a double exponential effective potential. We discover conditions under which such a scalar field driven solution is a late…

General Relativity and Quantum Cosmology · Physics 2015-08-06 Vartika Gupta , Rakesh Kabir , Amitabha Mukherjee , Daksh Lohiya

We perform a full investigation on dynamics of a new dark energy model in which the four-derivative of a non-canonical scalar field (tachyon) is non-minimally coupled to the vector torsion. Our analysis is done in the framework of…

General Relativity and Quantum Cosmology · Physics 2015-06-23 Behnaz Fazlpour , Ali Banijamali

We confront Einstein-Cartan's theory with the Hubble diagram. An affirmative answer to the question in the title is compatible with today's supernovae data.

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Andre Tilquin , Thomas Schucker

A new model of accelerating expansion of the universe is presented. A de Sitter solution in vacuum and a exact solution with the dust mater source are obtained. A new explanation of the acceleration of the cosmic expansion is given. In is…

General Physics · Physics 2013-01-16 G. Y. Chee

Modern astrophysical and cosmological models are plagued with two severe theoretical difficulties, namely, the dark energy and the dark matter problems. Relative to the former, high-precision observational data have confirmed with startling…

General Relativity and Quantum Cosmology · Physics 2015-05-05 Francisco S. N. Lobo

Physics invites the idea that space contains energy whose gravitational effect approximates that of Einstein's cosmological constant, Lambda; nowadays the concept is termed dark energy or quintessence. Physics also suggests the dark energy…

Astrophysics · Physics 2008-11-26 P. J. E. Peebles , Bharat Ratra

An exact, axially symmetric solution to the Einstein-Klein-Gordon field equations is employed to model the dark matter in spiral galaxies. The extended rotation curves from a previous analysis are used to fit the model and a very good…

Astrophysics · Physics 2007-05-23 F. S. Guzman , T. Matos , H. Villegas-Brena

This paper deals with the cancellation mechanism, which identifies the energy density of space-time expansion in an empty universe with the zero-point energy density and avoids the scale discrepancy with the observed energy density…

General Physics · Physics 2018-06-12 Christian Henke

Dark matter is obtained from a scalar field coupled conformally to gravitation; the scalar being a relict of Dirac's gauge function. This conformally coupled dark matter includes a gas of very light ($m\approx 2.25\times 10^{-34} eV$)…

General Relativity and Quantum Cosmology · Physics 2009-10-28 Mark Israelit

We consider the cosmology of a thick codimension 1 brane. We obtain the matching conditions leading to the cosmological evolution equations and show that when one includes matter with a pressure component along the extra dimension in the…

High Energy Physics - Theory · Physics 2009-11-11 Ignacio Navarro , Jose Santiago

A formalism for the appearance of dark energy in the matter dominated era, leading to a persistent de Sitter expansion at the late time is proposed. Our framework is a hybrid quintessence model with a non-minimal coupling to the Ricci…

General Relativity and Quantum Cosmology · Physics 2018-11-29 H. Mohseni Sadjadi

Fluctuations on de Sitter solution of Einstein-Cartan field equations are obtained in terms of the matter density primordial density fluctuations and spin-torsion density and matter density fluctuations obtained from COBE data. Einstein-de…

General Relativity and Quantum Cosmology · Physics 2007-05-23 L. C. Garcia de Andrade

We study the phase space dynamics of cosmological models in the theoretical formulations of non-minimal metric-torsion couplings with a scalar field, and investigate in particular the critical points which yield stable solutions exhibiting…

General Relativity and Quantum Cosmology · Physics 2017-08-18 Arshdeep Singh Bhatia , Sourav Sur

We investigate the late-time evolution of the Universe within a cosmological model in which dark matter and dark energy are identified with two interacting scalar fields. Using methods of qualitative analysis of dynamical systems, we…

General Relativity and Quantum Cosmology · Physics 2021-06-14 Paulo M. Sá

A Newtonian-like theory inspired by the Brans-Dicke gravitational Lagrangian has been recently proposed in Ref. arXiv:2009.04434(v4). We propose here a new variant of this theory such that the usual Newtonian second law is preserved. The…

General Relativity and Quantum Cosmology · Physics 2025-07-14 Felipe S. Escórcio , Júlio C. Fabris , Júnior D. Toniato , Hermano Velten

Cosmologies based on General Relativity encompassing an anti-symmetric connection (torsion) can display nice desirable features as the absence of the initial singularity and the possibility of inflation in the early stage of the universe.…

General Relativity and Quantum Cosmology · Physics 2018-12-12 Sergio Bravo Medina , Marek Nowakowski , Davide Batic

A central theme in cosmology is the perplexing fact that the Universe is undergoing an accelerating expansion. The latter, one of the most important and challenging current problems in cosmology, represents a new imbalance in the governing…

General Relativity and Quantum Cosmology · Physics 2011-09-28 Francisco S. N. Lobo

I describe a tensor-vector-scalar theory that reconciles the galaxy scale success of modified Newtonian dynamics (MOND) with the cosmological scale evidence for CDM. The theory provides a cosmological basis for MOND in the sense that the…

Astrophysics · Physics 2009-11-10 R. H. Sanders

In this paper, the dynamical attractor and heteroclinic orbit have been employed to make the late-time behaviors of the model insensitive to the initial condition and thus alleviate the fine-tuning problem in the torsion cosmology. The…

General Relativity and Quantum Cosmology · Physics 2010-04-22 Xin-zhou Li , Chang-bo Sun , Ping Xi

A spinning fluid embedded in a space section flat Friedmann model is used to compute the cosmological density perturbation of the model.The spinning fluid obeys the Einstein-Cartan field equations while the Friedmann embedded model is…

Astrophysics · Physics 2007-05-23 L. C. Garcia de Andrade
‹ Prev 1 8 9 10 Next ›