English
Related papers

Related papers: Dark spinor model with torsion and cosmology

200 papers

We solve one of the open problems in Einstein-Cartan theory, namely we find a natural matter source whose spin angular momentum tensor is compatible with the cosmological principle. We analyze the resulting evolution equations and find that…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Christian G. Boehmer , James Burnett

We introduce and carefully define an entire class of field theories based on non-standard spinors. Their dominant interaction is via the gravitational field which makes them naturally dark; we refer to them as Dark Spinors. We provide a…

High Energy Physics - Theory · Physics 2012-12-11 Christian G. Boehmer , James Burnett , David F. Mota , Douglas J. Shaw

We propose a new dark energy model for solving the cosmological fine-tuning and coincidence problems. A default assumption is that the fine-tuning problem disappears if we do not interpret dark energy as vacuum energy. The key idea to…

Cosmology and Nongalactic Astrophysics · Physics 2020-03-27 S. X. Tián

In this letter, we study the late-time evolution of a torsion cosmology only with the spin-$0^+$ mode. We find three kinds of analytical solutions with a constant affine scalar curvature. In the first case, it is not physical because the…

General Relativity and Quantum Cosmology · Physics 2019-08-17 Xi-chen Ao , Xin-zhou Li , Ping Xi

A cosmological approach based on considering a cosmic background with non-zero torsion is shown in order to give an option of explaining a possible phantom evolution, not ruled out according to the current observational data. We revise some…

General Relativity and Quantum Cosmology · Physics 2020-10-28 Fernando Izaurieta , Samuel Lepe

The torsion is shown to be vitally important in the explanation of the evolution of the universe in a large class of gravitational theories containing quadratic terms of curvature and torsion. The cosmological solutions with homogeneous and…

General Relativity and Quantum Cosmology · Physics 2011-07-19 Chao-Guang Huang , Hai-Qing Zhang , Han-Ying Guo

A cosmological theory that predicts a late-time accelerated attractor with a constant dark matter to dark energy ratio can be said to solve the Coincidence Problem. Such cosmologies are naturally generated in the context of non-standard…

Astrophysics · Physics 2009-11-11 James L. Crooks , Paul H. Frampton

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

Recently, the so-called Elko spinor field has been proposed to be a candidate of dark energy. It is a non-standard spinor and has unusual properties. When the Elko spinor field is used in cosmology, its unusual properties could bring some…

General Relativity and Quantum Cosmology · Physics 2010-12-21 Hao Wei

In this paper, we explore the cosmological implications of interacting dark energy model in a torsion based gravity namely $f(T)$. Assuming dark energy interacts with dark matter and radiation components, we examine the stability of this…

General Physics · Physics 2012-03-27 Mubasher Jamil , D. Momeni , Ratbay Myrzakulov

Investigations of the dynamic modes of the Poincare gauge theory of gravity found only two good propagating torsion modes; they are effectively a scalar and a pseudoscalar. Cosmology affords a natural situation where one might see…

General Relativity and Quantum Cosmology · Physics 2008-12-18 Kun-Feng Shie , James M. Nester , Hwei-Jang Yo

The paper deals with cosmological solutions describing different phases of the Universe for the homogeneous and isotropic FLRW model of the Universe with torsion. Normally, torsion field is not suitable for maximally symmetric space time…

General Relativity and Quantum Cosmology · Physics 2020-10-30 Akash Bose , Subenoy Chakraborty

We investigate the cosmology of massive spinor electrodynamics when torsion is non-vanishing. A non-minimal interaction is introduced between the torsion and the vector field and the coupling constant between them plays an important role in…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Edward J. Kim , Seyen Kouwn , Phillial Oh , Chan-Gyung Park

We propose a cosmological model that makes a significant step toward solving the coincidence problem of the near similarity at the present of the dark energy and dark matter components. Our cosmology has the following properties: a) among…

Astrophysics · Physics 2008-11-26 Luca Amendola , Domenico Tocchini-Valentini

A formulation of cosmology driven by fermions $\psi $ is studied. Assumption that the expectation value of the fermion bilinear is non-zero simplifies the homogeneous solution of the Dirac equations and connects the spinor field with the…

General Relativity and Quantum Cosmology · Physics 2023-06-09 David Benisty

We investigate the coupled system of gravity and a scalar with exponential potential. The energy momentum tensor of the scalar field induces a time-dependent cosmological ``constant''. This adjusts itself dynamically to become in the…

High Energy Physics - Theory · Physics 2011-05-23 Christoph Wetterich

Observational evidence indicating that the expansion of the universe is accelerating has surprised cosmologists in recent years. Cosmological models have sought to explain this acceleration by incorporating `dark energy', of which the…

Astrophysics · Physics 2010-03-26 Luke Barnes , Matthew J. Francis , Geraint F. Lewis , Eric V. Linder

The Standard Model of particle physics and the $\Lambda$CDM model of cosmology provide an incomplete description of our Universe. Both models face challenges, including explaining the nature of dark matter, the origin of the Universe's…

High Energy Physics - Phenomenology · Physics 2025-12-24 Giacomo Ferrante

The breakdown of conformal symmetry in a conformally invariant scalar-tensor gravitational model is revisited in the cosmological context. Although the old scenario of conformal symmetry breaking in cosmology containing scalar field has…

General Relativity and Quantum Cosmology · Physics 2013-08-13 F. Darabi

We study Dirac spinors in Bianchi type-I cosmological models, within the framework of torsional $f(R)$-gravity. We find four types of results: the resulting dynamic behavior of the universe depends on the particular choice of function…

General Relativity and Quantum Cosmology · Physics 2011-11-14 Stefano Vignolo , Luca Fabbri , Roberto Cianci
‹ Prev 1 2 3 10 Next ›