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Related papers: Coupled tachyonic dark energy: a dynamical analysi…

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Usually considered highly speculative, tachyons can be treated via straightforward Einsteinian dynamics. Kinetic theory and thermodynamics for a gas of ``dark'' tachyons are readily constructed. Such a gas exhibits density and pressure…

General Relativity and Quantum Cosmology · Physics 2022-06-15 James M. Starke , Ian H. Redmount

We apply the formalism of dynamical system analysis to investigate the evolution of interacting dark energy scenarios at the background and perturbation levels in a unified way. Since the resulting dynamical system contains the extra…

General Relativity and Quantum Cosmology · Physics 2022-02-10 Wompherdeiki Khyllep , Jibitesh Dutta , Spyros Basilakos , Emmanuel N. Saridakis

In this paper we consider a correspondence between the holographic dark energy density and tachyon energy density in FRW universe. Then we reconstruct the potential and the dynamics of the tachyon field which describe tachyon cosmology.

High Energy Physics - Theory · Physics 2008-11-26 M R Setare

Recent observations from the DESI survey have reignited the debate on the true nature of dark energy, challenging the standard model of cosmology. The results suggest a preference for dynamical dark energy rather than a constant. Several…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-28 Ramanpreet Singh , Athul CN , H. K. Jassal

A cosmology is considered driven by a stress-energy tensor consisting of a perfect fluid, an inhomogeneous pressure term (which we call a ``tachyonic dust'' for reasons which will become apparent) and a cosmological constant. The…

General Relativity and Quantum Cosmology · Physics 2008-11-26 A. Das , A. DeBenedictis

Motivated by recent work of one of us [1], we generalize this work to agegraphic tachyon models of dark energy with entropy correction terms arising from loop quantum gravity. We establish a connection between the entropy-corrected…

General Physics · Physics 2011-01-25 Mubasher Jamil , Ahmad Sheykhi

Recently it has been argued that a possible source for the dark energy may arise due to the contribution to the vacuum energy of the QCD ghost in a time-dependent background. In this paper we establish a connection between interacting ghost…

High Energy Physics - Theory · Physics 2012-04-10 A. Sheykhi , M. Sadegh Movahed , E. Ebrahimi

The main goal of this work is to propose a generalized model of interacting dark energy which allows for the kinetic term of a scalar field to couple to the matter species a priori in the action. We derive the modified field equations, and…

General Relativity and Quantum Cosmology · Physics 2019-04-01 Bruno J. Barros

Scalar-field dark energy models like tachyon are often regarded as an effective description of an underlying theory of dark energy. In this Letter, we implement the interacting agegraphic dark energy models with tachyon field. We…

High Energy Physics - Theory · Physics 2015-05-13 A. Sheykhi

A cosmological model of dark energy interacting with dark matter and another general component of the universe is investigated. We found general constraints on these models imposing an accelerated expansion. The same is also studied in the…

High Energy Physics - Phenomenology · Physics 2008-11-26 Norman Cruz , Samuel Lepe , Francisco Pena

The coincidence problems and other dynamical features of dark energy are studied in cosmological models with variable cosmological parameters and in models with the composite dark energy. It is found that many of the problems usually…

Astrophysics · Physics 2008-11-26 Javier Grande , Joan Sola , Hrvoje Stefancic

The coupling between the dark components provides a new approach to mitigate the coincidence problem of cosmological standard model. In this paper, dark energy is treated as a fluid with a constant equation of state, whose coupling with…

Cosmology and Nongalactic Astrophysics · Physics 2014-08-18 Weiqiang Yang , Lixin Xu

In this paper, we consider Bianchi type-V space-time and study a cosmological model of dark energy based on Tachyon scalar field. We assumed three different kinds of matter without possibility of interaction with scalar dark energy.…

General Relativity and Quantum Cosmology · Physics 2015-01-13 J. Sadeghi , H. Farahani

We investigate a multi-field model of dark energy in this paper. We develop a model of dark energy with two multiple scalar fields, one we consider, is a multifield tachyon and the other is multi-field phantom tachyon scalars. We make an…

General Relativity and Quantum Cosmology · Physics 2020-12-29 Muhammad Zahid Mughal , Iftikhar Ahmad

We use linear perturbation theory to study perturbations in dynamical dark energy models. We compare quintessence and tachyonic dark energy models with identical background evolution. We write the corresponding equations for different…

Cosmology and Nongalactic Astrophysics · Physics 2021-11-17 Manvendra Pratap Rajvanshi , Avinash Singh , H. K. Jassal , J. S. Bagla

We perform a detailed dynamical analysis of the teleparallel dark energy scenario, which is based on the teleparallel equivalent of General Relativity, in which one adds a canonical scalar field, allowing also for a nonminimal coupling with…

General Relativity and Quantum Cosmology · Physics 2012-07-09 Chen Xu , Emmanuel N. Saridakis , Genly Leon

We outline a dynamical dark energy scenario whose signatures may be simultaneously tested by astronomical observations and laboratory experiments. The dark energy is a field with slightly sub-gravitational couplings to matter, a logarithmic…

Astrophysics · Physics 2009-06-23 Nemanja Kaloper

We derive two field theory models of interacting dark energy, one in which dark energy is associated with the quintessence and another in which it is associated with the tachyon. In both, instead of choosing arbitrarily the potential of…

General Relativity and Quantum Cosmology · Physics 2020-07-10 Sandro M. R. Micheletti

We present a detailed study of cosmological effects of homogeneous tachyon matter coexisting with non-relativistic matter and radiation, concentrating on the inverse square potential and the exponential potential for the tachyonic scalar…

Astrophysics · Physics 2011-05-05 J. S. Bagla , H. K. Jassal , T. Padmanabhan

Cosmology with a three-form field interacting with cold dark matter is considered. In particular, the mass of the dark matter particles is assumed to depend upon the amplitude of the three-form field invariant. In comparison to coupled…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Tomi S. Koivisto , Nelson J. Nunes