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Related papers: Conformally Coupled Tachyonic Dark Energy

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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

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

In this work we study the cosmological evolution of a dark energy model with two scalar fields, i.e. the tachyon and the phantom tachyon. This model enables the equation of state $w$ to change from $w>-1$ to $w<-1$ in the evolution of the…

Astrophysics · Physics 2009-12-04 Shang-Gang Shi , Yun-Song Piao , Cong-Feng Qiao

We show that all cosmological models with an accelerated stationary global attractor reduce asymptotically to a dark energy field with an exponential potential coupled linearly to a perfect fluid dark matter. In such models the abundance of…

Astrophysics · Physics 2009-11-07 Domenico Tocchini-Valentini , Luca Amendola

We investigate tachyon dynamics with an inverse power-law potential $V(\phi) \propto \phi^{-\alpha}$. We find global attractors of the dynamics leading to a dust behaviour for $\alpha > 2$ and to an accelerating universe for $0 < \alpha \le…

Astrophysics · Physics 2011-07-18 L. Raul W. Abramo , Fabio Finelli

Dark matter interacts gravitationally, but it presumably interacts weakly through other channels, especially with respect to regular luminous matter. We look at different ways in which dark matter may couple to other fields. We briefly…

General Physics · Physics 2018-09-27 Kevin J. Ludwick

The fact that the energy densities of dark energy and matter are similar currently, known as the coincidence problem, is one of the main unsolved problems of cosmology. We present here a model in which a spatial curvature of the universe…

Astrophysics · Physics 2009-11-13 Urbano Franca

In this paper we consider Tachyonic scalar field as dark energy with interaction between components in the case of variable $G$ and $\Lambda$. We assume a flat Universe with specific form of scale factor and study cosmological parameters…

General Relativity and Quantum Cosmology · Physics 2015-02-03 J. Sadeghi , M. Khurshudyan , M. Hakobyan , H. Farahani

We present the conformal freeze-in (COFI) scenario for dark matter production. At high energies, the dark sector is described by a gauge theory flowing towards a Banks-Zaks fixed point, coupled to the standard model via a non-renormalizable…

High Energy Physics - Phenomenology · Physics 2020-06-24 Sungwoo Hong , Gowri Kurup , Maxim Perelstein

The introduction of an interaction for dark energy to the standard cosmology offers a potential solution to the cosmic coincidence problem. We examine the conditions on the dark energy density that must be satisfied for this scenario to be…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Micheal S. Berger , Hamed Shojaei

Scalar-field dark energy models for tachyon fields are often regarded as an effective description of an underlying theory of dark energy. In this paper, we propose the agegraphic dark energy model in tachyon cosmology by interaction between…

General Physics · Physics 2015-06-05 H. Farajollahi , A. Ravanpak , G. F. Fadakar

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

In Cosmology, when dissipative effects are minimal, the energy content of the Universe can be effectively described as a sum of perfect fluids. Perfect fluid descriptions ensure thermal equilibrium since they equilibrate immediately.…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-16 Pulkit Bansal , Joseph P Johnson , S. Shankaranarayanan

Rolling tachyon field models are among the candidates suggested as explanations for the recent acceleration of the Universe. In these models the field is expected to interact with gauge fields and lead to variations of the fine-structure…

Cosmology and Nongalactic Astrophysics · Physics 2016-06-28 C. J. A. P. Martins , F. M. O. Moucherek

The so called `cosmic coincidence' problem seems to suggest a coupling between dark energy and dark matter. A possibility could be given by dark matter particles with masses depending exponentially on the scalar field associated to dark…

High Energy Physics - Phenomenology · Physics 2007-05-23 Massimo Pietroni

We investigate several varying-mass dark-matter particle models in the framework of phantom cosmology. We examine whether there exist late-time cosmological solutions, corresponding to an accelerating universe and possessing dark energy and…

General Relativity and Quantum Cosmology · Physics 2014-11-18 Genly Leon , Emmanuel N. Saridakis

We investigate an interacting dark energy model which allows for the kinetic term of the scalar field to couple to dark matter via a power-law interaction. The model is characterised by scaling solutions at early times, which are of high…

Cosmology and Nongalactic Astrophysics · Physics 2022-12-06 Elsa M. Teixeira , Bruno J. Barros , Vasco M. C. Ferreira , Noemi Frusciante

Early dark energy has emerged as one of the more promising approaches to address the Hubble tension - the statistically significant disparity between measurements of the Hubble constant made using data from different epochs in cosmic…

Cosmology and Nongalactic Astrophysics · Physics 2022-10-03 Mark Trodden

We discuss some cosmological consequences of a general model of coupled quintessence in which the phenomenological coupling between the cold dark matter and dark energy is a function of the cosmic scale factor $\epsilon(a)$. This class of…

Cosmology and Nongalactic Astrophysics · Physics 2010-12-23 F. E. M. Costa

An interaction between dark matter and dark energy is usually introduced by a phenomenological modification of the matter conservation equations, while the Einstein equations are left unchanged. Starting from some general and fundamental…

General Relativity and Quantum Cosmology · Physics 2015-09-16 Nicola Tamanini