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Related papers: Dynamics of Generalized Tachyon Field in Teleparal…

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We study general properties of attractors for tachyonic potential chameleon scalar-field model which possess cosmological scaling solutions. An analytic formulation is given to obtain fixed points with a discussion on their stability. The…

General Relativity and Quantum Cosmology · Physics 2015-05-28 H. Farajollahi , A. Salehi , F. Tayebi , A. Ravanpak

We study inflation, perturbations, non-gaussinity and late-time cosmological dynamics of a tachyon field both minimally and non-minimally coupled to gravity. By analyzing the parameters space of the model, the viability of the model in…

General Relativity and Quantum Cosmology · Physics 2015-06-16 Kourosh Nozari , Narges Rshidi

We study the general properties of attractors in a cosmological model with tachyonic potential and a scalar field non-minimally coupled to matter. A general analytic formulation is given to derive fixed points with a discussion on their…

General Relativity and Quantum Cosmology · Physics 2011-07-08 H. Farajollahi , A. Salehi

We study the dynamics of the scalar tensor cosmological model in the presence of tachyon field. In an alternative approach, in two exponential and power law form of the scalar field functions in the model, field equations are solved by…

General Relativity and Quantum Cosmology · Physics 2011-11-22 H. Farajollahi , A. Salehi , A. Shahabi

In this paper, we have outlined the development of an autonomous dynamical system within a general scalar-tensor gravity framework. This framework encompasses the overall structure of the non-minimally coupled scalar field functions for…

General Relativity and Quantum Cosmology · Physics 2024-10-14 S. A. Kadam , L. K. Duchaniya , B. Mishra

This study explores the plausibility of an interacting tachyonic scalar, homogeneous in nature, as a promising candidate for dynamic dark energy, offering insights into the observed accelerated expansion of the universe. The…

General Relativity and Quantum Cosmology · Physics 2025-07-16 Tanisha Joshi , S. D Pathak

Teleparallel description of gravity theories where the gravity is mediated through the tetrad field and consequent torsion provide an alternative route to explain the late time cosmic speed up issue. Generalization of the teleparallel…

General Relativity and Quantum Cosmology · Physics 2025-01-10 S. K. Tripathy , Sasmita Pal , B. Mishra

We investigate the case of a homogeneous tachyon field coupled to gravity in a spatially flat Friedman-Robertson-Walker spacetime. Assuming the field evolution to be exponentially decaying with time we solve the field equations and show…

Astrophysics · Physics 2009-11-11 A. Das , Shashikant Gupta , Tarun Deep Saini , Sayan Kar

We investigate in detail the asymptotic properties of tachyon cosmology for a broad class of self-interaction potentials. The present approach relies in an appropriate re-definition of the tachyon field, which, in conjunction with a method…

General Relativity and Quantum Cosmology · Physics 2011-03-28 Israel Quiros , Tame Gonzalez , Dania Gonzalez , Yunelsy Napoles , Ricardo Garcia-Salcedo , Claudia Moreno

Combining the general relativity and the uncertainty relation in quantum mechanics, the energy density of quantum fluctuations of space-time can be viewed as dark energy. The so-called agegraphic dark energy model is just based on this…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-18 Jinglei Cui , Li Zhang , Jingfei Zhang , Xin Zhang

Motivated by the recent interest in cosmologies arising from energy density modifications to the Friedmann equation, we analyse the scaling behaviour for a broad class of these cosmologies comprised of scalar fields and background…

Astrophysics · Physics 2009-11-10 Edmund J. Copeland , Seung-Joo Lee , James E. Lidsey , Shuntaro Mizuno

We study a tachyon model with non-minimal derivative coupling to gravity in the Friedmann-Robertson-Walker flat cosmology. We propose the special re-definition of the tachyon field which allows us to represent tachyon field equation…

General Relativity and Quantum Cosmology · Physics 2012-09-13 V. K. Shchigolev , M. P. Rotova

We develop a technique for the reconstruction of the potential for a scalar field or a tachyon field, reproducing a given cosmological evolution in a closed and open isotropic cosmological models. Such potentials are explicitly written down…

General Relativity and Quantum Cosmology · Physics 2015-06-03 Alexander Y. Kamenshchik , Serena Manti

Aims. We investigated the gravitational effects of a scalar field within scalar-tensor gravity as an alternative to dark matter. Motivated by chameleon, symmetron and f(R)-gravity models, we studied a phenomenological scenario where the…

Cosmology and Nongalactic Astrophysics · Physics 2014-01-24 David F. Mota , Vincenzo Salzano , Salvatore Capozziello , Nicola R. Napolitano

We study the cosmological perturbations in teleparallel dark energy models in which there is a dynamical scalar field with a non-minimal coupling to gravity. We find that the propagating degrees of freedom are the same as in quintessence…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Chao-Qiang Geng , Yi-Peng Wu

We present and study a conformally coupled dark energy model, characterised by an interaction between a tachyon field $\phi$, with an inverse square potential $V (\phi)$, and the matter sector. A detailed analysis of the cosmological…

General Relativity and Quantum Cosmology · Physics 2019-09-06 Elsa M. Teixeira , Ana Nunes , Nelson J. Nunes

We study the correspondence between the interacting viscous ghost dark energy model with the tachyon, K-essence and dilaton scalar field models in the framework of Einstein gravity. We consider a spatially non-flat FRW universe filled with…

General Physics · Physics 2013-07-30 K. Karami , K. Fahimi

Using the "teleparallel" equivalent of General Relativity as the gravitational sector, which is based on torsion instead of curvature, we add a canonical scalar field, allowing for a nonminimal coupling with gravity. Although the minimal…

High Energy Physics - Theory · Physics 2015-05-30 Chao-Qiang Geng , Chung-Chi Lee , Emmanuel N. Saridakis , Yi-Peng Wu

We perform a detailed phase-space analysis of various phantom cosmological models, where the dark energy sector interacts with the dark matter one. We examine whether there exist late-time scaling attractors, corresponding to an…

General Relativity and Quantum Cosmology · Physics 2009-12-04 Xi-ming Chen , Yungui Gong , Emmanuel N. Saridakis

We study the cosmological evolution of a tachyon scalar field T with a Dirac-Born-Infeld type lagrangian and potential V(T) coupled to a canonically normalized scalar field \phi with an arbitrary interaction term B(T,\phi) in the presence…

High Energy Physics - Theory · Physics 2008-11-26 A. de la Macorra , U. Filobello