cosmology of f(t) gravity and k-essence重力和k-essence宇宙学的f(t).pdfVIP

Entropy 2012, 14, 1627-1651; doi:10.3390/ OPEN ACCESS entropy ISSN 1099-4300 /journal/entropy Article Cosmology of Gravity and k-Essence Ratbay Myrzakulov Eurasian International Center for Theoretical Physics, Department of General and Theoretical Physics, Eurasian National University, Astana 010008, Kazakhstan; E-Mails: rmyrzakulov@; rmyrzakulov@ Received: 20 July 2012; in revised form: 17 August 2012 / Accepted: 21 August 2012 / Published: 4 September 2012 Abstract: This a brief review on gravity and its relation with k-essence. Modified teleparallel gravity theory with the torsion scalar has recently gained a lot of attention as a possible explanation of dark energy. We perform a thorough reconstruction analysis on the so-called models, where is some general function of the torsion term, and deduce the required conditions for the equivalence between of models with pure kinetic k-essence models. We present a new class of models of -gravity and k-essence. Keywords: gravity; k-essence; cosmology; dark energy 1. Introduction Recent astrophysical data imply that the current expansion of the universe is accelerating [ 1]. There exist different candidates for this acceleration phase. The simplest one is the introduction of the Cosmological Constant in the framework of General Relativity (CDM model), namely an exotic form of energy (the dark energy) whose Equation of State (EoS) parameter is equal to minus one and dynamically remains near this value, but in principle quintessence/pha