Interacting Tachyon Dark Energy Model in Gauss-Bonnet Cosmology
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Interacting Tachyon Dark Energy Model in Gauss-Bonnet Cosmology V. Fayaz · F. Felegary · H. Hossienkhani
Received: 28 May 2012 / Accepted: 4 September 2012 © Springer Science+Business Media, LLC 2012
Abstract We investigate the tachyon scalar filed model of dark energy in the framework of Gauss-Bonnet cosmology. We consider a spatially non-flat universe containing interacting tachyon dark energy with pressureless dark matter. We obtain the equation of state and deceleration parameters. We also reconstruct the potential and the dynamics for the tachyon scalar field model, which describe accelerated expansion of the universe. Keywords Tachyon scalar filed · Dark energy · Dark matter
1 Introduction Nowadays it is strongly believed that the universe is undergoing an accelerated expansion. These observations are those which are obtained by type Ia Supernova (SNeIa) [1, 2], Large Scale Structure (LSS) [3] and Cosmos Microwave Background (CMB) [4]. This acceleration is triggered by more than 70 % of dark energy (DE) which is an exotic energy with negative pressure, but the nature of DE is still unknown. Among different candidates for probing the nature of DE, the most obvious theoretical candidate of DE is the cosmological constant, Λ, which has an equation of state (EoS) parameter ω = −1 [5, 6]. There are different alternative theories for the dynamical DE scenario which have been proposed by people to interpret the accelerating universe. The models of dark energy including quintessence [7, 8], phantom (ghost) field [9–11], K-essence [12, 13], Tachyon field [14–23], dilatonic ghost condensate [24–26], quintom [27, 28], braneworld [29–32]. V. Fayaz () · F. Felegary · H. Hossienkhani Department of Physics, Hamedan Branch, Islamic Azad University, Hamedan, Iran e-mail: [email protected] F. Felegary e-mail: [email protected] H. Hossienkhani e-mail: [email protected]
Int J Theor Phys
The scalar field models (such as tachyon, K-essence and dilaton) are often regarded as an effective description of an underlying theory of DE. The scalar field models can also alleviate the fine tuning and coincidence problems [33]. Scalar fields naturally arise in particle physics including supersymmetric field theories and string/M theory. Therefore, scalar field is expected to reveal the dynamical mechanism and the nature of DE. However, although fundamental theories such as string/M theory do provide a number of possible candidates for scalar fields, they do not uniquely predict its potential V (φ). Therefore it becomes meaningful to reconstruct V (φ) from some DE models possessing some significant features of the quantum gravity theory, such as holographic and agegraphic DE models [34–37]. In the present work, we study the tachyon scalar filed model of DE in the framework of Gauss-Bonnet gravity [29–32]. To do this, we consider a spatially non-flat FriedmannRobertson-Walker (FRW) universe filled with the interacting tachyon DE and pressureless dark matter (DM). We obtain the EoS and deceleration parameters f
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