A Cosmological Model With Fermionic Field and Gauss–bonnet Term

Abstract

In this work, a cosmological model inspired by string theory with Gauss–Bonnet term coupled to the fermionic field is taken into consideration. The self-interaction potential is considered as a combination of the scalar and pseudoscalar invariants. Here the cosmological contribution of the coupling of Gauss–Bonnet term with a non-Dirac fermionic field — characterized by an interaction term[Formula: see text] — is investigated. It is observed that the new type of coupling plays a significant role in the accelerating behavior of the universe. Specifically, in addition to the late time acceleration for the universe, [Formula: see text] produces an early decelerating behavior. The behavior of the equation-of-state parameter (w) is such that it guarantees the stability of the theory.

Modified Chaplygin gas and solvable F-essence cosmologies

“…The fermionic fields are treated here as classically commuting fields (see e.g. Ribas et al 2005;Cai and Wang 2008;Wang et al 2010;Rakhi et al 2010;Chimento et al 2008;Saha 2004;Vakili and Sepangi 2008;Wei 2011;Dereli et al 2001;Balantekin and Dereli 2007;Armendariz-Picon and Greene 2003). What we mean by a classical fermionic field is a set of four complex-valued space-time functions that transform according to the spinor representation of the Lorenz group.…”

“…However, in the recent years several approaches were made to explain the accelerated expansion by taking fermionic fields as the gravitational sources of energy (see e.g. Ribas et al 2005;Samojeden et al 2009Samojeden et al , 2010Tsyba et al 2011;Yerzhanov et al 2011;Ribas and Kremer 2010;Cai and Wang 2008;Wang et al 2010;Ribas et al 2008;Rakhi et al 2009Rakhi et al , 2010Chimento et al 2008;Anischenko et al 2009;Saha 2001Saha , 2004Saha , 2006aSaha , 2006bSaha and Shikin 1997;Vakili and Sepangi 2008;Wei 2011;Dereli et al 2001;Balantekin and Dereli 2007;ArmendarizPicon and Greene 2003). In particular, it was shown that the fermionic field plays very important role in: (i) isotropization of initially anisotropic spacetime; (ii) formation of singularity free cosmological solutions; (iii) explaining latetime acceleration.…”

Accelerating and decelerating cosmology from spinor and scalar fields non-minimally coupled with f(R) gravity

“…A significant number of attempts have been made to construct the cosmological models with a spinor field for description of dark energy, where a non-canonical kinetic term was considered, such as k-inflation and k-essence models [10]. In [11], the properties of one of the foregoing models with self-interacting spinor with the noncanonical kinetic term were studied.…”

Dirac fields, torsion and Barbero-Immirzi parameter in cosmology

“…[1][2][3][4][5][6][7][8][9][10]). There are many papers considering not only the classical aspects of the theory, but also quantum ones.…”