A Cosmological Model With Fermionic Field

Abstract

In this work, a cosmological model inspired by string/M-theory with fermionic field is taken into consideration. Here it is investigated whether the introduction of a non-Dirac fermionic field — characterized by an interaction term — affects the cosmological evolution. The self-interaction potential is considered as a combination of the scalar and pseudoscalar invariants. It is observed that the fermionic field under consideration behaves like an inflation field for the early universe and later on, as a dark energy field. The late time acceleration becomes more prominent by the addition of the interaction term. There is a slight decrease for the inflation peak as well as for the energy density. We see that the addition of higher-order terms to the fermionic part of Lagrangian does not significantly change either the inflation or the late time acceleration behavior.

Modified Chaplygin gas and solvable F-essence cosmologies

“…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.…”

Cosmological analysis of scalar field models in f(R, T) gravity

“…The right plots of 3 and 4 satisfyφ To analyze a big-rip free model, the key point is that if the EoS parameter rapidly approaches −1 and the Hubble rate tends to be constant (asymptotically de Sitter universe), then it is possible to have a model in which the time required for a singularity is infinite, i.e., the singularity effectively does not occur [44]. The occurrence of a maximum potential of a phantom scalar field is another evident issue as regards avoiding this singularity [45]. The graphical behavior of the EoS parameter represents that ω eff rapidly approaches −1 and the Hubble rate is decreasing but the potential is not maximum.…”

A Terrestrial Search for Dark Contents of the Vacuum, Such as Dark Energy, Using Atom Interferometry

“…Thus some theorists speculate that there is a common source of the two and the ratio has a deeper explanation. We will not discuss such ideas here, but refer the reader to reference [31].…”