Fermions as sources of accelerated regimes in cosmology

Abstract

In this work it is investigated if fermionic sources could be responsible for accelerated periods during the evolution of a universe where a matter field would answer for the decelerated period. The self-interaction potential of the fermionic field is considered as a function of the scalar and pseudoscalar invariants. Irreversible processes of energy transfer between the matter and gravitational fields are also considered. It is shown that the fermionic field could behave like an inflaton field in the early universe and as dark energy for an old universe.PACS numbers: 98.80.-k, 98.80.Cq

Dark Energy

“…There are attempts to generalize the scalar field dark energy model to spinors [280,281,282,283], vectors [284,285], and p-form fields [286,287]. Here we shall briefly mention the approaches of spinors.…”

Anisotropic cosmological models with spinor and scalar fields and viscous fluid in presence of a Λ term: Qualitative solutions

“…10,7,4,1], volume scale τ(t) [Figs. 11,8,5,2] and phase portrait in ν, H, ε space [Figs.12,9,6,3], for α = 4,…”

“…In order to answer to these questions a number of theories has been proposed by cosmologists. It has been shown that the introduction of a nonlinear spinor field or an interacting spinor and scalar fields depending on some special choice of nonlinearity can give rise to singularity free solutions in one hand [1,2,3,4], on the other hand they may exploited to explain the late time acceleration [5,6].…”

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

“…The Dirac equation was investigated for massless spinor fields in curved space-time more than 50 years ago [6]. Spinor fields can be used to describe the primordial inflation [7] and current expansion [8]. However, the exact solutions in the presence of the spinor field is difficult to build (for example, see [9]).…”