Complete cosmic scenario from inflation to late time acceleration: Nonequilibrium thermodynamics in the context of particle creation

Abstract

The paper deals with the mechanism of particle creation in the framework of irreversible thermodynamics. The second order non-equilibrium thermodynamical prescription of Israel and Stewart has been presented with particle creation rate, treated as the dissipative effect.In the background of a flat FRW model, we assume the non-equilibrium thermodynamical process to be isentropic so that the entropy per particle does not change and consequently the dissipative pressure can be expressed linearly in terms of the particle creation rate. Here the dissipative pressure behaves as a dynamical variable having a non-linear inhomogeneous evolution equation and the entropy flow vector satisfies the second law of thermodynamics.Further, using the Friedmann equations and by proper choice of the particle creation rate as a function of the Hubble parameter, it is possible to show (separately) a transition from the inflationary phase to the radiation era and also from matter dominated era to late time acceleration. Also, in analogy to analytic continuation, it is possible to show a continuous cosmic evolution from inflation to late time acceleration by adjusting the parameters. It is found that in the de Sitter phase, the comoving entropy increases exponentially with time, keeping entropy per particle unchanged. Subsequently, the above cosmological scenarios has been described from field theoretic point of view by introducing a scalar field having self interacting potential. Finally, we make an attempt to show the cosmological phenomenon of particle creation as Hawking radiation, particularly during the inflationary era.

Dynamical analysis of an interacting dark energy model in the framework of a particle creation mechanism

“…Here, the independent variable is chosen as the lapse time N = ln a, which is called the e-folding number and the particle production rate Γ as a function of the Hubble parameter [66,70] (Γ has dimensions (time) −1 ) is chosen as above Γ = Γ 0 H (Γ 0 is a constant). The value of the parameter Γ 0 is assumed to be nonnegative as the creation of particles are only considered in this study.…”

Particle production and universal thermodynamics

“…In other words, the cosmic substratum is not a conventional dissipative fluid, rather a perfect fluid with varying particle number. This statement can clearly be understood for the simple case of adiabatic (i.e., isentropic) particle production as follows [34,35]Starting from the Gibb's relation [i.e., from Eq. (2)]…”

“…Now using the Einstein field equations (6), the condition for adiabatic process [i.e., Eq. (10)] can be stated as [34,35] …”

Does particle creation mechanism favour formation of black hole or naked singularity?

“…It is found [27,29] that by proper choice of the particle creation rate (as function of Hubble parameter) the late time accelerated expansion can be described in the context of Einstein's general relativistic theory (GRT) without introduction of any exotic matter (dark energy). Also recently [26] it is shown that the above models not only describe the late phase of the evolution but also describe the entire cosmic evolution since inflation to CDM model. The present work is also related to the particle creation mechanism but in the context of well known astrophysical problem namely the final fate of a massive collapsing star.…”

“…In recent years, a lot of works [26][27][28][29][30][31][32] have been done in cosmology in the perspective of non-equilibrium thermodynamics within the framework of particle creation mechanism. The main motivation of these works is to explain the well known observational evidence that our universe is going through an accelerating phase since recent past.…”