Recently, a Hamilton-Jacobi method beyond semiclassical approximation in black hole physics was developed by Banerjee and Majhi [29]. In this paper, we generalize their analysis of black holes to the case of Friedmann-Robertson-Walker (FRW) universe. It is shown that all the higher order quantum corrections in the single particle action are proportional to the usual semiclassical contribution. ...

We use the single-mode coherent and squeezed number state formalism analyze nature of a massive homogeneous scalar field minimally coupled to gravity in framework semiclassical Friedmann-Robertson-Walker (FRW) universe. have obtained an estimate leading solution Einstein equation for FRW universe which shows scale factor $$t^{2/3}$$ power-law expansion. The mechanism particle production quantum...

Phase transitions in the early universe are prime settings for the production of primordial black holes, since they can break the relatively quiescent homogeneity and isotropy of Friedmann–Robertson–Walker (FRW) cosmologies. These epochs of “symmetry breaking,” moreover, can affect the subsequent development of spacetime by changing the evolution of some FRW parameters, including the present ag...

We study the thermodynamic properties of Friedmann-Robertson-Walker (FRW) universe in brane world scenario, concentrating on Randall-Sundrum II model. From first law thermodynamics for FRW universe, we find that work density W can be identified with pressure P. construct equation state P=P(V,T) which does not show P-V phase transition. further Joule-Thompson expansion and derive coefficient, ha...

Surface brightness data can distinguish between a Friedman-Robertson-Walker expanding universe and a nonexpanding universe. For surface brightness measured in AB magnitudes per angular area, all FRW models, regardless of cosmological parameters, predict that surface brightness declines with redshift as (z+1), while any non-expanding model predicts that surface brightness is constant with distan...

The Cardassian universe is a proposed modification to the Friedmann Robertson Walker equation in which the universe is flat, matter dominated, and accelerating. Here we generalize the original Cardassian proposal to include additional variants on the FRW equation; specific examples are presented. In the ordinary FRW equation, the right hand side is a linear function of the energy density, H2 ∼ ...