We consider the thermodynamics of minimally coupled massive scalar field in 3+1 dimensional Taub-NUT background. The brick wall model of 't Hooft is used. When Schwarzschild like coordinates are used it is found that the usual radial brick wall cutoff parameter is required to regularize the solution. Free energy of the scalar field is obtained through explicit counting of states. It is found th...

We consider two quantum cosmological models with a massive scalar field: an ordinary Friedmann universe and a universe containing primordial black holes. For both models we discuss the complex solutions to the Euclidean Einstein equations. Using the probability measure obtained from the Hartle-Hawking no-boundary proposal, we find that the only unsuppressed black holes start at the Planck size ...

The results on chaos in FRW cosmology with a massive scalar field are extended to another scalar field potential. It is shown that for sufficiently steep potentials the chaos disappears. A simple and rather accurate analytical criterion for the chaos to disappear is given. On the contrary, for gently sloping potentials the transition to a strong chaotic regime can occur. Two examples, concernin...

Abstact We quantize the tachyon field in a static two dimensional dilaton gravity black hole background,and we calculate the Hawking radiation rate.We find that the thermal radiation flux,due to the tachyon field, is larger than the conformal matter one.We also find that massive scalar fields which do not couple to the dilaton,do not give any contribution to the thermal radiation, up to terms q...

A massive scalar field in a curved spacetime can propagate along the light cone, a causal pathology, which can, in principle, be eliminated only if the scalar couples conformally to the Ricci curvature of spacetime. This property mandates conformal coupling for the field driving inflation in the early universe. During slow-roll inflation, this coupling can cause super-acceleration and, as a sig...

By introducing the generalized uncertainty principle, we calculate the entropy of the bulk scalar field on the Randall-Sundrum brane background without any cutoff. We obtain the entropy of the massive scalar field proportional to the horizon area. Here, we observe that the mass contribution to the entropy exists in contrast to all previous results of the usual black hole cases with the generali...