arXiv subjects

G. C. Marques

Publications and source records attributed to G. C. Marques.

3 recordsLinked to original sources

arXiv2005

Mechanocaloric and Thermomechanical Effects in Bose-Einstein Condensed Systems

In this paper we extend previous hydrodynamic equations, governing the motion of Bose-Einstein-condensed fluids, to include temperature effects. This allows us to analyze some differences between a normal fluid and a Bose-Einstein-condensed one. We show that, in close analogy with superfluid He-4, a Bose-Einstein-condensed fluid exhibits the mechanocaloric and thermomechanical effects. In our approach we can explain both effects without using the hypothesis that the Bose-Einstein-condensed fluid has zero entropy. Such ideas could be investigated in existing experiments.

cond-mat.stat-mech↗

arXiv1993

On the Evaluation of Thermal Corrections to False Vacuum Decay Rates

We examine the computation of the nucleation barrier used in the expression for false vacuum decay rates in finite temperature field theory. By a detailed analysis of the determinantal prefactor, we show that the correct bounce solution used in the computation of the nucleation barrier should not include loop corrections coming from the scalar field undergoing decay. Temperature corrections to the bounce appear from loop contributions from other fields coupled to the scalar field. We compute the nucleation barrier for a model of scalar fields coupled to fermions, and compare our results to the expression commonly used in the literature. We find that, for large enough self-couplings, the inclusion of scalar loops in the expression of the nucleation barrier leads to an underestimate of the decay rate in the neighborhood of the critical temperature.

hep-ph↗

arXiv1992

Quantum Corrections to Nucleation Rates

In this paper we show how to compute in a consistent way nucleation rates in field theory at finite temperatures, with metastable vacuum. Using the semiclassical approach in field theory at finite temperature we show that the prefactor term can be calculated explicitly (in the thin-wall approximation) and that the same provides exponential finite temperature quamtum corrections to nucleation rates, when fluctuations around the bubble field configuration are considered.

hep-ph↗