169 citations · 180 across the 2 of their papers we have counts for
5 papers
Trans-Planckian Physics from a Nonlinear Dispersion Relation
S. E. Joras, G. Marozzi
We study a particular nonlinear dispersion relation -- a series expansion in the physical wavenumber -- for modeling first-order corrections in the equation of mot…
Dark Interactions and Cosmological Fine-Tuning
Miguel Quartin, Mauricio O. Calvao, Sergio E. Joras +2
Cosmological models involving an interaction between dark matter and dark energy have been proposed in order to solve the so-called coincidence problem. Different forms of coupling…
Entropy perturbations in quartessence Chaplygin models
R. R. R. Reis, I. Waga, M. O. Calvao +1
We show that entropy perturbations can eliminate instabilities and oscillations, in the mass power spectrum of the quartessence Chaplygin models. Our results enlarge the current pa…
Noise and Dissipation During Preheating
Sergio E. Joras, Rudnei O. Ramos
We study the consequences of noise and dissipation for parametric resonance during preheating. The effective equations of motion for the inflaton and the radiation field are obtain…
Uniform semiclassical approximation in quantum statistical mechanics
C. A. A. de Carvalho, R. M. Cavalcanti, E. S. Fraga +1
We present a simple method to deal with caustics in the semiclassical approximation to the partition function of a one-dimensional quantum system. The procedure, which makes use of…