15 citations · 38 across the 5 of their papers we have counts for
10 papers
Primordial Universe with radiation and Bose-Einstein condensate
F. G. Alvarenga, L. G. Ferreira Filho, R. Fracalossi +5
In this work we derive a scenario {in which} the early universe consists of {radiation fluid} and Bose-Einstein condensate. The possibility of gravitational self-interaction due to…
Classical and quantum cosmology with two perfect fluids: stiff matter and radiation
F. G. Alvarenga, R. Fracalossi, R. C. Freitas +1
In this work the homogeneous and isotropic Universe of Friedmann-Robertson-Walker is studied in the presence of two fluids: stiff matter and radiation described by the Schutz's for…
The Kantowski-Sachs quantum model with stiff matter fluid
F. G. Alvarenga, R. Fracalossi, R. C. Freitas +1
In this paper we study the quantum cosmological Kantowski-Sachs model and solve the Wheeler-DeWitt equation in minisuperspace to obtain the wave function of the corresponding unive…
Non-linear clustering during the BEC dark matter phase transition
Rodolfo C. de Freitas, Hermano Velten
Spherical collapse of the Bose-Einstein Condensate (BEC) dark matter model is studied in the Thomas Fermi approximation. The evolution of the overdensity of the collapsed region an…
A Universal Bound on Excitations of Heavy Fields during Inflation
Thorsten Battefeld, R. C. Freitas
We discuss a universal bound on any excitation of heavy fields during inflation: the ratio of the heavy field's energy density to the one driving inflation must be less than the ma…
Polytropic equation of state and primordial quantum fluctuations
R. C. Freitas, S. V. B. Gonçalves
We study the primordial Universe in a cosmological model where inflation is driven by a fluid with a polytropic equation of state . We calculate the dynamics…