49 citations · 138 across the 9 of their papers we have counts for
9 papers
Probing a cosmological model with a decaying-vacuum
Dennis Bessada, Oswaldo D. Miranda
In this work we study the evolution of matter-density perturbations for an arbitrary model, and specialize our analysis to the particular phenomenological law $Λ= Λ_0 + 3βH^…
DBI analog of a decaying vacuum cosmology
Dennis Bessada
In this work I discuss the dynamical and thermodynamical equivalence between a general k-essence scalar field cosmology and an arbitrary cosmological model with a decaying vacuum,…
Stochastic background of relic gravitons in a bouncing quantum cosmological model
Dennis Bessada, Nelson Pinto-Neto, Beatriz B. Siffert +1
The spectrum and amplitude of the stochastic background of relic gravitons produced in a bouncing universe is calculated. The matter content of the model consists of dust and radia…
Attractor Solutions in Tachyacoustic Cosmology
Dennis Bessada, William H. Kinney
We study the dynamical stability of "tachyacoustic" cosmological models, in which primordial perturbations are generated by a shrinking sound horizon during a period of deceleratin…
Non-Gaussian signatures of Tachyacoustic Cosmology
Dennis Bessada
I investigate non-Gaussian signatures in the context of tachyacoustic cosmology, that is, a noninflationary model with superluminal speed of sound. I calculate the full non-Gaussia…
Tachyacoustic Cosmology: An Alternative to Inflation
Dennis Bessada, William H. Kinney, Dejan Stojkovic +1
We consider an alternative to inflation for the generation of superhorizon perturbations in the universe in which the speed of sound is faster than the speed of light. We label suc…
CMB anisotropies induced by tensor modes in Massive Gravity
Dennis Bessada, Oswaldo D. Miranda
We study Gravitational Waves (GWs) in the context of Massive Gravity, an extension to General Relativity (GR) where the fluctuations of the metric have a nonzero mass, and specific…
Inflationary potentials in DBI models
Dennis Bessada, William H. Kinney, Konstantinos Tzirakis
We study DBI inflation based upon a general model characterized by a power-law flow parameter and speed of sound , where and are constant…
CMB Polarization and Theories of Gravitation with Massive Gravitons
Dennis Bessada, Oswaldo D. Miranda
We study in this paper three different theories of gravitation with massive gravitons - the modified Fierz-Pauli (FP) model, Massive Gravity and the bimetric theory proposed by Vis…