20 citations · 28 across the 9 of their papers we have counts for
9 papers
Confronting the Chaplygin gas with data: background and perturbed cosmic dynamics
Shambel Sahlu, Heba Sami, Renier Hough +3
In this paper, we undertake a unified study of background dynamics and cosmological perturbations in the presence of the Chaplygin gas. This is done by first constraining the backg…
Cosmic hierarchy in gravity
Heba Sami, Amare Abebe
In this contribution, we investigate hierarchical nature of large-scale structure clustering through the oscillatory nature of the solutions of the Schrödinger-like Friedmann equat…
Covariant density and velocity perturbations of the quasi-Newtonian cosmological model in gravity
Heba Sami, Shambel Sahlu, Amare Abebe +1
We investigate classes of shear-free cosmological dust models with irrotational fluid flows within the framework of gravity. In particular, we use the covariant form…
Perturbations of quasi-Newtonian universes in scalar-tensor gravity
Heba Sami, Amare Abebe
In this contribution, we consider the equivalence between gravity and scalar-tensor theories to study the evolution of scalar cosmological perturbations in the covar…
Perturbations in a Chaplygin gas Cosmology
Shambel Sahlu, Heba Sami, Anna-Mia Swart +3
In this paper we study the perturbations of a cosmic multi-fluid medium consisting of radiation, dust and a Chaplygin gas. To do so, we follow the 1 + 3 covariant formalism and der…
Oscillating cosmological correlations in f(R) gravity
Neo Namane, Heba Sami, Amare Abebe
The purpose of this paper is to investigate the oscillatory behavior of the universe through a Schrödinger-like Friedmann equation and a modified gravitational background described…
Quasi-Newtonian Cosmological Models in Scalar-Tensor Theories of Gravity
Heba Sami, Amare Abebe
In this contribution, classes of shear-free cosmological dust models with irrotational fluid flows will be investigated in the context of scalar-tensor theories of gravity. In part…
Inflationary f(R) cosmologies
Heba Sami, Joseph Ntahompagaze, Amare Abebe
This paper discusses a simple procedure to reconstruct f (R)-gravity models from exact cosmological solutions of the Einstein field equations with a noninteracting classical scalar…
Reconstructing f(R) Gravity from a Chaplygin Scalar Field in de Sitter Spacetimes
Heba Sami, Neo Namane, Joseph Ntahompagaze +2
We present a reconstruction technique for models of gravity from the Chaplygin scalar field in flat de Sitter spacetimes. Exploiting the equivalence between gravity a…