30 citations · 81 across the 9 of their papers we have counts for
9 papers · 1 filter
Perturbations in Bianchi Type-I spacetimes with varying Lambda, G
Alnadhief H. A. Alfedeel, Maye Elmardi, Amare abebe
In this paper, we investigate the evolution of cosmological perturbations within the context of Bianchi Type spacetimes. We consider models containing viscous fluids with evolv…
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…
Geodesics and Bending of Light around a BTZ Black Hole Surrounded by Quintessential Matter
Shubham Kala, Hemwati Nandan, Prateek Sharma +1
Various observations from cosmic microwave background radiation (CMBR), type Ia supernova and baryon acoustic oscillations (BAO) are strongly suggestive of an accelerated expansion…
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…
Shear-free conditions of a Chaplygin-Gas-dominated universe
Amare Abebe, Mudhahir Al Ajmi, Maye Elmardi +2
In this work, we revisit the shear-free conjecture of general relativity and show the violation of the well-known shear-free condition for perfect-fluid spacetimes. It had been sho…
The Chaplygin gas as a model for modified teleparallel gravity?
Shambel Sahlu, Joseph Ntahompagaze, Maye Elmardi +1
This paper explores the possibility of treating the exotic Chaplygin-gas (CG) fluid model as some manifestation of an gravitation. To this end, we use the different cosmolog…
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…
Chaplygin-gas Solutions of f(R) Gravity
Maye Elmardi, Amare Abebe, Abiy Tekola
We explore exact f(R) gravity solutions that mimic Chaplygin-gas inspired LCDM cosmology. Starting with the original and modified Chaplygin gas equations of state, we reconstruct t…
Irrotational-fluid cosmologies in fourth-order gravity
Amare Abebe, Maye Elmardi
In this paper, we explore classes of irrotational-fluid cosmological models in the context of f(R)-gravity in an attempt to put some theoretical and mathematical restrictions on th…