15 citations · 15 across the 1 of their papers we have counts for
6 papers
On multifluid perturbations in scalar-tensor cosmology
Joseph Ntahompagaze, Shambel Sahlu, Amare Abebe +1
In this paper the scalar-tensor theory is applied to the study of perturbations in a multi-fluid universe, using the 1+3 covariant approach. Both scalar and harmonic decompositions…
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…
Accelerating universe in modified teleparallel gravity theory
Shambel Sahlu, Joseph Ntahompagaze, Amare Abebe +1
This paper studies the cosmology of accelerating expansion of the universe in modified teleparallel gravity theory. We discuss the cosmology of gravity theory and its impl…
Scalar perturbations in gravity using the covariant approach
Shambel Sahlu, Joseph Ntahompagaze, Amare Abebe +2
The cosmological scalar perturbations of standard matter are investigated in the context of extended teleparallel gravity theories using the covariant formalism. After…
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…
Inflation constraints for classes of f(R) models
Joseph Ntahompagaze, Jean Damascene Mbarubukeye, Shambel Sahlu +1
In this paper, we explore the equivalence between two theories, namely f(R) and scalar-tensor theories of gravity. We use this equivalence to explore several f(R) toy models focusi…