37 citations · 207 across the 20 of their papers we have counts for
21 papers
Observational Constraints and Cosmic Growth Index of Realistic Gravity Frameworks using MCMC Analysis
Praveen Kumar Dhankar, Munyeshyaka Albert, Mohit Thakre +3
We present a comprehensive observational analysis of modified Gauss--Bonnet, or , gravity by investigating both the background cosmological expansion and sub-horizon linear m…
Testing Gauss-Bonnet Gravity with DESI BAO Data
Praveen Kumar Dhankar, Dalale Mhamdi, Albert Munyeshyaka +3
In the present paper, we observationally constrain f (G) gravity at the background level using Type Ia supernovae from the Pantheon Plus (PP) sample, cosmic chronometer (CC) data,…
Matter power spectrum in a power-law gravity
Albert Munyeshyaka, Praveen Kumar Dhankar, Joseph Ntahompagaze
Cosmological models based on gravity are efficient in fitting different observational datasets at both background and perturbation levels. This motivates the current study t…
Perturbations with bulk viscosity in modified chaplygin gas cosmology
Albert Munyeshyaka, Praveen Kumar Dhankar, Joseph Ntahompagaze
In the present work, we investigate cosmological perturbations of viscous modified chaplygin gas model. Using 1 + 3 covariant formalism, we define covariant and gauge invariant gra…
On covariant perturbations with scalar field in modified Gauss-Bonnet gravity
Albert Munyeshyaka, Joseph Ntahompagaze, Tom Mutabazi +1
We investigate cosmological perturbations of f(G) gravity in the presence of a scalar field. Using the 1 + 3 covariant formalism, we present the energy overdensity perturbation equ…
On Chaplygin models in f(G) gravity
Fidele Twagirayezu, Abraham Ayirwanda, Albert Munyeshyaka +3
The current work treats cosmological perturbation in a mixture of standard matter, Chaplygin gas as well as Gauss-bonnet fluids using a 1+3 covariant approach in the context of mod…
On 1 + 3 covariant perturbations of the quasi-Newtonian space-time in modified Gauss-Bonnet gravity
Albert Munyeshyaka, Joseph Ntahompagaze, Tom Mutabazi +1
The consideration of a 1 + 3 covariant approach to cold dark matter universe with no shear cosmological dust model with irrotational flows is developed in the context of f (G) grav…
Perturbations in the interacting vacuum
Albert Munyeshyaka, Joseph Ntahompagaze, Tom Mutabazi +4
In this study, we present the evolution of cosmological perturbations in a universe consisting of standard matter and interacting vacuum. We use the covariant formalism in…
Multifluid cosmology in f (G) gravity
Albert Munyeshyaka, Abraham Ayirwanda, Fidele Twagirayezu +1
The treatment of 1 + 3 covariant perturbation in a multifluid cosmology with the consideration of f (G) gravity, G being the Gauss-Bonnet term, is done in the present paper. We def…
On inflationary parameters in scalar-tensor theories
Beatrice Murorunkwere, Fidele Twagirayezu, Albert Munyeshyaka +2
The equivalence between and scalar-tensor theories is revisited, we consequently explored different models. After consideration of specific definition of the scalar f…
Large-scale structure power spectrum from scalar-tensor gravity
Joseph Ntahompagaze, Amare Abebe, Manasse R. Mbonye
This work deals with the computation of the power spectrum of large-scale structure using the dynamical system approach for a multi-fluid universe in scalar-tensor theory of gravit…
Cosmological perturbations in f(G) gravity
Albert Munyeshyaka, Joseph Ntahompagaze, Tom Mutabazi
We explore cosmological perturbations in a modified Gauss-Bonnet f(G) gravity, using a 1+3 covariant formalism. In such a formalism, we define gradient variables to get perturbed l…
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…
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…
A study of perturbations in scalar-tensor theory using 1+3 covariant approach
Joseph Ntahompagaze, Amare Abebe, Manasse R. Mbonye
This work discusses scalar-tensor theories of gravity, with a focus on the Brans-Dicke subclass, and one that also takes note of the latter's equivalence with gravitation th…
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…
On gravity in scalar-tensor theories
Joseph Ntahompagaze, Amare Abebe, Manasse Mbonye
We study gravity models in the language of scalar-tensor theories. The correspondence between gravity and scalar-tensor theories is revisited since gravity is…
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…