300 citations · 2.6k across the 72 of their papers we have counts for
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Cosmological dynamics of fourth order gravity: A compact view
Mohamed Abdelwahab, Rituparno Goswami, Peter K. S. Dunsby
We construct a compact phase space for flat FLRW spacetimes with standard matter described by a perfect fluid with a barotropic equation of state for general f(R) theories of gravi…
Covariant gauge-invariant perturbations in multifluid f(R) gravity
Amare Abebe, Mohamed Abdelwahab, Alvaro de la Cruz-Dombriz +1
We study the evolution of scalar cosmological perturbations in the (1+3)- covariant gauge-invariant formalism for generic theories of gravity. Extending previous works, we g…
On Shear-free perturbations of f(R) gravity
Amare Abebe, Rituparno Goswami, Peter K. S. Dunsby
Recently it was shown that if the matter congruence of a general relativistic perfect fluid flow in an almost FLRW universe is shear-free, then it must be either expansion or rotat…
Density growth in Kantowski-Sachs cosmologies with cosmological constant
Michael Bradley, Peter K. S. Dunsby, Mats Forsberg +1
In this work the growth of density perturbations in Kantowski-Sachs cosmologies with a positive cosmological constant is studied, using the 1+3 and 1+1+2 covariant formalisms. For…