Now showing items 1-6 of 6

    • Anisotropic solutions in modified gravity 

      Abebe, Amare; Momeni, Davood; Myrzakulov, Ratbay (IOP Publishing, 2017)
      Anisotropic but homogeneous, shear-free cosmological models with imperfect matter sources in f(R) gravity are investigated. The relationship between the anisotropic stresses and the electric part of the Weyl tensor, as ...
    • Chaplygin-gas solutions of f(R) gravity 

      Elmardi, Maye; Abebe, Amare; Tekola, Abiy (World Scientific Publishing, 2016)
      We explore exact f(R) gravity solutions that mimic Chaplygin-gas inspired CDM cosmology. Starting with the original, generalized and modified Chaplygin gas equations of state, we reconstruct the forms of f(R) Lagrangians. ...
    • Cosmological Chaplygin gas as modified gravity 

      Elmardi, Maye; Abebe, Amare (IOP Publishing, 2017)
      In the scramble for the understanding of the nature of dark matter and dark energy, it has recently been suggested that the change of behavior of the missing energy density might be regulated by the change in the equation ...
    • Integrability conditions of quasi-Newtonian cosmologies in modified gravity 

      Abebe, Amare; Dunsby, Peter K.S.; Solomons, Deon (World Scientific, 2017)
      We investigate the integrability conditions of a class of shear-free perfect-fluid cosmological models within the framework of anisotropic fluid sources, applying our results to f(R) dark energy models. Generalizing earlier ...
    • On f(R) gravity in scalar-tensor theories 

      Ntahompagaze, Joseph; Abebe, Amare; Mbonye, Manasse (World Scientific, 2017)
      We study f(R) gravity models in the language of scalar–tensor (ST) theories. The correspondence between f(R) gravity and ST theories is revisited since f(R) gravity is a subclass of Brans–Dicke models, with a vanishing ...
    • Shear-free anisotropic cosmological models in f (R) gravity 

      Abebe, Amare; Momeni, Davood; Myrzakulov, Ratbay (Springer, 2016)
      We study a class of shear-free, homogeneous but anisotropic cosmological models with imperfect matter sources in the context of f(R) gravity. We show that the anisotropic stresses are related to the electric part of the ...