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A modified version of the Ozer and Taha nonsingular cosmological model is presented on the assumption that the universes radius is complex if it is regarded as empty, but it contains matter when the radius is real. It also predicts the values: Omega_M =rho_M /rho_C approx 4/3, Omega_V = rho_V /rho_C approx 2/3, and Omega_ = rho_ /rho_C << 1 in the present nonrelativistic era, where rho_M = matter density, rho_V = vacuum density, rho_= negative energy density and rho_{C} = critical density.
In the present paper, we consider a model of non-minimal modified Yang-Mills theory in the Friedmann-Robertson-Walker cosmology, in which the Yang-Mills field couples to the scalar curvature through a function of its first invariant. We show that cos
A spatially homogeneous and locally rotationally symmetric Bianchi type-II cosmological model under the influence of both shear and bulk viscosity has been studied. Exact solutions are obtained with a barotropic equation of state between thermodynami
We propose a modified gravity theory that propagates only two local gravitational degrees of freedom and that does not have an Einstein frame. According to the classification in JCAP 01 (2019) 017 [arXiv:1810.01047 [gr-qc]], this is a type-II minimal
We derive a model of dark energy which evolves with time via the scale factor. The equation of state $omega=(1-2alpha)/(1+2alpha)$ is studied as a function of a parameter $alpha$ introduced in this model. In addition to the recent accelerated expansi
In the context of the recently proposed type-II minimally modified gravity theory, i.e. a metric theory of gravity with two local physical degrees of freedom that does not possess an Einstein frame, we study spherically symmetric vacuum solutions to