Related papers: Cosmology with modified continuity equation in asy…
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 gravity, subject to certain conditions on the function f. We then…
The paper deals with cosmology in modified f(T) gravity theory. With some phenomenological choices for the function f(T) it is possible to have cosmological solutions describing different phases of the evolution of the Universe for the…
This work considers how exponential corrections to the Bekenstein-Hawking entropy formula affect the thermodynamic behavior of the FLRW cosmological model. These corrections drastically change the form of the Friedman field equations…
A spherically symmetric comoving fluid solution of Einstein's equations is adapted for cosmological application by extending the geometry of standard FRW cosmology using a generalised curvature term. The resulting model retains many of the…
In this paper, we study $F(R)$ gravity by Hu-Sawicki model in Friedmann-Lema\^{\i}tre-Robertson-Walker (FLRW) background. The Friedmann equations are calculated by modified gravity action, and then the obtained Friedmann equations are…
The dynamics of perfect fluid as a source in the context of modified gravity, specifically $f(Q,T)$ gravity, are examined within the Friedmann-Lema\^itre-Robertson-Walker (FLRW) cosmological model. This gravity is a generic function of the…
We study the quantum cosmology of a quadratic $f(R)$ theory with a FRW metric, via one of its equivalent Horndeski type actions, where the dynamics of the scalar field is induced. The classical equations of motion and the Weeler-deWitt…
One of the most enduring and unresolved challenges in modern theoretical and observational cosmology is the fine-tuning and coincidence problems associated with the cosmological constant. Rather than attempting to reconcile these issues…
We develop a cosmological theory in which the evolution of the universe is controlled by the cosmological constant and dominated by the associated vacuum energy. The universe starts as a classical de Sitter space with an infinite effective…
Recently, it was formulated a teleparallel theory called $f(T,B)$ gravity which connects both $f(T)$ and $f(R)$ under suitable limits. In this theory, the function in the action is assumed to depend on the torsion scalar $T$ and also on a…
Perturbative quantum gravity formalism is applied to compute the lowest order corrections to the classical spatially flat cosmological FLRW solution (for the radiation). The presented approach is analogous to the approach applied to compute…
Possible analogies between vacuum state and quantum fluid provide a model to study vacuum energy density induced by thermal corrections, space-time curvature, boundary conditions and quantum back-reaction. We find that vacuum energy density…
The paper deals with $f(R)$ gravity theory in the background of inhomogeneous FLRW--type space time model. With proper choice of the inhomogeneous metric function it is possible to have an emergent scenario for the $f(R)$--cosmology.…
We explore the possibility of a consistent cosmology based on the gauge-fixing independent running of the gravitational and cosmological constants ($G$ and $\Lambda$) in the framework of effective quantum gravity. In particular, their…
In this paper we present the techniques for computing cosmological bounces in polynomial $f(R)$ theories, whose order is more than two, for spatially flat FLRW spacetime. In these cases the conformally connected Einstein frame shows up…
A detailed study of the various cosmological aspects in massive gravity theory has been presented in the present work. For the homogeneous and isotropic FLRW model, the deceleration parameter has been evaluated, and, it has been examined…
Loop quantum cosmology of the k=0 FRW model (with a massless scalar field) is shown to be exactly soluble if the scalar field is used as the internal time already in the classical Hamiltonian theory. Analytical methods are then used i) to…
Motivated by the conjecture that the cosmological constant problem could be solved by strong quantum effects in the infrared we use the exact flow equation of Quantum Einstein Gravity to determine the renormalization group behavior of a…
We discuss how to extract information about the cosmological constant from the Wheeler-DeWitt equation, considered as an eigenvalue of a Sturm-Liouville problem in a de Sitter and Anti-de Sitter background. The equation is approximated to…
It has been known for some time that the cosmological Friedmann equation deduced from General Relativity can be also obtained within the Newtonian framework under certain assumptions. We use this result together with quantum corrections to…