Related papers: Emergence of space and cosmic evolution based on e…
A very interesting new proposal on the origin of the cosmic expansion was recently suggested by Padmanabhan [arXiv:1206.4916]. He argued that the difference between the surface degrees of freedom and the bulk degrees of freedom in a region…
In this paper, a general entropy-corrected FRW cosmological model has been presented in which a deceleration-to-acceleration transition occurs according to recent observations. We found that the case for the flat universe ($k=0$), supported…
We study a closed model of a universe filled with viscous fluid and quintessence matter components. The dynamical equations imply that the universe might look like an accelerated flat Friedmann-Robertson-Walker (FRW) universe at low…
Very recently, Verlinde considered a theory in which space is emergent through a holographic scenario, and proposed that gravity can be explained as an entropic force caused by changes in the information associated with the positions of…
Modified theories of gravity have recently been studied by several authors as possibly viable alternatives to the cosmological concordance model. Such theories attempt to explain the accelerating expansion of the universe by changing the…
Motivated by the notion that the mathematics of gravity can be reproduced from a statistical requirement of maximal entropy, we study the consequence of introducing an entropic source term in the Einstein-Hilbert action. For a spatially…
For several independent reasons, the idea that notorious sources of entropy could exist in the Universe has been recently revived. Taking advantage of a new framework accounting for non-equilibrium processes in cosmology, we explicitly…
In this paper, dark energy is modelled via a spherically symmetric quintessence scalar field $\varphi$, the dynamics of which are found to be analogous to a pendulum. This is due to a driving axion potential $V(\left|\varphi\right|)$, whose…
To explain the cosmic speed up, brought to light by the recent SNIa and CMB observations, we propose the following: a) In a spacetime endowed with a FRW metric, we choose an empirical scale factor that best explains the observations. b) We…
In this article, we study the expanding nature of universe in the contest of $f(R,L_m)$ gravity theory, here $ R $ represents the Ricci scalar and $ L_m $ is the matter Lagrangian density. With a specific form of $ f(R,L_m) $, we obtain the…
The contemporary physics has revealed growing evidences that the emergence can be applied to not only biology and condensed matter systems but also gravity and spacetime. We observe that noncommutative spacetime necessarily implies emergent…
We construct cosmological model in nonmetricity scalar functional gravitational Lagrangian $f(Q)$ which describes the dynamical evolution of the late accelerating universe. Cosmological models are constructed considering different…
The evolution of the dark energy parameter within the scope of a spatially homogeneous and isotropic Friedmann-Robertson-Walker (FRW) model filled with perfect fluid and dark energy components is studied by generalizing the recent results…
A cosmological model with perfect fluid and self-interacting quintessence field is considered in the framework of the spatially flat Friedmann-Robertson-Walker (FRW) geometry. By assuming that all physical quantities depend on the volume…
Assuming a flat Friedmann-Robertson-Walker cosmology with a single perfect fluid, we propose a pressure-density ratio that evolves as a specific universal function of the scale parameter. We show that such a ratio can indeed be consistent…
In the contemporary Cosmology, dark energy is modeled as a perfect fluid, having a very simple equation of state: pressure is proportional to dark energy density. As an alternative, I propose a more complex equation of state, with pressure…
The discovery that the expansion of the universe is accelerating in time is a major discovery which still awaits adequate explanation. It is generally agreed that this implies a cosmic repulsion as a result of the existence of a…
A dynamical estimate is given for the Boltzmann entropy of the Universe, under the simplifying assumptions provided by Newtonian cosmology. We first model the cosmological fluid as the probability fluid of a quantum-mechanical system. Next,…
The effective equation of state of normal matter is changed in theories where the size of the compact space depends upon the local energy density. In particular we show how the dilution of a fluid due to the expansion of the universe can be…
Within the recently proposed structured FRW model universe the averaged Einstein equations are derived. The backreaction turns out to have an interesting behavior. Its equivalent density and pressure, being proportional, are negative at…