Related papers: Entropic Accelerating Universe
It is argued that the discovery of cosmic acceleration could have been anticipated on thermodynamic grounds, namely, the generalized second law and the approach to equilibrium at large scale factor. Therefore, the existence of dark energy…
Is Dark Energy justified as an alternative to the cosmological constant $\Lambda$ in order to explain the acceleration of the cosmic expansion ? It turns out that a straightforward dimensional analysis of Einstein equation provides us with…
Acceleration of the universe is obtained from a model of non-relativistic particles with a short-range attractive interaction, at low enough temperature to produce a Bose-Einstein condensate. Conditions are derived for negative-pressure…
We discuss the notion of generating a cosmic inflation without any big bang singularity. It has been proved recently by Good and Linder (arXiv : 2503.02380v1) that such an expansion of the universe can be driven by quantum fluctuations…
A long-standing topic of interest in the general theory of relativity is the embedding of curved spacetimes in higher-dimensional flat spacetimes. The main purpose this paper is to show that the embedding theory can account for the…
The spacial expansion of the universe could be described as a tendency for satisfying holographic equipartition which inevitably demands the presence of dark energy. We explore whether this novel idea proposed by Padmanabhan give any…
The acceleration of the cosmic expansion has been discovered as a consequence of redshift Supernovae data. In the usual way, this cosmic acceleration is explained by the presence of a positive cosmological constant or quantum vacuum energy,…
We elaborate on the proposal that the observed acceleration of the Universe is the result of the backreaction of cosmological perturbations, rather than the effect of a negative-pressure dark-energy fluid or a modification of general…
Accelerated expansion of the Universe may result from an anti-frictional force that is self-consistently exerted on cold dark matter (CDM). Cosmic anti-friction is shown to give rise to an effective negative pressure of the cosmic medium.…
Astronomical observations have shown that the expansion of the universe is at present accelerating, consistently with a constant negative pressure or tension. This is a major puzzle because we do not understand why this tension is so small…
The reason for the present accelerated expansion of the Universe stands as one of the most profound questions in the realm of science, with deep connections to both cosmology and fundamental physics. From a cosmological point of view,…
In this paper we study the viability of an entropic cosmological model. The effects of entropic gravity are derived from a modified entropy-area relationship with a volumetric entropy term. This model describes a late time limit cosmic…
Explaining the well established observation that the expansion rate of the universe is apparently accelerating is one of the defining scientific problems of our age. Within the standard model of cosmology, the repulsive 'dark energy'…
Cosmic acceleration is explained quantitatively, as an apparent effect due to gravitational energy differences that arise in the decoupling of bound systems from the global expansion of the universe. "Dark energy" is a misidentification of…
We derive the radial acceleration of stars in galaxies by using basic features of thermodynamics, statistical mechanics and general relativity. We assume that the "dark" component of the radial acceleration is originated from the reaction…
We reconsider the entropic-force model in which both kind of Hubble terms ${\dot H}$ and $H^{2}$ appear in the effective dark energy (DE) density affecting the evolution of the main cosmological functions, namely the scale factor,…
Astronomical observations indicate an accelerated cosmic expansion, the cause of which is explained by the action of `dark energy'. Here we show that in discrete expanding space-time, only a tiny fraction of the vacuum fluctuations can…
We investigate the growth of cosmic structures in the thermodynamically consistent generalised mass-to-horizon entropic cosmology (MHEC). For the Bekenstein case the entropic energy density augments the Friedmann equations without modifying…
Adopting the thin-layer improved brick-wall method, we investigate the thermodynamics of a black hole embedded in a spatially flat Friedmann-Robertson-Walker universe. We calculate the temperature and the entropy at every apparent horizon…
A new model of accelerating expansion of the universe is presented. A de Sitter solution in vacuum and a exact solution with the dust mater source are obtained. A new explanation of the acceleration of the cosmic expansion is given. In is…