Related papers: A not so brief commentary on cosmological entropy …
We analyze spacetimes with horizons and study the thermodynamic aspects of causal horizons, suggesting that the resemblance between gravitational and thermodynamic systems has a deeper quantum mechanical origin. We find that the observer…
We propose a new entropy construct that generalizes the Tsallis, R\'enyi, Sharma-Mittal, Barrow, Kaniadakis, and Loop Quantum Gravity entropies and reduces to the Bekenstein-Hawking entropy in a certain limit. This proposal is applied to…
Black holes monopolize nowadays the center stage of fundamental physics. Yet, they are poorly understood objects. Notwithstanding, from their generic properties, one can infer important clues to what a fundamental theory, a theory that…
These lecture notes provide a concise, rapid and pedagogical introduction to several advanced topics in contemporary cosmology. The discussion of thermal history of the universe, linear perturbation theory, theory of CMBR temperature…
Motivated by recent work of one of us [1], we generalize this work to agegraphic tachyon models of dark energy with entropy correction terms arising from loop quantum gravity. We establish a connection between the entropy-corrected…
In these lectures I review the standard hot big-bang cosmology, emphasizing its successes, its shortcomings, and its major challenge---a detailed understanding of the formation of structure in the Universe. I then discuss the motivations…
We investigate a possibility of realizing the entropic force into the cosmology. A main issue is how the holographic screen is implemented in the Newtonian cosmology. Contrary to the relativistic realization of Friedmann equations, we do…
The information entropy is here investigated in the context of early and late cosmology under the hypothesis that distinct phases of universe evolution are entangled between them. The approach is based on the \emph{entangled state ansatz},…
Holographic dark energy theories present a fascinating interface to probe late-time cosmology, as guided by contemporary ideas about quantum gravity. In this work, we present a new holographic dark energy scenario designated Fractional…
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,…
A so-called "entropy-corrected holographic dark energy" (ECHDE), was recently proposed to explain the dark energy-dominated universe with the help of quantum corrections to the entropy-area relation in the setup of loop quantum cosmology.…
A short introduction to structure formation is given, followed by a discussion of the possible characteristics of the initial perturbations assuming a generic inflationary origin. Observational data related to large-scale structure and the…
In the framework of Brans-Dicke cosmology, we have studied the interacting power-law and logarithmic entropy-corrected holographic dark energy models with different cut-offs. The Brans-Dicke parameter is investigated versus the conditions…
By assuming that a dark component (dark energy) in the universe strictly obeys the holographic principle, that is, its entropy is one fourth of the apparent horizon, we find that the existence of the other dark component (dark matter) is…
Observational tests during the next decade may determine if the evolution of the Universe can be understood from fundamental physical principles, or if special initial conditions, coincidences, and new, untestable physical laws must be…
Inflation is considered one of the cornerstones of modern cosmology. However, the account of the origin of cosmic structure, as provided by the standard inflationary paradigm, is not fully satisfactory. The fundamental issue is the…
In a universe dominated by a small cosmological constant or by eternal dark energy with equation of state w < -1/3, observers are surrounded by event horizons. The horizons limit how much of the universe the observers can ever access. We…
Entropic-force cosmology provides, in contrast with dark energy descriptions, a concrete physical understanding of the accelerated expansion of the universe. The acceleration appears to be a consequence of the entropy associated with the…
A cosmological model of dark energy interacting with dark matter and another general component of the universe is investigated. We found general constraints on these models imposing an accelerated expansion. The same is also studied in the…
Bearing holographic dark energy hypothesis in mind, the ability of vacuum energy in describing the current accelerated universe is studied in the framework of Rastall theory. Here, in addition to the ordinary approach in which it is…