Related papers: Entropy evolution of universes with initial and fi…
Perhaps the deepest mystery of our accelerating Universe in expansion is the existence of a tiny and rigid cosmological constant, $\Lambda$. Its size is many orders of magnitude below the expected one in the standard model of particle…
In Ref. [S. Jalalzadeh, Phys. Lett. B 829 (2022) 137058], Jalalzadeh established that the thermodynamical entropy of a quantum-deformed black hole with horizon area $A$ can be written as $S_q=\pi\sin\left(\frac{A}{8G\mathcal N}…
An expanding universe is not expected to have a static vacuum energy density. The so-called cosmological constant $\Lambda$ should be an approximation, certainly a good one for a fraction of a Hubble time, but it is most likely a temporary…
We consider the de Sitter cosmology deformed by the presence of a thermal bath of radiation and/or time-dependent moduli fields. Depending on the parameters, either a first or second order phase transition can occur. In the first case, an…
In this paper, $F(\nu)$ cosmology is proposed for the accelerating universe with asymptotic de Sitter expansion in terms of Hankel function index $\nu$. To some extent, both the initial expansion during early inflation and the current…
We develop a cosmological model based on a quadratic equation of state p/c^2=-(\alpha+1){\rho^2}/{\rho_P}+\alpha\rho-(\alpha+1)\rho_{\Lambda} (where \rho_P is the Planck density and \rho_{\Lambda} the cosmological density) "unifying" vacuum…
We study thermodynamics of cosmological models in the Horava-Lifshitz theory of gravity, and systematically investigate the evolution of the universe filled with a perfect fluid that has the equation of state $p=w\rho$, where $p$ and $\rho$…
We develop further the investigations in arXiv:2210.12963 [hep-th] on de Sitter space, extremal surfaces and time entanglement. We discuss the no-boundary de Sitter extremal surface areas as certain analytic continuations from $AdS$ while…
We take the view that the standard von Neumann definition, in which the entropy $S^{vN}$ of a pure state is zero, is in evident conflict with the statement of the second law that the entropy of the universe $S_{univ}$ increases in…
Recent developments in cosmology suggest that much of the universe is in a state of explosive, accelerated expansion, called inflation. We live in a "bubble" where inflation has ended, and other bubbles with diverse properties are…
Within an inherently classical perspective, there is always an unavoidable energy cost associated with the information deletion and this common lore is at the heart of the Landauer's conjecture that does not impose, per se, any relevant…
We study the evolution of the configuration entropy for different combinations of $\Omega_{m0}$ and $\Omega_{\Lambda0}$ in the flat $\Lambda$CDM universe and find that the cosmological constant plays a decisive role in controlling the…
In standard cosmology, with the evolution of the universe, the matter density and thermodynamic pressure gradually decreases. Also in course of evolution, the matter in the universe obeys (or violates) some restrictions or energy…
The acceleration of the cosmic expansion revealed by supernova observations indicates that the present universe is dominated by repulsive dark energy. It is natural that the coupling between the dark energy and the attractive gravity has to…
We compute the quantum circuit complexity of the evolution of scalar curvature perturbations on expanding backgrounds, using the language of squeezed vacuum states. In particular, we construct a simple cosmological model consisting of an…
The thermal time hypothesis proposed by Rovelli [1] regards the physical basis for the flow of time as thermodynamical and provides a definition of the temperature for some special cases. We verify this hypothesis in the case of de Sitter…
In this work we study the cosmological evolution of a two component model with non-relativistic dark matter and decaying vacuum of the form $\Lambda = \Lambda_0 + 3 \beta H^2.$ We contrast the model the model with the supernovae data and…
Recent theoretical progress indicates that spacetime and gravity emerge together from the entanglement structure of an underlying microscopic theory. These ideas are best understood in Anti-de Sitter space, where they rely on the area law…
Inflation has been the leading early universe scenario for two decades, and has become an accepted element of the successful `cosmic concordance' model. However, there are many puzzling features of the resulting theory. It requires both…
Nonlinear perturbations of Friedmann-Lemaitre cosmologies with dust and a positive cosmological constant have recently attracted considerable attention. In this paper our first goal is to compare the evolution of the first and second order…