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We constrain cosmological parameters using only Hubble parameter data and quantify the impact of future Hubble parameter measurements on parameter estimation for the most typical dark energy models. We first constrain cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-27 Jia-Jia Geng , Rui-Yun Guo , Anzhong Wang , Jing-Fei Zhang , Xin Zhang

Assuming that the background geometry is filled with free gas consisting of matter and radiation and no phase transitions being occurred in the early Universe, we discuss the thermodynamics of this {\it closed} system using classical…

General Relativity and Quantum Cosmology · Physics 2015-05-30 A. Tawfik , H. Magdy

The values of Hubble constant H0 by direct measurements with standard distance ladder are typically larger than those obtained from the observation of cosmic microwave background and the galaxy survey with inverse distance ladder. On the…

Cosmology and Nongalactic Astrophysics · Physics 2024-04-26 Noriaki Kitazawa

This paper is a review on the observational Hubble parameter data that have gained increasing attention in recent years for their illuminating power on the dark side of the universe --- the dark matter, dark energy, and the dark age.…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-17 Tong-Jie Zhang , Cong Ma , Tian Lan

Dark energy observations may be explained within general relativity using an inhomogeneous Hubble-scale depression in the matter density and accompanying curvature, which evolves naturally out of an Einstein-de Sitter (EdS) model. We…

Cosmology and Nongalactic Astrophysics · Physics 2012-12-10 Sean February , Julien Larena , Mathew Smith , Chris Clarkson

Motivated by the Generalized Uncertainty Principle, covariance, and a minimum measurable time, we propose a deformation of the Heisenberg algebra and show that this leads to corrections to all quantum mechanical systems. We also demonstrate…

General Physics · Physics 2016-01-27 Mir Faizal , Mohammed M. Khalil , Saurya Das

In this letter we consider a dark energy model in which the energy density is a function of the Hubble parameter $H$ and its derivative with respect to time $\rho_{de}=3\alpha \ddot{H}H^{-1}+3\beta\dot{H}+3\gamma H^2$. The behavior of the…

General Relativity and Quantum Cosmology · Physics 2015-05-13 Songbai Chen , Jiliang Jing

We propose an analytical parametrization of the comoving distance and Hubble parameter to study the cosmic expansion history beyond the vanilla $\Lambda$CDM model. The parametrization is generalized enough to include the contribution of…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-22 Bikash R. Dinda

We study the Hubble parameter $H(z)$ in perturbed Friedmann universe and obtain an expression of the perturbed Hubble parameter $H(z,\textbf{n})$. We derive the Hubble parameter power spectrum by using the initial spectrum during inflation…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-19 Xi-Bin Li , Hao-Feng Qin , Zhi-Song Zhang , Tong-Jie Zhang

We use cosmological perturbation theory to study the backreaction effects of a self-consistent and well-defined cosmological averaging on the dynamics and the evolution of the Universe. Working with a perturbed…

General Relativity and Quantum Cosmology · Physics 2013-10-30 Iain A. Brown , Alan A. Coley , D. Leigh Herman , Joey Latta

We consider possible perturbations of the black hole event horizon induced by matter with spin, extending the derivation of the Hawking-Hartle formula (tidal heating) in the presence of torsion. When specialised to theories with a…

General Relativity and Quantum Cosmology · Physics 2023-03-29 Sudipta Hensh , Stefano Liberati , Vincenzo Vitagliano

In this paper, we propose a simple parametrization of the Hubble parameter H in order to explain the late time cosmic acceleration. We show that our proposal covers many models obtained in different schemes of parametrization under one…

General Relativity and Quantum Cosmology · Physics 2022-07-20 S. K. J. Pacif , R. Myrzakulov , S. Myrzakul

The disagreement between low- and high-redshift measurements of the Hubble parameter is emerging as a serious challenge to the standard model of cosmology. We develop a covariant cosmographic analysis of the Hubble parameter in a general…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-13 Roy Maartens , Jessica Santiago , Chris Clarkson , Basheer Kalbouneh , Christian Marinoni

We explore the cosmological dynamics of a teleparallel Gauss-Bonnet gravity model defined by the torsion scalar $T$ and the torsion-based Gauss-Bonnet invariant $T_{\mathcal{G}}$, deriving modified Friedmann equations for a flat FLRW…

General Relativity and Quantum Cosmology · Physics 2026-01-16 Santosh V. Lohakare , S. K. Maurya , Aaisha Al Qassabi , B. Mishra

We investigate a late-time cosmological model for a homogeneous and isotropic space-time in the Rastall theory. We explore the observational constraints on the Hubble parameter by using the latest cosmological datasets such as cosmic…

General Relativity and Quantum Cosmology · Physics 2026-01-01 Vinod Kumar Bhardwaj , Saibal Ray , Kazuharu Bamba , Akram Ali

The description of the cosmological expansion and its possible local manifestations via treating the proper conformal transformations as a coordinate transformation from a comoving Lorentz reference frame to an uniformly accelerated one is…

General Relativity and Quantum Cosmology · Physics 2008-06-03 L. M. Tomilchik

The present work deals with holographic dark energy models with Hubble horizon as the infra-red cut-off. The interaction rate between dark energy and dark matter has been reconstructed with three different choices of the interaction term.…

Cosmology and Nongalactic Astrophysics · Physics 2019-04-17 Purba Mukherjee , Ankan Mukherjee , H. K. Jassal , Ananda Dasgupta , Narayan Banerjee

The Hubble tension is analyzed in the framework of quantum cosmological approach. It is found that there arises a new summand in the expression for the total energy density stipulated by the quantum Bohm potential. This additional energy…

General Relativity and Quantum Cosmology · Physics 2024-02-13 V. E. Kuzmichev , V. V. Kuzmichev

We consider a cosmology with decaying metastable dark energy and assume that a decay process of this metastable dark energy is a quantum decay process. Such an assumption implies among others that the evolution of the Universe is…

General Relativity and Quantum Cosmology · Physics 2019-09-27 Aleksander Stachowski , Marek Szydlowski , Krzysztof Urbanowski

A Friedman cosmology is investigated based on scalar-tensor gravitation with general metric coupling and scalar potential functions. We show that for a broad class of such functions, the scalar field can be dynamically trapped using a…

General Relativity and Quantum Cosmology · Physics 2016-10-05 C. H. -T. Wang , J. A. Reid , A. St J. Murphy , D. Rodrigues , M. Al Alawi , R. Bingham , J. T. Mendonca , T. B. Davies