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Related papers: The Hubble IR cutoff in holographic ellipsoidal co…

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We have investigated the thermodynamical properties of the universe with dark energy. It is demonstrated that in a universe with spacial curvature the natural choice for IR cutoff could be the apparent horizon radius. We shown that any…

High Energy Physics - Theory · Physics 2011-07-04 Bin Liu , Xian-Ru Hu , Jian-Bo Deng

In this work, we propose a new dark energy model by applying the Barrow entropy and the holographic principle, with a time scale as IR cut off. Analysing the conformal time as well as universe's age as infrared cut-offs, we explore the…

General Relativity and Quantum Cosmology · Physics 2020-12-29 Umesh Kumar Sharma , Gunjan Varshney , Vipin Chandra Dubey

We propose an alternative model for the holographic dark energy in a non-flat universe. This new model differs from the previous one in that the IR length cutoff $L$ is taken to be exactly the event horizon size in a non-flat universe,…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-26 Jing-Fei Zhang , Ming-Ming Zhao , Jing-Lei Cui , Xin Zhang

The Hubble tension resides in a statistically significant discrepancy between early time and late time determinations of the Hubble constant. We discuss the Hubble tension within the Ellipsoidal Universe cosmological model. We suggest that…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-22 Paolo Cea

There is now strong evidence that the current energy density of the Universe is dominated by dark energy with an equation of state w<-1/3, which is causing accelerated expansion. The build-up of structure within such Universes is subject to…

Astrophysics · Physics 2008-11-26 Will J. Percival

The isotropy of the universal Hubble expansion is a fundamental tenet of physical cosmology, but it has not been precisely tested during the current epoch, when dark energy is dominant. Anisotropic expansion will produce a shearing velocity…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-19 Jeremy Darling

We study the cosmological consequences of interacting Tsallis holographic dark energy model in the framework of the fractal universe, in which, the Hubble radius is considered as the IR cut-off. We drive the equation of state (EoS)…

General Relativity and Quantum Cosmology · Physics 2020-06-24 S. Ghaffari , E. Sadri , A. H. Ziaie

We consider a cosmology in which a spherically symmetric large scale inhomogeneous enhancement or a void are described by an inhomogeneous metric and Einstein's gravitational equations. For a flat matter dominated universe the inhomogeneous…

Astrophysics · Physics 2008-11-26 J. W. Moffat

As soon as an interaction between holographic dark energy and dark matter is taken into account, the identification of IR cutoff with Hubble radius $H^{-1}$, in flat universe, can simultaneously drive accelerated expansion and solve the…

High Energy Physics - Theory · Physics 2010-01-06 Ahmad Sheykhi

In this work we consider a general function for the $c^{2}$ term that appears in the conventional expression for the holographic dark energy in a FLRW curved spacetime. The cut-off prospective is inspired in the apparent horizon length. By…

General Relativity and Quantum Cosmology · Physics 2018-12-07 Miguel Cruz , Samuel Lepe

We investigate the dynamics of the spatially flat universes submitted to isotropic tidal forces and adiabatic expansion under Einstein's equations. Surprisingly, the tendency to a high Hubble anisotropy at late times starts to appear as far…

General Relativity and Quantum Cosmology · Physics 2022-07-20 Fabio Scalco Dias , Leandro Gustavo Gomes , Luis Fernando Mello

In this paper, the holographic dark energy model is considered in Brans-Dicke theory where the holographic dark energy density $\rho_{\Lambda} =3c^2 M^{2}_{pl} L^{-2}$ is replaced with $\rho_{h}=3c^2 \Phi(t)L^{-2}$. Here…

Astrophysics · Physics 2009-06-23 Lixin Xu , Wenbo Li , Jianbo Lu

It has been persuasively argued that the number of the effective degrees of freedom of a macroscopic system is proportional to its area rather than to its volume. This entails interesting consequences for cosmology. Here we present a model…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Diego Pavon

Based on the entropy of anti-de Sitter black hole, a new holographic dark energy model has been proposed. When the Hubble horizon and particle horizon are chosen as the IR cutoff, the late-time accelerated expansion of universe is realized.…

General Relativity and Quantum Cosmology · Physics 2025-04-16 Qihong Huang , He Huang , Bing Xu , Kaituo Zhang

We consider the interacting holographic dark energy with new infrared cutoff (involving Hubble parameter and its derivative) in non-flat universe. In this context, we obtain the equation of state parameter which evolutes the universe from…

General Relativity and Quantum Cosmology · Physics 2015-06-12 M. Sharif , Abdul Jawad

We study some cosmological features of Tsallis holographic dark energy (THDE) in Cyclic, DGP and RS II braneworlds. In our setup, a flat FRW universe is considered filled by a pressureless source and THDE with the Hubble radius as the IR…

General Physics · Physics 2018-12-04 S. Ghaffari , H. Moradpour , J. P. Morais Graça , Valdir B. Bezerra , I. P. Lobo

The holographic cut-off in generalized dark energy (HDE) formalism depends on its cut-off. Following this, a four-parameter generalized entropy has recently been developed. It reduces to various known entropies for appropriate parameter…

General Physics · Physics 2025-10-08 Sanghati Saha , Ertan Güdekli , Surajit Chattopadhyay

A novel fractal structure for the cosmological horizon, inspired by COVID-19 geometry, which results in a modified area entropy, is applied to cosmology in order to serve dark energy. The constraints based on a complete set of observational…

Cosmology and Nongalactic Astrophysics · Physics 2020-09-18 Mariusz P. Dabrowski , Vincenzo Salzano

We study a holographic cosmological model in which the infrared cutoff is set by the Ricci's length and dark matter and dark energy do not evolve on their own but interact non-gravitationally with each other. This greatly alleviates the…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-25 Ivan Duran , Diego Pavon

The extended holographic dark energy model with the Hubble horizon as the infrared cutoff avoids the problem of the circular reasoning of the holographic dark energy model. Unfortunately, it is hit with the no-go theorem. In this paper, we…

General Relativity and Quantum Cosmology · Physics 2010-05-12 Jie Liu , Yungui Gong , Ximing Chen