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Holographic dark energy cosmology, also known as entropic cosmology, provides a concrete physical understanding of the late accelerated expansion of the universe. The acceleration appears to be a consequence of entropy associated with…

General Relativity and Quantum Cosmology · Physics 2024-06-03 Facundo Abaca , Dario Javier Zamora

In this paper we investigate the possible direct, non-gravitational interaction between holographic dark energy (HDE) and dark matter. Firstly, we start with two simple models with the interaction terms $Q \propto \rho_{dm}$ and $Q \propto…

Cosmology and Nongalactic Astrophysics · Physics 2012-06-13 Zhenhui Zhang , Song Li , Xiao-Dong Li , Xin Zhang , Miao Li

We consider a new cosmological model (called $\tilde\Lambda$CDM) in which the vacuum energy interacts with matter and radiation, and test this model using the current cosmological observations. Using the CMB+BAO+SN (CBS) dataset to…

Cosmology and Nongalactic Astrophysics · Physics 2024-04-01 Li-Yang Gao , She-Sheng Xue , Xin Zhang

The dark energy dominated warm dark matter (WDM) model is a promising alternative cosmological scenario. We explore large-scale structure formation in this paradigm. We do this in two different ways: with the halo model approach and with…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Aurel Schneider , Robert E. Smith , Andrea V. Maccio , Ben Moore

This paper explores models of the FLRW universe that incorporate a time-varying cosmological term $\Lambda(t)$. Specifically, we assume a power-law form for the cosmological term as a function of the scale factor: $\Lambda(t)=\Lambda_{0}…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-14 M. Koussour , N. Myrzakulov , J. Rayimbaev

Motivated by our recent work \cite{set1}, we generalize this work to the interacting non-flat case. Therefore in this paper we deal with canonical, phantom and quintom models, with the various fields being non-minimally coupled to gravity,…

High Energy Physics - Theory · Physics 2014-11-20 M R Setare , Alberto Rozas-Fernández

The IR dynamics of effective holographic theories capturing the interplay between charge density and the leading relevant scalar operator at strong coupling are analyzed. Such theories are parameterized by two real exponents…

High Energy Physics - Theory · Physics 2010-12-06 C. Charmousis , B. Goutéraux , B. S. Kim , E. Kiritsis , Rene Meyer

In this paper, we study an interacting holographic dark energy model in the framework of fractal cosmology. The features of fractal cosmology could pass ultraviolet divergencies and also make a better understanding of the universe in…

General Relativity and Quantum Cosmology · Physics 2018-10-16 Ehsan Sadri , Martiros Khurshudyan , Surajit Chattopadhyay

In this paper we exploit the theory of the dynamical systems to study the dynamics of the standard cosmological model of the universe, which is known as the $\Lambda$CDM model. We assume that the matter content in our universe consists of…

General Physics · Physics 2022-09-07 Danijela Branković , Žarko Mijajlović

We study observational signatures of non-gravitational interactions between the dark components of the cosmic fluid, which can be either due to creation of dark particles from the expanding vacuum or an effect of the clustering of a…

Cosmology and Nongalactic Astrophysics · Physics 2019-12-10 Micol Benetti , Welber Miranda , Humberto A. Borges , Cassio Pigozzo , Saulo Carneiro , Jailson S. Alcaniz

We propose a method for constructing the specific heat for the universe by following standard definitions of classical thermodynamics, in a spatially flat homogeneous and isotropic spacetime. We use cosmography to represent the specific…

General Relativity and Quantum Cosmology · Physics 2013-04-11 Orlando Luongo , Hernando Quevedo

Motivated by the recent baryon acoustic oscillation measurements of DESI DR2 collaboration, this works presents an extended analysis of a cosmological model based on holographic dark energy within the framework of Unimodular Gravity. We…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-13 Francisco Plaza , Gabriel León , Lucila Kraiselburd

We discuss fits of cosmological dark energy models to the available data on high-redshift supernovae. We consider a conventional model with Cold Dark Matter and a cosmological constant (LambdaCDM), a model invoking super-horizon…

Astrophysics · Physics 2008-11-26 J. R. Ellis , N. E. Mavromatos , V. A. Mitsou , D. V. Nanopoulos

We investigate the properties of the FLRW flat cosmological models in which the vacuum energy density evolves with time, $\Lambda(t)$. Using different versions of the $\Lambda(t)$ model, namely quantum field vacuum, power series vacuum and…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 S. Basilakos , M. Plionis , J. Sola

Holographic cosmology offers a novel framework for describing the very early Universe in which cosmological predictions are expressed in terms of the observables of a three dimensional quantum field theory (QFT). This framework includes…

Cosmology and Nongalactic Astrophysics · Physics 2017-06-14 Niayesh Afshordi , Elizabeth Gould , Kostas Skenderis

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

The idea of a rapid sign-switching cosmological constant (mirror AdS-dS transition) in the late universe at $z\sim1.7$, known as the $\Lambda_{\rm s}$CDM model, has significantly improved the fit to observational data and provides a…

Cosmology and Nongalactic Astrophysics · Physics 2024-11-26 Özgür Akarsu , Antonio De Felice , Eleonora Di Valentino , Suresh Kumar , Rafael C. Nunes , Emre Özülker , J. Alberto Vazquez , Anita Yadav

We focus on the class of cosmological models with a time-evolving vacuum energy density of the form $\rho_\Lambda=C_0+C_1 H+C_2 H^2$, where $H$ is the Hubble rate. Higher powers of $H$ could be important for the early inflationary epoch,…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-13 Adria Gomez-Valent , Joan Sola

In this paper, we investigate the cosmological dynamics of teleparallel dark energy in the presence of nonzero spatial geometry. Extending previous analyses of nonminimal scalar-tensor theories in the torsion-based framework, we consider…

General Relativity and Quantum Cosmology · Physics 2025-05-28 Rocco D'Agostino , Francesco Bajardi

A cosmological model of an holographic dark energy interacting with dark matter throughout a decaying term of the form $Q=3(\lambda_1\rho_{DE} + \lambda_2\rho_m) H$ is investigated. General constraint on the parameters of the model are…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Norman Cruz , Samuel Lepe , Francisco Pena , Joel Saavedra
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