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Related papers: A novel early Dark Energy model

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The recent cosmological picture contains a significant tension indicating that our standard $\Lambda$CDM picture may be incomplete. Early Dark Energy models can alleviate the Hubble tension, by assuming an early acceleration that could…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-27 Teodora M. Matei , Cristian Croitoru , Tiberiu Harko

The fractional dark energy (FDE) model describes the accelerated expansion of the Universe through a nonrelativistic gas of particles with a noncanonical kinetic term. This term is proportional to the absolute value of the three-momentum to…

General Relativity and Quantum Cosmology · Physics 2022-03-21 Ricardo G. Landim

In this paper, we employ two model-independent approaches, including redshift binning method and polynomial interpolation method, to reconstruct dark energy (DE) equation of state (EoS) $w(z)$ and DE density function $f(z)$. Our analysis…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-18 Jun-Xian Li , Shuang Wang

The dark energy model with the equation of state p_d=-rho_d - A rho_d^alpha is studied. The model comprises and provides realization of several types of singularities in different parameter regimes: the divergence of the dark energy density…

Astrophysics · Physics 2008-11-26 Hrvoje Stefancic

We apply a new non-parametric Bayesian method for reconstructing the evolution history of the equation-of-state $w$ of dark energy, based on applying a correlated prior for $w(z)$, to a collection of cosmological data. We combine the latest…

Cosmology and Nongalactic Astrophysics · Physics 2013-03-20 Gong-Bo Zhao , Robert G. Crittenden , Levon Pogosian , Xinmin Zhang

Numerous upcoming observations, such as WFIRST, BOSS, BigBOSS, LSST, Euclid, and Planck, will constrain dark energy (DE)'s equation of state with great precision. They may well find the ratio of pressure to energy density, $w$, is -1,…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Zachary Slepian , J. Richard Gott , Joel Zinn

The current paper provides a comprehensive examination of a dark energy cosmological model in the classical regime, in which a generic scalar field is regarded as a dark energy source. Einstein's field equations are solved in model…

General Relativity and Quantum Cosmology · Physics 2022-09-07 Ritika Nagpal , Shibesh Kumar Jas Pacif , Abhishek Parida

In models where dark matter and dark energy interact non-minimally, the total amount of matter in a fixed comoving volume may vary from the time of recombination to the present time due to energy transfer between the two components. This…

Cosmology and Nongalactic Astrophysics · Physics 2012-10-16 P. P. Avelino , H. M. R. da Silva

The property of dark energy and the physical reason for acceleration of the present universe are two of the most difficult problems in modern cosmology. The dark energy contributes about two-thirds of the critical density of the present…

Astrophysics · Physics 2009-11-13 F. Y. Wang , Z. G. Dai

We examine a cosmological model with a dark energy density of the form $\rho_{DE}(t)=\rho_X(t)+\rho_Z(t)$, where $\rho_X$ is the component that accelerates the Hubble expansion at late times and $\rho_Z(t)$ is an extra contribution…

Cosmology and Nongalactic Astrophysics · Physics 2012-06-22 Michele Maggiore , Lukas Hollenstein , Maud Jaccard , Ermis Mitsou

The Hubble constant estimated from the CMB measurements shows large disagreement with the locally measured value. This inconsistency is called the Hubble tension and is vastly studied in recent years. Early Dark Energy (EDE) gives a few…

Cosmology and Nongalactic Astrophysics · Physics 2022-10-13 Kentaro Kojima , Yuri Okubo

We use a variant of principal component analysis to investigate the possible temporal evolution of the dark energy equation of state, w(z). We constrain w(z) in multiple redshift bins, utilizing the most recent data from Type Ia supernovae,…

Cosmology and Nongalactic Astrophysics · Physics 2010-01-07 Paolo Serra , Asantha Cooray , Daniel E. Holz , Alessandro Melchiorri , Stefania Pandolfi , Devdeep Sarkar

To describe the dark side of the Universe, we adopt a novel approach where dark energy is explained as an electrically charged majority of dark matter. Dark energy, as such, does not exist. The Friedmann equation at the present time…

General Relativity and Quantum Cosmology · Physics 2024-04-16 Paul H. Frampton

We study the interacting agegraphic dark energy (ADE) model in non-flat universe by means of statefinder diagnostic and $w-w^{\prime}$ analysis. First, the evolution of EoS parameter ($w_d$) and deceleration parameter ($q$) in terms of…

General Relativity and Quantum Cosmology · Physics 2014-11-20 M. Malekjani , A. Khodam-Mohammadi

We investigate the observational consequences of a novel class of stable interacting dark energy (IDE) models, featuring interactions between dark matter (DM) and dark energy (DE). In the first part of our work, we start by considering two…

Cosmology and Nongalactic Astrophysics · Physics 2018-12-13 Weiqiang Yang , Supriya Pan , Eleonora Di Valentino , Rafael C. Nunes , Sunny Vagnozzi , David F. Mota

Using the SNe Ia data we determine the three parameters in the power-law expanding universe model with time-dependent power \cite{W}. Inputting $H_0$ and $t_0$, then we find the $\dot{a}-t$ evolution curve with $m=5.0$ and $q_0=-0.90$ can…

Astrophysics · Physics 2007-05-23 Yi-Huan Wei

We study the integrated Sachs-Wolfe (ISW) effect using a model-independent parameterization of the dark energy equation of state. Cosmic variance severely restricts the class of models distinguishable from Lambda-CDM. In particular if the…

Astrophysics · Physics 2009-11-07 P. S. Corasaniti , B. A. Bassett , C. Ungarelli , E. J. Copeland

One of the goals of current cosmological studies is the determination of the expansion and acceleration rates of the universe as functions of redshift, and the determination of the properties of the dark energy that can explain these…

Astrophysics · Physics 2009-11-10 Ruth A. Daly , S. G. Djorgovski

We explore the implications of a rapid appearance of dark energy between the redshifts ($z$) of one and two on the expansion rate and growth of perturbations. Using both Gaussian process regression and a parameteric model, we show that this…

Cosmology and Nongalactic Astrophysics · Physics 2020-01-17 Ryan E. Keeley , Shahab Joudaki , Manoj Kaplinghat , David Kirkby

The discovery of dark energy (DE) as the physical cause for the accelerated expansion of the Universe is the most remarkable experimental finding of modern cosmology. However, it leads to insurmountable theoretical difficulties from the…

High Energy Physics - Theory · Physics 2008-11-26 Joan Sola