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Related papers: How early is early dark energy?

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Dark energy is usually parametrized as a perfect fluid with negative pressure and a certain equation of state. Besides, it is supposed to interact very weakly with the rest of the components of the universe and, as a consequence, there is…

Astrophysics · Physics 2015-05-13 Jose Beltran Jimenez , Antonio L. Maroto

We present a theoretical study of an early dark energy (EDE) model. The equation of state $\omega(z)$ evolves during the thermal history in a framework of a Friedmann-Lemaitre-Robertson-Walker Universe, following an effective…

Cosmology and Nongalactic Astrophysics · Physics 2020-09-17 Luz Ángela García , Leonardo Castañeda , Juan Manuel Tejeiro

If the equation of state of dark energy is anisotropic there will be additional quadrupole anisotropy in the cosmic microwave background induced by the time dependent anisotropic stress quantified in terms of $\Delta w$. Assuming that the…

Cosmology and Nongalactic Astrophysics · Physics 2010-04-14 Stephen Appleby , Richard Battye , Adam Moss

Dark energy, the enigmatic force driving the accelerated cosmic expansion of the universe, is conventionally described as a cosmological constant in the standard $\Lambda$CDM model. However, measurements from the Dark Energy Spectroscopic…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-26 Axel de la Macorra , Jose Agustin Lozano Torres

A new bound dark energy, BDE, cosmology has been proposed where the dark energy is the binding energy between light meson fields that condense a few tens of years after the big bang. It is reported that the correct dark energy density…

Cosmology and Nongalactic Astrophysics · Physics 2019-11-06 Rodger I. Thompson

Understanding the nature of the dark energy is one of the most important task in cosmology. In principle several cosmological observations can be used to discriminate amid a static cosmological constant contribution and a dynamical…

Astrophysics · Physics 2007-05-23 P. S. Corasaniti

We introduce EFTCAMB/EFTCosmoMC as publicly available patches to the commonly used CAMB/CosmoMC codes. We briefly describe the structure of the codes, their applicability and main features. To illustrate the use of these patches, we obtain…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Marco Raveri , Bin Hu , Noemi Frusciante , Alessandra Silvestri

We compare the latest observations of Cosmic Microwave Background (CMB) Anisotropies with the theoretical predictions of the standard scenario of structure formation. Assuming a primordial power spectrum of adiabatic perturbations we found…

Astrophysics · Physics 2009-11-07 Alessandro Melchiorri , Carolina Odman

The temperature and polarization anisotropies of the cosmic microwave background (CMB) have been used to set constraints on decaying dark matter models down to keV masses. In this work, we extend these limits down to the sub-keV mass range.…

Cosmology and Nongalactic Astrophysics · Physics 2024-08-27 Clara Xu , Wenzer Qin , Tracy R. Slatyer

For dynamical dark energy with the barotropic equation of state we determine the mean values of parameters and their confidence ranges together with other cosmological parameters on the basis of different combined datasets. The used…

Cosmology and Nongalactic Astrophysics · Physics 2018-11-13 O. Sergijenko

Injection of high energy electromagnetic particles around the recombination epoch can modify the standard recombination history and therefore the CMB anisotropy power spectrum. Previous studies have put strong constraints on the amount of…

Cosmology and Nongalactic Astrophysics · Physics 2019-12-19 Sandeep Kumar Acharya , Rishi Khatri

We study the performance of the spatially-flat dynamical dark energy (DE) $w_0w_a$CDM parameterization, with redshift-dependent DE fluid equation of state parameter $w(z) = w_0 + w_a z/(1+z)$, with and without a varying CMB lensing…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-15 Chan-Gyung Park , Javier de Cruz Perez , Bharat Ratra

The cosmic microwave background provides constraints on the annihilation and decay of light dark matter at redshifts between 100 and 1000, the strength of which depends upon the fraction of energy ending up in the form of electrons and…

Cosmology and Nongalactic Astrophysics · Physics 2013-04-29 James M. Cline , Pat Scott

Early dark energy (EDE) offers a solution to the so-called Hubble tension. Recently, it was shown that the constraints on EDE using Markov Chain Monte Carlo are affected by prior volume effects. The goal of this paper is to present…

Cosmology and Nongalactic Astrophysics · Physics 2023-08-16 Laura Herold , Elisa G. M. Ferreira

We investigate cosmological consequences of a generalized early dark energy (EDE) model where a scalar field behaves as dark energy at various cosmological epochs for a broad range of parameters such as the energy scale and the initial…

Cosmology and Nongalactic Astrophysics · Physics 2023-09-29 Tatsuki Kodama , Takumi Shinohara , Tomo Takahashi

Investigations on dark energy (DE) are currently inconclusive about its time evolution. Hints of this possibility do however glow now and then in the horizon. Herein we assess the current status of dynamical dark energy (DDE) in the light…

Cosmology and Nongalactic Astrophysics · Physics 2019-05-06 Joan Sola Peracaula , Adria Gomez-Valent , Javier de Cruz Perez

In this work we study the consequences of allowing non pressureless dark matter when determining dark energy constraints. We show that present-day dark energy constraints from low-redshift probes are extremely degraded when allowing this…

Cosmology and Nongalactic Astrophysics · Physics 2016-12-21 Isaac Tutusaus , Brahim Lamine , Alain Blanchard

We combine complementary datasets to constrain dark energy. Using standard Big Bang Nucleosynthesis and the observed abundances of primordial nuclides to put constraints on $\Omega_Q$ at temperatures near $T \sim 1MeV$, we find the strong…

Astrophysics · Physics 2015-06-24 Rachel Bean , Steen H. Hansen , Alessandro Melchiorri

In this paper, we combine the the latest observational data, including the WMAP five-year data (WMAP5), the baryon acoustic oscillations (BAO) and type Ia supernovae (SN) "union" compilation, and use the Markov Chain Monte Carlo method to…

Cosmology and Nongalactic Astrophysics · Physics 2010-05-11 Hong Li , Jun-Qing Xia

Type Ia supernova (SN Ia), galaxy clustering, and cosmic microwave background anisotropy (CMB) data provide complementary constraints on the nature of the dark energy in the universe. We find that the three-year Wilkinson Microwave…

Astrophysics · Physics 2010-11-11 Yun Wang , Pia Mukherjee
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