English
Related papers

Related papers: How isotropic is dark energy?

200 papers

A variety of observational tests seem to suggest that the universe is anisotropic. This is incompatible with the standard dogma based on adiabatic, rotationally invariant perturbations. We point out that this is a consequence of the…

Astrophysics · Physics 2009-11-11 Richard A. Battye , Adam Moss

We search for physically consistent realizations of evolving dark energy suggested by the cosmological fit of DESI, Planck and Supernovae data. First we note that any lagrangian description of the standard Chevallier-Polarski-Linder (CPL)…

Cosmology and Nongalactic Astrophysics · Physics 2024-11-18 Alessio Notari , Michele Redi , Andrea Tesi

We investigate the behaviour of dark energy using the recently released supernova data of Riess et al ~(2004) and a model independent parameterization for dark energy (DE). We find that, if no priors are imposed on $\Omega_{0m}$ and $h$, DE…

Astrophysics · Physics 2009-11-10 Ujjaini Alam , Varun Sahni , A. A. Starobinsky

The standard cosmological model is in the midst of a stress test, thanks to the tension between supernovae-based measurements of the Hubble constant $H_{0}$ and inferences of its values from Cosmic Microwave Background (CMB) anisotropies.…

Cosmology and Nongalactic Astrophysics · Physics 2024-11-05 K. Rezazadeh , A. Ashoorioon , D. Grin

We investigate how the dark energy properties impact the constraints on the total neutrino mass in interacting dark energy (IDE) models. In this study, we focus on two typical interacting dynamical dark energy models, i.e., the interacting…

Cosmology and Nongalactic Astrophysics · Physics 2019-08-13 Lu Feng , Hai-Li Li , Jing-Fei Zhang , Xin Zhang

We investigate generalized Einstein-Aether theories that are compatible with the Planck Cosmic Microwave Background (CMB) temperature anisotropy, polarisation, and lensing data. For a given dark energy equation of state, $w_{\rm de}$, we…

Cosmology and Nongalactic Astrophysics · Physics 2019-02-20 Damien Trinh , Francesco Pace , Richard A. Battye , Boris Bolliet

In our study, we explored the properties of a spatially homogeneous and anisotropic Bianchi type V I0 Universe. Our investigation centered on integrating cosmic domain walls into the f(R, T) theory of gravitation, initially proposed by…

General Relativity and Quantum Cosmology · Physics 2024-03-05 V. R. Patil , J. L. Pawde , R. V. Mapari , S. K. Waghmare

The late-time linear Integrated Sachs-Wolfe (ISW) effect directly probes the dynamics of cosmic acceleration and the nature of dark energy. Detecting these weak, secondary temperature anisotropy signals of the CMB requires accurate…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-13 Mina Ghodsi Yengejeh , András Kovács , István Szapudi , István Csabai

We constrain plausible dark energy models, parametrized by multiple candidate equation of state, using the recently published Cosmic Microwave Background (CMB) temperature anisotropy data from Planck together with the WMAP-9 low-$\ell$…

Cosmology and Nongalactic Astrophysics · Physics 2015-04-22 Dhiraj Kumar Hazra , Subhabrata Majumdar , Supratik Pal , Sudhakar Panda , Anjan A. Sen

We study effects of possible tachyonic perturbations of dark energy on the CMB temperature anisotropy. Motivated by some models of phantom energy, we consider both Lorentz-invariant and Lorentz-violating dispersion relations for tachyonic…

Astrophysics · Physics 2010-04-30 M. V. Libanov , V. A. Rubakov , O. S. Sazhina , M. V. Sazhin

Most dark energy models have the $\Lambda$CDM as their limit, and if future observations constrain our universe to be close to $\Lambda$CDM Bayesian arguments about the evidence and the fine-tuning will have to be employed to discriminate…

Cosmology and Nongalactic Astrophysics · Physics 2018-11-27 Olga Avsajanishvili , Yiwen Huang , Lado Samushia , Tina Kahniashvili

Recent astronomical observations show that the universe may be anisotropic on large scales. The Union2 SnIa data hint that the universe has a preferred direction. If such a cosmological privileged axis indeed exists, one has to consider an…

General Relativity and Quantum Cosmology · Physics 2019-07-03 Amin Salehi , S. Aftabi

In this paper, we constrain dark energy models using a compendium of observations at low redshifts. We consider the dark energy as a barotropic fluid, with the equation of state a constant as well the case where dark energy equation of…

Cosmology and Nongalactic Astrophysics · Physics 2017-06-21 Ashutosh Tripathi , Archana Sangwan , H. K. Jassal

In this paper we have investigated the general form of viscous and non-viscous dark energy equation of state (EoS) parameter in the scope of anisotropic Bianchi type I space-time. We show that the presence of bulk viscosity causes…

General Relativity and Quantum Cosmology · Physics 2014-03-20 Hassan Amirhashchi , Anirudh Pradhan

The latest Baryon Acoustic Oscillation (BAO) measurements from the Dark Energy Spectroscopic Instrument (DESI) collaboration, when combined with Planck satellite Cosmic Microwave Background (CMB) data and Type Ia Supernovae, suggest a…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-09 William Giarè

We propose a new cosmological model that considers dark matter as a barotropic fluid with a constant equation of state parameter and interprets dark energy as the phenomenological emergent dark energy rather than a cosmological constant.…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-11 Jianqi Liu , Yanhong Yao , Yan Su , Junchao Wang , Jiawei Wu

We analyse pre-DESI clustering data using a dark energy equation of state $w(z)$ parametrised by $(w_0, w_a)$, finding a $2.8-3.9\sigma$ preference for evolving dark energy over the cosmological constant $\Lambda$ when combined with cosmic…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-16 Zhiyu Lu , Théo Simon , Pierre Zhang

We explores the Pantheon+SH0ES dataset to identify patterns that can discriminate between different cosmological models. We focus on determining whether the behaviour of dark energy is consistent with the standard $\Lambda$CDM model or…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-19 Simone Vilardi , Salvatore Capozziello , Massimo Brescia

Using current observations forecast type Ia supernovae (SNe Ia) Joint Lightcurve Analysis (JLA) and baryon acoustic oscillations (BAO), in this paper we investigate six bidimensional dark energy parameterisations in order to explore which…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-15 Celia Escamilla-Rivera

In this work, we study two scalar field driven dark energy models characterized by the axion potential and the inverse power law potential, each coupled to dark matter through a momentum exchange interaction. By formulating the dynamics as…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-27 Prasanta Sahoo , Nandan Roy , Himadri Shekhar Mondal