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Related papers: Testing an oscillatory behavior of dark energy

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Oscillations of the $F(R)$ dark energy around the phantom divide line, $\omega_{DE}=-1$, both during the matter era and also in the de Sitter epoch are investigated. The analysis during the de Sitter epoch is revisited by expanding the…

General Relativity and Quantum Cosmology · Physics 2015-05-30 E. Elizalde , S. D. Odintsov , L. Sebastiani , S. Zerbini

An anti-de Sitter vacuum, corresponding to a negative cosmological constant (NCC), might coexist with one evolving positive dark energy component at low redshift and is hinted by the latest DESI observations. In this paper, we use two…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-13 Hao Wang , Yun-Song Piao

We reconstruct the equation of state $w(z)$ of dark energy (DE) using a recently released data set containing 172 type Ia supernovae without assuming the prior $w(z) \geq -1$ (in contrast to previous studies). We find that dark energy…

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

We study the late-time evolution of the Universe where dark energy (DE) is presented by a barotropic fluid on top of cold dark matter (CDM). We also take into account the radiation content of the Universe. Here by the late stage of the…

General Relativity and Quantum Cosmology · Physics 2015-07-24 Ozgur Akarsu , Mariam Bouhmadi-López , Maxim Brilenkov , Ruslan Brilenkov , Maxim Eingorn , Alexander Zhuk

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

While cold dark matter is widely supported by a range of cosmological observations, it encounters several difficulties at smaller scales. These issues have prompted the investigation of various alternative dark matter candidates, leaving…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-23 Jian-Qi Liu , Yan-Hong Yao , Yan Su , Jia-Wei Wu

We investigate potential deviations from cold dark matter (CDM) using the latest Baryon Acoustic Oscillations (BAO) measurements from the Dark Energy Spectroscopic Instrument (DESI). Analyzing DESI data alone constrains the dark matter…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-22 Utkarsh Kumar , Abhijith Ajith , Amresh Verma

We explore an interacting dark matter (DM)-dark energy (DE) framework that naturally yields an effective dynamical DE equation of state crossing the phantom barrier at early times, as indicated by recent DESI data, while also accounting for…

High Energy Physics - Phenomenology · Physics 2026-01-07 Basabendu Barman , Sudhakantha Girmohanta

While there is plentiful evidence in all fronts of experimental cosmology for the existence of a non-vanishing dark energy (DE) density \rho_D in the Universe, we are still far away from having a fundamental understanding of its ultimate…

Astrophysics · Physics 2011-07-19 Javier Grande , Ana Pelinson , Joan Sola

Neutrinos and dark energy (DE) have entered a new era of investigation, as the latest DESI baryon acoustic oscillation measurements tighten the constraints on the neutrino mass and suggest that DE may be dynamical rather than a cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2025-10-31 Guo-Hong Du , Tian-Nuo Li , Peng-Ju Wu , Jing-Fei Zhang , Xin Zhang

Dynamical dark energy has gained renewed interest due to recent theoretical and observational developments. In the present paper, we focus on a string-motivated dark energy set-up, and perform a detailed cosmological analysis of exponential…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-04 Sukannya Bhattacharya , Giulia Borghetto , Ameek Malhotra , Susha Parameswaran , Gianmassimo Tasinato , Ivonne Zavala

Early data from the James Webb Space Telescope (JWST) has uncovered the existence of a surprisingly abundant population of very massive galaxies at extremely high redshift, which are hard to accommodate within the standard $\Lambda$CDM…

Cosmology and Nongalactic Astrophysics · Physics 2024-01-25 Shahnawaz A. Adil , Upala Mukhopadhyay , Anjan A. Sen , Sunny Vagnozzi

The DESI Collaboration reports a significant preference for a dynamic dark energy model ($w_0w_a$CDM) over the cosmological constant ($\Lambda$CDM) when their data are combined with other frontier cosmological probes. We present a direct…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-13 Dily Duan Yi Ong , David Yallup , Will Handley

We outline a dynamical dark energy scenario whose signatures may be simultaneously tested by astronomical observations and laboratory experiments. The dark energy is a field with slightly sub-gravitational couplings to matter, a logarithmic…

Astrophysics · Physics 2009-06-23 Nemanja Kaloper

Constraining simultaneously the Dark Energy(DE) equation of state and the curvature of the Universe is difficult due to strong degeneracies. To circumvent this problem when analyzing data it is usual to assume flatness to constrain DE, or…

Astrophysics · Physics 2009-06-23 J. -M. Virey , D. Talon-Esmieu , A. Ealet , P. Taxil , A. Tilquin

Recent observations from the DESI survey have reignited the debate on the true nature of dark energy, challenging the standard model of cosmology. The results suggest a preference for dynamical dark energy rather than a constant. Several…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-28 Ramanpreet Singh , Athul CN , H. K. Jassal

In this study, we use a flexible parametrization of the equation of state of dark energy to explore its possible evolution with datasets from the Dark Energy Spectroscopic Instrument (DESI), Planck cosmic microwave background, and either…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-14 Ryan E. Keeley , Kevork N. Abazajian , Manoj Kaplinghat , Arman Shafieloo

If CDM particles decay and their lifetime is comparable to the age of the Universe, they can modify its equation of state. By comparing the results of numerical simulations with high redshift SN-Ia observations we show that this hypothesis…

Astrophysics · Physics 2007-05-23 Houri Ziaeepour

Some issues of the cosmological constant or dark energy are briefly reviewed. There are an increasing number of observations that constrain the equation of state of dark energy more stringently and favor the time-independent cosmological…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Jun'ichi Yokoyama

Accurate predictions on non--linear power spectra, at various redshift z, will be a basic tool to interpret cosmological data from next generation mass probes, so obtaining key information on Dark Energy nature. This calls for high…

Astrophysics · Physics 2011-03-15 Luciano Casarini , Andrea V. Maccio' , Silvio A. Bonometto
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