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Dark energy (DE) plays an important role in the expansion history of our universe. But we only got limited knowledge about its nature and properties after decades of study.In most numerical researches, DE is usually considered as a…

Cosmology and Nongalactic Astrophysics · Physics 2021-08-02 Ke Wang , Lu Chen

Dark energy might interact with cold dark matter in a direct, nongravitational way. However, the usual interacting dark energy models (with constant $w$) suffer from some catastrophic difficulties. For example, the $Q\propto\rho_{\rm c}$…

Cosmology and Nongalactic Astrophysics · Physics 2014-04-28 Yun-He Li , Xin Zhang

This study investigates the potential of a cosmological model termed $\Lambda w$DM, in which a cosmological constant play the role of dark energy and dark matter is barotropic and has a constant equation of state parameter ($w_{\rm dm}$),…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-02 Yan-Hong Yao , Jian-Qi Liu

Dark Energy Spectroscopic Instrument (DESI) observations, when combined with Cosmic Microwave Background (CMB) and Type Ia supernovae (SNe), have led to statistically significant dynamical dark energy (DDE) claims. In this letter we…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-28 Eoin Ó Colgáin , M. M. Sheikh-Jabbari

A key attribute of dark energy is the equation of state parameter $w={\rm pressure}/{\rm energy~density}$, and this has been recently measured observationally, giving values close to $-1$. In this paper we calculate the $w$ parameter…

General Relativity and Quantum Cosmology · Physics 2024-09-17 Stephen L. Adler

We investigate the impacts of dark energy on constraining massive (active/sterile) neutrinos in interacting dark energy (IDE) models by using the current observations. We employ two typical IDE models, the interacting $w$ cold dark matter…

Cosmology and Nongalactic Astrophysics · Physics 2020-05-14 Lu Feng , Dong-Ze He , Hai-Li Li , Jing-Fei Zhang , Xin Zhang

Baryon acoustic oscillation measurements by the Dark Energy Spectroscopic Instrument (Data Release 1) have revealed exciting results that show evidence for dynamical dark energy at $\sim3\sigma$ when combined with cosmic microwave…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-30 Bikash R. Dinda , Roy Maartens

We investigate whether the recent DESI DR2 measurements provide or not evidences for dynamical dark energy by exploring the $\omega_0\omega_a$CDM model and its extensions with free $\sum m_{\nu}$ and $N_{\mathrm{eff}}$. Using a…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-25 Salvatore Capozziello , Himanshu Chaudhary , Tiberiu Harko , Ghulam Mustafa

Cosmological consequences of adding the Cold Dark Matter (CDM) to the exactly solvable stringy Dark Energy (DE) model are investigated. The model is motivated by the consideration of our Universe as a slowly decaying D3-brane. The decay of…

Astrophysics · Physics 2009-11-11 I. Ya. Aref'eva , A. S. Koshelev , S. Yu. Vernov

We consider the cosmological application of Lee-Wick theory where a field has a higher derivative kinetic operators. The higher derivative term can be eliminated by introducing a set of auxiliary fields. We investigate the cosmological…

Astrophysics · Physics 2008-12-08 Seokcheon Lee

New insights from the Dark Energy Spectroscopic Instrument (DESI) 2024 baryon acoustic oscillations (BAO) data, in conjunction with cosmic microwave background (CMB) and Type Ia supernova (SN) data, suggest that dark energy may not be a…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-06 Tian-Nuo Li , Yun-He Li , Guo-Hong Du , Peng-Ju Wu , Lu Feng , Jing-Fei Zhang , Xin Zhang

In this letter we argue that the CPL parameterisation for the dark energy equation of state is biased towards preferring such model over the constant $w$ while the latter bounds are still compatible with LCDM. For that we compare…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-27 Ziad Sakr

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

We have calculated constraints on the evolution of the equation of state of the dark energy, w(z), from a joint analysis of data from the cosmic microwave background, large scale structure and type-Ia supernovae. In order to probe the…

Astrophysics · Physics 2009-11-10 Steen Hannestad , Edvard Mortsell

A fundamental question in cosmology is whether dark energy evolves over time, a topic that has gained prominence since the discovery of cosmic acceleration. Recently, the DESI collaboration has reported increasing evidence for evolving dark…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-21 Deng Wang , David Mota

We investigate future constraints on early dark energy (EDE) achievable by the Planck and CMBPol experiments, including cosmic microwave background (CMB) lensing. For the dark energy, we include the possibility of clustering through a sound…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-01 Erminia Calabrese , Roland de Putter , Dragan Huterer , Eric V. Linder , Alessandro Melchiorri

We consider a generic description of interacting dynamical Dark Energy, characterized by an equation of state with a time dependent coefficient $w(t)$, and which may interact with both radiation and matter. Without referring to any…

General Relativity and Quantum Cosmology · Physics 2019-08-20 Marco Bonici , Nicola Maggiore

Measurements of time-delay cosmography of lensed quasars can provide an independent probe to explore the expansion history of the late-time Universe. In this paper, we employ the time-delay cosmography measurements from seven lenses (here…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-23 Ling-Feng Wang , Jie-Hao Zhang , Dong-Ze He , Jing-Fei Zhang , Xin Zhang

Axion-like early dark energy (EDE) as an extension to $\Lambda$CDM has been proposed as a possible solution to the 'Hubble tension'. We revisit this model using a new cosmic microwave background (CMB) temperature and polarization likelihood…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-02 George Efstathiou , Erik Rosenberg , Vivian Poulin

The Hubble ($H_0$) tension between direct measurements of the expansion rate and the prediction of the $\Lambda$CDM cosmological model calibrated on the Cosmic Microwave Background (CMB), is a strong motivation to explore alternative…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-12 Clément Stahl , Vivian Poulin , Benoit Famaey , Rodrigo Ibata