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Related papers: Probing a Steep EoS for Dark Energy with latest ob…

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We investigate the cosmological implications of a generalized total equation of state (EoS) model by constraining its parameters using observational datasets to effectively characterize the universe's expansion history and its dynamic…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-14 M. Koussour , S. Bekov , A. Syzdykova , S. Muminov , I. Ibragimov , J. Rayimbaev

Recently, there has been considerable debate regarding potential evidence for the dynamical nature of dark energy (DE), particularly in light of Baryon Acoustic Oscillations (BAO) measurements released by DESI survey. In this work, we…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-18 Mateus Scherer , Miguel A. Sabogal , Rafael C. Nunes , Antonio De Felice

We critically examine the state of current constraints on the dark energy (DE) equation of state (EoS) $w$. Our study is motivated by the observation that, while broadly consistent with the cosmological constant value $w=-1$, several…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-22 Luis A. Escamilla , William Giarè , Eleonora Di Valentino , Rafael C. Nunes , Sunny Vagnozzi

In this work we explore signatures of evolution for the dark energy density $X(z)=\rho_{de}(z)/\rho_{de}(0)$ using latest observations on SNIa and H(z). The models consist of parametrizations of the dark energy density and consequently a…

Cosmology and Nongalactic Astrophysics · Physics 2022-07-27 Daniela Grandon , Victor H. Cardenas

We present an updated reconstruction of the DE equation of state (EoS), $w(a)$, employing the newly released DESI DR2 Baryon Acoustic Oscillation data. This analysis constrains the cosmological scenarios influenced by different models…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-17 Saddam Hussain , Simran Arora , Anzhong Wang , Ben Rose

We explore the cosmological constraints on the parameter w_dm of the dark matter barotropic equation of state (EoS) to investigate the "warmness" of the dark matter fluid. The model is composed by the dark matter and dark energy fluids in…

Cosmology and Nongalactic Astrophysics · Physics 2012-11-21 Arturo Avelino , Norman Cruz , Ulises Nucamendi

The equation of state (EOS), $w(z)$, is the most important parameter of dark energy. We reconstruct the evolution of this EOS in a model-independent way using the latest cosmic microwave background (CMB) data from Planck and other…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 F. Y. Wang , Z. G. Dai

Since the late 1990's observations of type Ia Supernova, our universe is predicted to experience a late time cosmic acceleration. Theoretical support to this observation were intended to be built via proposition of a hypothetical fluid…

General Relativity and Quantum Cosmology · Physics 2020-08-10 Promila Biswas , Parthajit Roy , Ritabrata Biswas

Recent measurements of Baryon Acoustic Oscillations (BAO) and distance moduli from Type Ia supernovae suggest a preference for Dynamical Dark Energy (DDE) scenarios characterized by a time-varying equation of state (EoS). This focused…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-11 William Giarè , Tariq Mahassen , Eleonora Di Valentino , Supriya Pan

Recent Baryon Acoustic Oscillation (BAO) measurements released by DESI, when combined with Cosmic Microwave Background (CMB) data from Planck and two different samples of Type Ia supernovae (Pantheon-Plus and DESY5) reveal a preference for…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-11 William Giarè , Mahdi Najafi , Supriya Pan , Eleonora Di Valentino , Javad T. Firouzjaee

This study explores the possibility of a time-varying dark energy (DE) equation of state (EoS) deviating from -1. We employ a comprehensive dataset of usual astronomical probes (Type Ia supernovae, baryon acoustic oscillations, Big Bang…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-23 Mehdi Rezaei , Supriya Pan , Weiqiang Yang , David F. Mota

We revisit the theoretical priors used for inferring Dark Energy (DE) parameters. Any DE model must have some form of a tracker mechanism such that it behaved as matter or radiation in the past. Otherwise, the model is fine-tuned. We…

Cosmology and Nongalactic Astrophysics · Physics 2023-10-24 Ido Ben-Dayan , Utkarsh Kumar

In this study, we explore the impact of various combinations of CMB-independent datasets, including the recent DESI BAO measurements, on the equation of state (EoS) of dark energy and other cosmological parameters within the framework of…

Cosmology and Nongalactic Astrophysics · Physics 2025-10-13 Manisg Yadav , Archana Dixit , M. S. Barak , Anirudh Pradhan

Recently the Dark Energy Spectroscopic Instrument (DESI) provided constraints on the expansion history from their Data Release 2 (DR2). The DESI baryon acoustic oscillation (BAO) measurements are well described by a flat $\Lambda$CDM model,…

We study the evidence for dark energy (DE) evolution at low redshift, using baryonic acoustic oscillations (BAOs) from the DESI Early Data Release, Pantheon+ Type Ia supernovae (SNe-Ia), and redshift space distortions (RSDs) to constrain…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-30 Lili Orchard , Víctor H. Cárdenas

The equation of state (EOS) of the dark energy is the key parameter to study the nature of the dark energy from the observation. Though the dark energy is found to be well consistent with the cosmological constant with a constant EOS of…

Cosmology and Nongalactic Astrophysics · Physics 2015-09-24 Shi Qi

The latest findings from the DESI (Dark Energy Spectroscopic Instrument) data release 1 (DR1) [1], combined with data from the cosmic microwave background and supernovae, suggest a preference for dynamical dark energy over the cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-16 Nandan Roy

The behavior of the dark energy equation of state (EOS) is crucial in distinguishing different cosmological models. With a model independent approach, we constrain the possible evolution of the dark energy EOS. Gamma-ray bursts (GRBs) of…

Astrophysics · Physics 2008-12-20 Shi Qi , Fa-Yin Wang , Tan Lu

We adopt a model independent method to reconstruct the dark energy equation of state by analyzing 5 sets of SNe Ia data along with Baryon Acoustic Oscillation (BAO) and Observational Hubble Data (OHD). The SNe Ia data sets include the most…

Cosmology and Nongalactic Astrophysics · Physics 2011-03-15 Debabrata Adak , Abhijit Bandyopadhyay , Debasish Majumdar