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相关论文: Crossing the Phantom Divide: Theoretical Implicati…

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In this paper, using and implementing a new line of sight CMB code, called CMBAns [1], that allows us to modify H(z) for any given feature at any redshift we study the effect of changes in the expansion history of the Universe on the CMB…

宇宙学与河外天体物理 · 物理学 2013-10-14 Santanu Das , Arman Shafieloo , Tarun Souradeep

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 ($w_{\rm dm}$),…

宇宙学与河外天体物理 · 物理学 2025-07-02 Yan-Hong Yao , Jian-Qi Liu

Early dark energy models, for which the contribution to the dark energy density at high redshifts is not negligible, influence the growth of cosmic structures and could leave observable signatures that are different from the standard…

宇宙学与河外天体物理 · 物理学 2009-04-01 Jun-Qing Xia , Matteo Viel

The main aim of this work is to use a model-independent approach, along with late-time observational probes, to reconstruct the dark energy (DE) equation of state $w_{\rm DE}(z)$. Our analysis showed that, for a late time universe, $w_{\rm…

宇宙学与河外天体物理 · 物理学 2025-01-23 Luis A. Escamilla , Supriya Pan , Eleonora Di Valentino , Andronikos Paliathanasis , J. Alberto Vázquez , Weiqiang Yang

We examine the validity of the $\Lambda$CDM model, and probe for the dynamics of dark energy using latest astronomical observations. Using the $Om(z)$ diagnosis, we find that different kinds of observational data are in tension within the…

宇宙学与河外天体物理 · 物理学 2017-06-14 Yuecheng Zhang , Hanyu Zhang , Dandan Wang , Yanghan Qi , Yuting Wang , Gong-Bo Zhao

A pressureless dark matter component fits well with several cosmological observations. However, there are indications that cold dark matter may encounter challenges in explaining observations at small scales, particularly at galactic…

宇宙学与河外天体物理 · 物理学 2025-04-17 Weiqiang Yang , Supriya Pan , Eleonora Di Valentino , Olga Mena , David F. Mota , Subenoy Chakraborty

We use the integrated Sachs-Wolfe (ISW) effect, by now detectable at $\sim 5\sigma$ within the context of $\Lambda{}$CDM cosmologies, to place strong constraints on dynamical dark energy theories. Working within an effective field theory…

宇宙学与河外天体物理 · 物理学 2024-07-18 Emeric Seraille , Johannes Noller , Blake D. Sherwin

In the current era of precision cosmology, the persistence of cosmological tensions, most notably the Hubble tension and the $S_8$ tension, challenges the standard $\Lambda$CDM model. To reconcile these tensions via late-time modifications…

宇宙学与河外天体物理 · 物理学 2025-02-18 Yashi Tiwari , Ujjwal Upadhyay , Rajeev Kumar Jain

The cosmic microwave background (CMB) and baryon acoustic oscillations (BAO) are two of the most robust observations in cosmology. The recent BAO measurements from the DESI collaboration have presented, for the first time, inconsistency…

宇宙学与河外天体物理 · 物理学 2025-05-13 Gen Ye , Matteo Martinelli , Bin Hu , Alessandra Silvestri

By combining data from seven cosmic microwave background experiments (including the latest WMAP results) with large scale structure data, the Hubble parameter measurement from the Hubble Space Telescope and luminosity measurements of Type…

天体物理学 · 物理学 2008-11-26 Alessandro Melchiorri , Laura Mersini , Carolina J. Odman , Mark Trodden

A new method to investigate a possible time-dependence of the dark energy equation of state $w$ is proposed. We apply this methodology to two of the most recent data sets of type Ia supernova (Union2 and SDSS) and the baryon acoustic…

宇宙学与河外天体物理 · 物理学 2015-05-27 E. M. Barboza , J. S. Alcaniz

In this work we propose a simple general parametrization scheme of the Hubble parameter for the scalar field dark energy models. In our approach it is possible to incorporate both the quintessence and phantom scalar field in a single…

宇宙学与河外天体物理 · 物理学 2022-01-25 Nandan Roy , Sangita Goswami , Sudipta Das

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…

宇宙学与河外天体物理 · 物理学 2025-10-13 Manisg Yadav , Archana Dixit , M. S. Barak , Anirudh Pradhan

We investigate models of dark energy with purely kinetic multiple k-essence sources that allow for the crossing of the phantom divide line, without violating the conditions of stability. It is known that with more than one kinetic k-field…

天体物理学 · 物理学 2010-04-28 Sourav Sur , Saurya Das

The interacting dark energy model could propose a effective way to avoid the coincidence problem. In this paper, dark energy is taken as a fluid with a constant equation of state parameter $w_x$. In a general gauge, we could obtain two sets…

宇宙学与河外天体物理 · 物理学 2014-04-10 Weiqiang Yang , Lixin Xu

We present a Bayesian comparative analysis of five cosmological models: $\Lambda$CDM, $w$CDM, $w_0w_a$CDM, $\phi$CDM (with scalar-field dark energy), and an interacting dark energy scenario (the $\xi$-index model), to investigate dark…

宇宙学与河外天体物理 · 物理学 2025-12-19 Zhuoming Zhang , Tengpeng Xu , Yun Chen

I review the observational prospects to constrain the equation of state parameter of dark energy and I discuss the potential of future imaging and redshift surveys. Bayesian model selection is used to address the question of the level of…

天体物理学 · 物理学 2007-05-23 Roberto Trotta

We establish constraints on $f(T)$ gravity by considering the possibility of a scenario that supports a phantom crossing of the equation of state parameter $\omega_{DE}$. After determining the viable parameter space of the model, while…

宇宙学与河外天体物理 · 物理学 2023-06-23 F. B. M. dos Santos

Properties of Braneworld models of dark energy are reviewed. Braneworld models admit the following interesting possibilities: (i) The effective equation of state can be w < -1 as well as w > -1. In the former case the expansion of the…

天体物理学 · 物理学 2007-05-23 Varun Sahni

Context. A comprehensive survey of Baryon Acoustic Oscillation (BAO) in the Large Scale Structure (LSS), in stratified data covering a finite redshift range is provided by the Dark Energy Spectroscopic Instrument (DESI). Extracting…

宇宙学与河外天体物理 · 物理学 2025-12-01 Maryam Aghaei Abchouyeh , Maurice H. P. M. van Putten