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Related papers: Reconstructing quintom from WMAP 5-year observatio…

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Motivated by the recent work of Zhang and Chen \cite{bin}, we generalize their work to the non-minimally coupled case. We consider a quintom model of dark energy with a single scalar field $T$ given by a Lagrangian which inspired by…

High Energy Physics - Theory · Physics 2011-08-04 M R Setare , J Sadeghi , A R Amani

In this paper, we employ two model-independent approaches, including redshift binning method and polynomial interpolation method, to reconstruct dark energy (DE) equation of state (EoS) $w(z)$ and DE density function $f(z)$. Our analysis…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-18 Jun-Xian Li , Shuang Wang

Using the low limit of cosmic ages from globular cluster and the white dwarfs: $t_0 > 12$Gyr, together with recent new high redshift supernova observations from the HST/GOODS program and previous supernova data, we give a considerable…

Astrophysics · Physics 2011-05-05 Bo Feng , Xiulian Wang , Xinmin Zhang

Time-varying dark energy is often modeled in observational analyses through generic parameterizations of its equation of state $w(z)$, which typically use two free parameters $\{w_0, w_a\}$ to span a broad range of behaviors as a function…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-27 David Shlivko , Paul J. Steinhardt , Charles L. Steinhardt

Within the framework of FRW cosmology, we study the QCD modified ghost scalar field models of dark energy in the presence of both interaction and viscosity. For a spatially non-flat FRW universe containing modified ghost dark energy (MGDE)…

General Physics · Physics 2013-04-30 K. Karami , S. Asadzadeh , M. Mousivand , Z. Safari

(abridged) We used a suite of numerical cosmological simulations in order to investigate the effect of gas cooling and star formation on the large scale matter distribution. The simulations follow the formation of cosmic structures in five…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 C. Fedeli , K. Dolag , L. Moscardini

Regarding the Veneziano ghost of QCD and its generalized form, we consider a Friedmann-Robertson-Walker (FRW) universe filled by a pressureless matter and a dark energy component interacting with each other through a mutual sign-changeable…

General Relativity and Quantum Cosmology · Physics 2018-04-10 M. Abdollahi Zadeh , A. Sheykhi , H. Moradpour

The current paper provides a comprehensive examination of a dark energy cosmological model in the classical regime, in which a generic scalar field is regarded as a dark energy source. Einstein's field equations are solved in model…

General Relativity and Quantum Cosmology · Physics 2022-09-07 Ritika Nagpal , Shibesh Kumar Jas Pacif , Abhishek Parida

The generalized Chaplygin gas, characterized by the equation of state $p=-\mathcal{A}/\rho^{\alpha}$, has been considered as a model for dark energy due its dark-energy-like evolution at late times. When dissipative processes are taken…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Norman Cruz , Samuel Lepe , Francisco Pena

In this paper, we combine the the latest observational data, including the WMAP five-year data (WMAP5), the baryon acoustic oscillations (BAO) and type Ia supernovae (SN) "union" compilation, and use the Markov Chain Monte Carlo method to…

Cosmology and Nongalactic Astrophysics · Physics 2010-05-11 Hong Li , Jun-Qing Xia

Motivated by the recent Dark Energy Spectroscopic Instrument (DESI) DR2 preference for dynamical dark energy, we study interacting dark energy models in which a canonical quintessence field couples to cold dark matter through a…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-20 Stefan Antusch , Stephen F. King , Xin Wang

I calculate a hybrid cross-power spectrum estimator from the WMAP 5-year CMB temperature maps, discuss the goodness of fit, and then constrain cosmological parameters. The spectrum and results are generally consistent with previous results,…

Astrophysics · Physics 2017-08-07 Antony Lewis

The generalized Chaplygin gas (GCG) model explains the recent accelerated expansion of the Universe via an exotic background fluid whose equation of state is given by p=-A/\rho^\alpha, where A is a positive constant and 0<\alpha\le 1. The…

Astrophysics · Physics 2015-06-24 M. C. Bento , O. Bertolami , A. A. Sen

We perform an empirical consistency test of General Relativity/dark energy by disentangling expansion history and growth of structure constraints. We replace each late-universe parameter that describes the behavior of dark energy with two…

Cosmology and Nongalactic Astrophysics · Physics 2016-02-25 José Luis Bernal , Licia Verde , Antonio J. Cuesta

In this brief review, we examine the theoretical consistency and viability of phantom dark energy. Almost all data sets from cosmological probes are compatible with dark energy of the phantom variety (i.e., equation-of-state parameter…

Cosmology and Nongalactic Astrophysics · Physics 2017-09-26 Kevin J. Ludwick

We investigate quintom evolution in power-law potentials. We extract the early-time, tracker solutions, under the assumption of matter domination. Additionally, we derive analytical solutions at intermediate times, that is at low redshifts,…

Cosmology and Nongalactic Astrophysics · Physics 2011-05-27 Emmanuel N. Saridakis

Combined measurements of Baryon Acoustic Oscillations (BAO) from the Dark Energy Spectroscopic Survey (DESI), the Cosmic Microwave Background (CMB) and Type Ia Supernovae (SN Ia), have recently challenged the $\Lambda$-Cold Dark Matter…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-10 Rayff de Souza , Agripino Sousa-Neto , Javier E. González , Jailson Alcaniz

The primordial curvature fluctuation spectrum is reconstructed by the cosmic inversion method using the five-year WMAP data of the cosmic microwave background temperature anisotropy. We apply the covariance matrix analysis and decompose the…

Astrophysics · Physics 2008-12-30 Ryo Nagata , Jun'ichi Yokoyama

Understanding the origin of the accelerated expansion of the Universe poses one of the greatest challenges in physics today. Lacking a compelling fundamental theory to test, observational efforts are targeted at a better characterization of…

Cosmology and Nongalactic Astrophysics · Physics 2010-12-28 Tracy Holsclaw , Ujjaini Alam , Bruno Sanso , Herbert Lee , Katrin Heitmann , Salman Habib , David Higdon

New constraints on the expansion rate of the Universe seem to favor evolving dark energy in the form of thawing quintessence models, i.e., models for which a canonical, minimally coupled scalar field has, at late times, begun to evolve away…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-06 William J. Wolf , Carlos García-García , Deaglan J. Bartlett , Pedro G. Ferreira