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Related papers: Structural Limitations on Constraining the Time Ev…

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We study cosmological perturbations in a model of unified dark matter and dark energy with a sharp transition in the late-time universe. The dark sector is described by a dark fluid which evolves from an early stage at redshifts $z > z_C$…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-05 Rodrigo R. Cuzinatto , Léo G. Medeiros , Eduardo M. de Morais , Robert H. Brandenberger

We investigate the dynamical properties of dark energy through a detailed analysis of its equation of state parameter $w(z)$ as a function of redshift. We derive a general expression for $w(z)$ from the Friedmann-Lema\^itre-Robertson-Walker…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-29 J. W. Moffat , E. J. Thompson

We use astrophysical and atomic clock tests of the stability of the fine-structure constant $\alpha$, together with Type Ia supernova and Hubble parameter data, to constrain the simplest class of dynamical dark energy models where the same…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-12 C. J. A. P. Martins , A. M. M. Pinho

Reconstructed from lensing tomography, the evolution of the dark matter density field in the well-understood linear regime can provide model-independent constraints on the growth function of structure and the evolution of the dark energy…

Astrophysics · Physics 2008-11-26 Wayne Hu

We compute the number density of massive Black Holes (BHs) at the centre of galaxies at z=6 in different Dynamical Dark Energy (DDE) cosmologies, and compare it with existing observational lower limits, to derive constraints on the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Alessandra Lamastra , Nicola Menci , Fabrizio Fiore , Cinzia Di Porto , Luca Amendola

Astrophysical tests of the stability of fundamental couplings, such as the fine-structure constant $\alpha$, are becoming an increasingly powerful probe of new physics. Here we discuss how these measurements, combined with local atomic…

Cosmology and Nongalactic Astrophysics · Physics 2015-09-09 C. J. A. P. Martins , A. M. M. Pinho , R. F. C. Alves , M. Pino , C. I. S. A. Rocha , M. von Wietersheim

We investigate a link between the running of the fine structure constant $\alpha$ and a time evolving scalar dark energy field. Employing a versatile parameterization for the equation of state, we exhaustively cover the space of dark energy…

Astrophysics · Physics 2009-11-10 Michael Doran

We apply a parameterization-independent approach to fitting the dark energy equation-of-state (EOS). Utilizing the latest type Ia supernova data, combined with results from the cosmic microwave background and baryon acoustic oscillations,…

Astrophysics · Physics 2008-11-26 Scott Sullivan , Asantha Cooray , Daniel E. Holz

The coupling between the dark components provides a new approach to mitigate the coincidence problem of cosmological standard model. In this paper, dark energy is treated as a fluid with a constant equation of state, whose coupling with…

Cosmology and Nongalactic Astrophysics · Physics 2014-08-18 Weiqiang Yang , Lixin Xu

The equation of state characterizing the dark energy component is constrained by combining Chandra observations of the X-ray luminosity of galaxy clusters with independent measurements of the baryonic matter density and the latest…

Astrophysics · Physics 2008-11-26 J. A. S. Lima , J. V. Cunha , J. S. Alcaniz

We study the sensitivity of weak lensing by large scale structures to the evolution of dark energy. We explore a 2-parameters model of dark energy evolution, inspired by tracking quintessence models. To this end, we compute the likelihood…

Astrophysics · Physics 2008-11-26 Karim Benabed , Ludovic Van Waerbeke

In this work we have used the recent cosmic chronometers data along with the latest estimation of the local Hubble parameter value, $H_0$ at 2.4\% precision as well as the standard dark energy probes, such as the Supernovae Type Ia, baryon…

Cosmology and Nongalactic Astrophysics · Physics 2017-08-02 Weiqiang Yang , Narayan Banerjee , Supriya Pan

The next generation of space-based galaxy surveys are expected to measure the growth rate of structure to about a percent level over a range of redshifts. The rate of growth of structure as a function of redshift depends on the behaviour of…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-20 Anatoly Pavlov , Lado Samushia , Bharat Ratra

In this paper we analyze the constraints on the property of dark energy from cosmological observations. Together with SNe Ia Gold sample, WMAP, SDSS and 2dFGRS data, we include 69 long Gamma-Ray Bursts (GRBs) data in our study and perform…

Astrophysics · Physics 2008-11-26 Hong Li , Meng Su , Zuhui Fan , Zigao Dai , Xinmin Zhang

We present an Effective Field Theory based reconstruction of quintessence models of dark energy directly from cosmological data. We show that current cosmological data possess enough constraining power to test several quintessence model…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-26 Minsu Park , Marco Raveri , Bhuvnesh Jain

Current observational bounds on dark energy depend on assumptions about the curvature of the universe. We present a simple and efficient method for incorporating constraints from CMB anisotropy data, and use it to derive constraints on…

Astrophysics · Physics 2010-04-06 Yun Wang , Pia Mukherjee

We present a framework that combines physics-informed neural networks (PINNs) with Markov Chain Monte Carlo (MCMC) inference to constrain dynamical dark energy models using the Pantheon+ Type Ia supernova compilation. First, we train a…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-19 Anshul Verma , Shashwat Sourav , Pavan K. Aluri , David F. Mota

We perform a cosmological parameter analysis of the 75 square degree CTIO lensing survey in conjunction with CMB and Type Ia supernovae data. For Lambda CDM cosmologies, we find that the amplitude of the power spectrum at low redshift is…

Astrophysics · Physics 2008-11-26 Mike Jarvis , Bhuvnesh Jain , Gary Bernstein , Derek Dolney

We study structure formation in alternative cosmological models constrained by background observations, including $\Lambda$CDM, wCDM, the Chevallier-Polarski-Linder parametrisation and a flexible Chebyshev expansion of the dark energy…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-15 Greco A. Peña , Mario H. Amante , Javier Chagoya , Cristian Barrera-Hinojosa , C. Ortiz , Graeme Candlish

The equation of state of the hypothetical dark energy component, which constitutes about two thirds of the critical density of the universe, may be very different from that of a cosmological constant. Employing a phenomenological model, we…

Astrophysics · Physics 2010-12-09 Wolung Lee , Kin-Wang Ng