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The thermodynamic and dynamical properties of a variable dark energy model with density scaling as rho_x \propto (1+z)^m, z being the redshift, are discussed following the outline of Jetzer et al. This kind of models are proven to lead to…

Cosmology and Nongalactic Astrophysics · Physics 2011-09-08 Philippe Jetzer , Crescenzo Tortora

I apply the modified spherical infall model to test the dependence of the shape of density profiles of dark matter halos on redshift. The model predicts that the density profile of a halo of a given mass steepens with time and its…

Astrophysics · Physics 2007-05-23 Ewa L. Lokas

In this paper, we analyze the dynamical evolution of quintessence dark energy induced by the collapse of dark matter halos. Different from other previous studies, we develop a numerical strategy which allows us to calculate the dark energy…

Cosmology and Nongalactic Astrophysics · Physics 2009-07-09 Qiao Wang , Zuhui Fan

In order to derive model-independent observational bounds on dark energy/modified gravity theories, a typical approach is to constrain parametrised models intended to capture the space of dark energy theories. Here we investigate in detail…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-03 Neel Shah , Kazuya Koyama , Johannes Noller

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 use the presently observed number density of large X-ray clusters and linear mass power spectra to constrain the shape parameter ($\Gamma$), the spectral index ($n$), the amplitude of matter density perturbations on the scale of $8…

Astrophysics · Physics 2010-12-13 Jiun-Huei Proty Wu

We examine the effects of possible phenomenological interactions between dark energy and dark matter on cosmological parameters and their efficiency in solving the coincidence problem. We work with two simple parameterizations of the…

Astrophysics · Physics 2009-06-23 Jian-Hua He , Bin Wang

We consider indirect detection signals of atomic dark matter, with a massive dark photon which mixes kinetically with hypercharge. In significant regions of parameter space, dark matter remains at least partially ionized today, and dark…

High Energy Physics - Phenomenology · Physics 2015-04-29 Lauren Pearce , Kalliopi Petraki , Alexander Kusenko

The idea of a negative-pressure dark energy component in the Universe which causes an accelerated expansion in the late Universe has deep implications in models of field theory and general relativity. In this article, we survey the evidence…

Cosmology and Nongalactic Astrophysics · Physics 2021-09-29 Arindam Mazumdar , Subhendra Mohanty , Priyank Parashari

We review dark energy models which can present non-negligible fluctuations on scales smaller than Hubble radius. Both linear and nonlinear evolutions of dark energy fluctuations are discussed. The linear evolution has a well-established…

Cosmology and Nongalactic Astrophysics · Physics 2022-04-27 Ronaldo C. Batista

We show that in clustering dark energy models the growth index of linear matter perturbations, $\gamma$, can be much lower than in $\Lambda$CDM or smooth quintessence models and present a strong variation with redshift. We find that the…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-08 Ronaldo C. Batista

A new method for measuring gravitational lensing with high redshift type Ia supernovae is investigated. The method utilizes correlations between foreground galaxies and supernova brightnesses to substantially reduce possible systematic…

Astrophysics · Physics 2017-03-22 R. Benton Metcalf

This article concerns the formation and structure of dark matter halos, including (1) their radial density profiles, (2) their abundance, and (3) their merger rates. The last topic may be relevant to the nature of the small, bright,…

Astrophysics · Physics 2007-05-23 J. R. Primack , J. S. Bullock , A. A. Klypin , A. V. Kravtsov

Annihilating dark matter (DM) models offer promising avenues for future DM detection, in particular via modification of astrophysical signals. However when modelling such potential signals at high redshift the emergence of both dark matter…

Cosmology and Nongalactic Astrophysics · Physics 2017-12-27 Sarah Schon , Katherine J. Mack , Stuart B. Wyithe

We study the impact of Early Dark Energy fluctuations in the linear and non-linear regimes of structure formation. In these models the energy density of dark energy is non-negligible at high redshifts and the fluctuations in the dark energy…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-14 R. C. Batista , F. Pace

Observations of high redshift type Ia supernovae (SNe) will enable us to probe the structure of galaxy halos and the composition of dark matter. The future prospects for this field are briefly discussed here. First the ability of SN…

Astrophysics · Physics 2007-05-23 R. Benton Metcalf

We study dark energy through the viewpoints of parametric and nonparametric analyses of late-time cosmological data. We consider four Hubble parameter priors reflecting the Hubble tension and make use of two phenomenological functions,…

Cosmology and Nongalactic Astrophysics · Physics 2022-04-27 Reginald Christian Bernardo , Daniela Grandón , Jackson Levi Said , Víctor H. Cárdenas

Observations of high redshift supernovae imply an accelerating Universe which can only be explained by an unusual energy component such as vacuum energy or quintessence. To assess the ability of current and future supernova data to…

Astrophysics · Physics 2009-11-06 Yun Wang , Peter M. Garnavich

We use numerical simulations of critically-closed cold dark matter (CDM) models to study the effects of numerical resolution on observable quantities. We study simulations with up to $256^3$ particles using the particle-mesh (PM) method and…

Astrophysics · Physics 2009-10-22 James M. Gelb , Edmund Bertschinger

Bulk dark energy properties are determined by the redshift evolution of its pressure-to-density ratio, $w_{de}(z)$. An experimental goal is to decide if the dark energy is dynamical, as in the quintessence (and phantom) models treated here.…

Cosmology and Nongalactic Astrophysics · Physics 2011-01-27 Zhiqi Huang , J. Richard Bond , Lev Kofman