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Related papers: Clustering, Angular Size and Dark Energy

200 papers

Two forms are suggested for the energy-momentum source term associated with an aggregate of dark matter (with the properties described in Paper I). Both have large pressure-like components which dominate the density terms. Using one form a…

General Relativity and Quantum Cosmology · Physics 2020-01-20 H. L. Helfer

(abridged) A wide-field galaxy redshift survey allows one to probe galaxy clustering at largest spatial scales, which carries an invaluable information on horizon-scale physics complementarily to the cosmic microwave background (CMB).…

Astrophysics · Physics 2009-11-11 Masahiro Takada

We present constraints on the mean dark energy density, Omega_X and dark energy equation of state parameter, w_X, based on Chandra measurements of the X-ray gas mass fraction in 26 X-ray luminous, dynamically relaxed galaxy clusters…

Astrophysics · Physics 2008-11-26 S. W. Allen , R. W. Schmidt , H. Ebeling , A. C. Fabian , L. van Speybroeck

We study the dipole for a redshift sample of Abell/ACO clusters. To elucidate the constraints it places on dark matter models, we use numerical simulations based on the Zel'dovich approximation. We run 20 realizations of each of six…

Astrophysics · Physics 2015-06-24 P. Tini Brunozzi , S. Borgani , M. Plionis , L. Moscardini , P. Coles

We consider a recently proposed model in which dark matter interacts with a thermal background of dark radiation. Dark radiation consists of relativistic degrees of freedom which allow larger values of the expansion rate of the universe…

Cosmology and Nongalactic Astrophysics · Physics 2018-01-24 Manuel A. Buen-Abad , Martin Schmaltz , Julien Lesgourgues , Thejs Brinckmann

It has been widely shown that the cosmological parameters and dark energy can be constrained by using data from type-Ia supernovae (SNe Ia), the cosmic microwave background (CMB) anisotropy, the baryon acoustic oscillation (BAO) peak from…

Astrophysics · Physics 2009-06-23 F. Y. Wang , Z. G. Dai , Zong-Hong Zhu

When using distance measurements to probe spatial curvature, the geometric degeneracy between curvature and dark energy in the distance-redshift relation typically requires either making strong assumptions about the dark energy evolution or…

Cosmology and Nongalactic Astrophysics · Physics 2009-12-14 Michael J. Mortonson

Using recent measurements of angular size of high-z milliarcsecond compact radio sources compiled by Gurvits, Kellermann and Frey (1999) and X-ray gas mass fraction of galaxy clusters published by Allen et al. (2002,2003), we explore their…

Astrophysics · Physics 2009-11-10 Zong-Hong Zhu , Masa-Katsu Fujimoto , Xiang-Tao He

We constrain the dark energy equation of state parameter, $w$, using the power spectrum of the thermal Sunyaev-Zeldovich (tSZ) effect. We improve upon previous analyses by taking into account the trispectrum in the covariance matrix and…

Cosmology and Nongalactic Astrophysics · Physics 2018-04-11 Boris Bolliet , Barbara Comis , Eiichiro Komatsu , Juan Francisco Macías-Pérez

I present an analysis of the density shapes of dark matter halos in LCDM and LWDM cosmologies. The main results are derived from a statistical sample of galaxy-mass halos drawn from a high resolution LCDM N-body simulation. Halo shapes show…

Astrophysics · Physics 2017-08-23 James S. Bullock

In this letter, we report precise and robust observational constraints on dark matter-dark energy scattering cross section, using the latest data from cosmic microwave background (CMB) Planck temperature and polarization, baryon acoustic…

Cosmology and Nongalactic Astrophysics · Physics 2017-11-06 Suresh Kumar , Rafael C. Nunes

I consider some of the issues we face in trying to understand dark energy. Huge fluctuations in the unknown dark energy equation of state can be hidden in distance data, so I argue that model-independent tests which signal if the…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Chris Clarkson

Large SZ selected galaxy cluster surveys are beginning imminently. We compare the dependence of the galaxy cluster angular power spectrum on cosmological parameters, different modeling assumptions and statistical observational errors. We…

Astrophysics · Physics 2009-11-10 J. D. Cohn , Kenji Kadota

The APM Galaxy Survey maps the angular positions of more than one million galaxies to $b_{J} = 20$, covering a volume comparable to the forthcoming Sloan Digital Sky Survey. A numerical algorithm has been developed to estimate the power…

Astrophysics · Physics 2007-05-23 C. M. Baugh , E. Gaztanaga

We put constraints on dark energy properties using the PADE parameterisation, and compare it to the same constraints using Chevalier-Polarski-Linder (CPL) and $\Lambda$CDM, at both the background and the perturbation levels. The dark energy…

Cosmology and Nongalactic Astrophysics · Physics 2017-06-09 Mehdi Rezaei , Mohammad Malekjani , Spyros Basilakos , Ahmad Mehrabi , David F. Mota

We consider a model-independent approach to constrain the equivalence redshift, $z_{eq}$, at which dark energy and the total matter (cold dark matter and baryonic) equate their magnitudes. To this aim, in the context of a homogeneous and…

Cosmology and Nongalactic Astrophysics · Physics 2023-08-31 Anna Chiara Alfano , Carlo Cafaro , Salvatore Capozziello , Orlando Luongo

We investigate how cluster morphology is affected by the cosmological constant in low-density universes. Using high-resolution cosmological N-body/SPH simulations of flat (\Omega_0 = 0.3, \lambda_0 = 0.7, \Lambda CDM) and open (\Omega_0 =…

Astrophysics · Physics 2009-11-07 Tamon Suwa , Asao Habe , Kohji Yoshikawa , Takashi Okamoto

In these Lectures I review possible constraints on particle physics models, obtained by means of combining the results of collider measurements with astrophysical data. I emphasize the theoretical-model dependence of these results. I…

High Energy Physics - Phenomenology · Physics 2017-08-23 Nikolaos E. Mavromatos

Modifications in Friedmann-Lemaitre-Robertson-Walker (FLRW) Hubble diagrams caused by mass density inhomogeneities are used to illustrate possible effects on a determination of the mass parameter $\Omega_m$ and the cosmological constant…

Astrophysics · Physics 2007-05-23 R. Kantowski