English
Related papers

Related papers: The velocity-density relation in the spherical mod…

200 papers

We consider a two-dimensional Coulomb gas of positive and negative pointlike unit charges interacting via a logarithmic potential. The density (rather than the charge) correlation functions are studied. In the bulk, the form-factor theory…

Statistical Mechanics · Physics 2007-05-23 L. Šamaj , B. Jancovici

We present cosmological parameter constraints from the SFI++ galaxy peculiar velocity survey, the largest galaxy peculiar velocity sample to date. The analysis is performed by using the gridding method developed in Abate et al. (2008). We…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Alexandra Abate , Pirin Erdogdu

Courteau et al. (2007a) reported on the dependence of the ratio of a galaxy's maximum circular velocity, Vcirc, to its central velocity dispersion, sigma0, on morphology, or equivalently total light concentration. This Vcirc-sigma0…

Astrophysics · Physics 2009-11-13 Stephane Courteau , Michael McDonald , Lawrence M. Widrow

We investigate the running cosmological constant model with dark energy linearly proportional to the Hubble parameter, $\Lambda = \sigma H + \Lambda_0$, in which the $\Lambda$CDM limit is recovered by taking $\sigma=0$. We derive the linear…

Cosmology and Nongalactic Astrophysics · Physics 2016-07-22 Chao-Qiang Geng , Chung-Chi Lee , Kaituo Zhang

We present a tomographic cosmic shear study from the Deep Lens Survey (DLS), which, providing a limiting magnitude r_{lim}~27 (5 sigma), is designed as a pre-cursor Large Synoptic Survey Telescope (LSST) survey with an emphasis on depth.…

Cosmology and Nongalactic Astrophysics · Physics 2016-06-22 M. James Jee , J. Anthony Tyson , Stefan Hilbert , Michael D. Schneider , Samuel Schmidt , David Wittman

We review observational tests for the homogeneity of the Universe on large scales. Redshift and peculiar velocity surveys, radio sources, the X-Ray Background, the Lyman-$\alpha$ forest and the Cosmic Microwave Background are used to set…

Astrophysics · Physics 2007-05-23 Ofer Lahav

In the context of a homogeneous and isotropic universe, we consider the degeneracy condition at the background level between two scenarios in which processes out of equilibrium are possible; this consideration allows us to deviate from the…

General Relativity and Quantum Cosmology · Physics 2025-03-05 Gilberto Aguilar-Pérez , Ana A. Avilez-López , Miguel Cruz

Cosmological models with different types of Dark Energy are becoming viable alternatives for standard models with the cosmological constant. Yet, such models are more difficult to analyze and to simulate. We present analytical…

Astrophysics · Physics 2009-11-07 R. Mainini , A. V. Maccio' , S. A. Bonometto , A. Klypin

The distance-redshift relation depends on the amount of matter of each type in the universe. Measurements at different redshifts constrain differing combinations of these matter densities and thus may be used in combination to constrain…

Astrophysics · Physics 2009-08-18 Martin White

The fundamental constants of electromagnetism, gravity and quantum mechanics can be related empirically by the numerical approximation $\ln(V_e/V_P)\approx \alpha^{-1}$, where $\alpha$ is the low energy value of the electromagnetic fine…

General Physics · Physics 2018-01-31 L. Eaves

We investigate the connection between collisionless equilibria and the phase-space relation between density $\rho$ and velocity dispersion $\sigma$ found in simulations of dark matter halo formation, $F=\psd \propto r^{-\alpha}$.…

Astrophysics · Physics 2009-11-13 Eric I. Barnes , Liliya L. R. Williams , Arif Babul , Julianne J. Dalcanton

The power spectrum of mass density fluctuations is evaluated from the Mark III and the SFI catalogs of peculiar velocities by a maximum likelihood analysis, using parametric models for the power spectrum and for the errors. The applications…

Astrophysics · Physics 2007-05-23 Idit Zehavi , Avishai Dekel

During the past fifteen years, inhomogeneous cosmological models have been put forward to explain the observed dimming of the SNIa luminosity without resorting to dark energy. The simplest models are the spherically symmetric…

Cosmology and Nongalactic Astrophysics · Physics 2012-06-29 Marie-Noëlle Célérier

The two-point statistics of the cosmic velocity field, measured from galaxy peculiar velocity (PV) surveys, can be used as a dynamical probe to constrain the growth rate of large-scale structures in the universe. Most works use the…

Cosmology and Nongalactic Astrophysics · Physics 2024-03-07 Motonari Tonegawa , Stephen Appleby , Changbom Park , Sungwook E. Hong , Juhan Kim

Astronomical measurements of the Omegas for mass density, cosmological constant lambda and curvature k are shown to be sufficient to produce a unique and detailed cosmological model describing dark energy influences based on the Friedman…

General Physics · Physics 2010-01-14 James G. Gilson

We present a set of cosmological variables, called "supercomoving variables," which are particularly useful for describing the gas dynamics of cosmic structure formation. For ideal gas with gamma=5/3, the supercomoving position, velocity,…

Astrophysics · Physics 2009-10-30 Hugo Martel , Paul R. Shapiro

We study the evolution of the configuration entropy for different combinations of $\Omega_{m0}$ and $\Omega_{\Lambda0}$ in the flat $\Lambda$CDM universe and find that the cosmological constant plays a decisive role in controlling the…

Cosmology and Nongalactic Astrophysics · Physics 2019-03-06 Biswajit Pandey , Biswajit Das

(abridged) We estimate the cluster-galaxy cross-correlation function (Xi_cg), from the APM galaxy and galaxy cluster surveys, both in real space from the inversion of projected statistics and in redshift space using the galaxy and cluster…

Astrophysics · Physics 2009-10-30 Rupert Croft , Gavin Dalton , George Efstathiou

Brans-Dicke (BD) cosmology is reconsidered from an approach in which the model can be formulated in $\Lambda$CDM form, but at the expense of replacing the rigid cosmological constant $\Lambda$ with a dynamical quasivacuum component which…

General Relativity and Quantum Cosmology · Physics 2018-11-29 Javier de Cruz Perez , Joan Sola

One of the greatest challenges in cosmology today is to determine the nature of dark energy, the source of the observed present acceleration of the universe. High precision experiments are being developed to reduce the uncertainties in the…

Astrophysics · Physics 2007-05-23 Reuven Opher , Ana Pelinson