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Velocity fields can be reconstructed at cosmological scales from their influence on the correlation between the cosmic microwave background and large-scale structure. Effects that induce such correlations include the kinetic Sunyaev…

Cosmology and Nongalactic Astrophysics · Physics 2021-10-28 Selim C. Hotinli , Kendrick M. Smith , Mathew S. Madhavacheril , Marc Kamionkowski

Among the suggested solutions to the cosmological constant problem, we find the idea of a dynamic vacuum, with an energy density decaying with the universe expansion. We investigate the possibility of a variation in the gravitational…

General Relativity and Quantum Cosmology · Physics 2011-08-17 Saulo Carneiro

The underlying geometri of spacetime algebra allows one to derive a force by contracting the relativistic generalization of angular momentum, M, with the mass-current, mw, where w is a proper 4-vector velocity. By applying this force to a…

General Relativity and Quantum Cosmology · Physics 2021-06-17 Steen H. Hansen

We investigate some possible relations between physical observables and estimate the "cosmic variance" which affects these measurements. We focus on redshift and angular-distance and we discuss the difference in considering the redshift as…

Cosmology and Nongalactic Astrophysics · Physics 2018-06-26 Giuseppe Fanizza

When the cosmological "constant" is derived from modern five-dimensional relativity, exact solutions imply that for small systems it scales in proportion to the square of the mass. However, a duality transformation implies that for large…

General Physics · Physics 2014-02-05 Paul S. Wesson , James M. Overduin

The evolution of probability distribution functions (PDFs) of continuous density, velocity and velocity derivatives ( deformation tensor) fields in the theory of cosmological gravitational instability are considered. We show that in the…

Astrophysics · Physics 2007-05-23 Lev Kofman

Aims. We present an analysis of 37 high-quality extended rotation curves that highlights the existence of a new discrepancy (or a new aspect of an old discrepancy) between the density profiles predicted by the Lambda Cold Dark Matter…

Astrophysics · Physics 2008-11-26 Gianfranco Gentile , Chiara Tonini , Paolo Salucci

An approximate statistical description of the formation and evolution of structure of the universe based on the Zel'dovich theory of gravitational instability is proposed. It is found that the evolution of DM structure shows features of…

Astrophysics · Physics 2009-10-31 M. Demianski , A. Doroshkevich

This article reviews the concept of Lorentz invariant relative velocity that is often misunderstood or unknown in high energy physics literature. The properties of the relative velocity allow to formulate the invariant flux and cross…

High Energy Physics - Phenomenology · Physics 2017-02-08 Mirco Cannoni

We compare relativistic approximation methods, which describe gravitational instability in the expanding universe, in a spherically symmetric model. Linear perturbation theory, second-order perturbation theory, relativistic Zel'dovich…

Astrophysics · Physics 2014-10-13 Masaaki Morita , Kouji Nakamura , Masumi Kasai

A reconstruction of modified gravity is proposed by establishing a correspondence between the effective density of the modified gravity and the holographic density. The non-homogeneous term in the modified Friedmann equation, generated by…

General Relativity and Quantum Cosmology · Physics 2019-02-20 L. N. Granda

Cosmology is investigated within a new, scalar theory of gravitation, which is a preferred-frame bimetric theory with flat background metric. Before coming to cosmology, the motivation for an " ether theory " is exposed at length; the…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Mayeul Arminjon

According to the Dudley-Wichura extension of the Skorohod representation theorem, convergence in distribution to a limit in a separable set is equivalent to the existence of a coupling with elements converging a.s. in the metric. A density…

Probability · Mathematics 2015-09-01 Hermann Thorisson

The distance-redshift relation plays an important role in cosmology. In the standard approach to cosmology it is assumed that this relation is the same as in the homogeneous universe. As the real universe is not homogeneous there are…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Krzysztof Bolejko

The standard method of measuring the galaxy pairwise velocity dispersion on small scales is heavily weighted by the densest regions in a way that is difficult to calibrate. We propose a new statistic which measures the small-scale velocity…

Astrophysics · Physics 2009-10-30 Michael A. Strauss , Jeremiah P. Ostriker , Renyue Cen

Small distortions in the observed shapes of distant galaxies, a cosmic shear due to gravitational lensing, can be used to simultaneously determine the distance-redshift relation, r(z), and the density contrast growth factor, g(z). Both of…

Astrophysics · Physics 2010-04-22 L. Knox , Y. -S. Song , J. A. Tyson

A logic of reciprocity between inertial frames in relative uniform motion is investigated. Relativity allows any reference frame to apply Lorentz Transformation while reciprocity would require the relative frame to use Inverse…

Mathematical Physics · Physics 2007-05-23 Chao Y. Yang

We present a new approach to the statistics of the cosmic density field and to the mass distribution of high-contrast structures, based on the formalism of Cayley trees. Our approach includes in one random process both fluctuations and…

Astrophysics · Physics 2009-10-22 A. Cavaliere , N. Menci

Intriguing parallels between density fluctuation power versus wavenumber on small (mm) and large (Mpc) scales are presented. The comparative study is carried out between fusion plasma measurements and cosmological data. Based on predictions…

Astrophysics · Physics 2016-12-28 N. P. Basse

Some first results are presented regarding the behavior of invariant correlations in simplicial gravity, with an action containing both a bare cosmological term and a lattice higher derivative term. The determination of invariant…

High Energy Physics - Theory · Physics 2009-10-22 Herbert W. Hamber
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