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We discuss the nature of the velocity dispersion vs. size relation for molecular clouds. In particular, we add to previous observational results showing that the velocity dispersions in molecular clouds and cores are not purely functions of…

High resolution numerical simulations of stationary inverse energy cascade in two-dimensional turbulence are presented. Deviations from Gaussianity of velocity differences statistics are quantitatively investigated. The level of statistical…

chao-dyn · Physics 2009-10-31 G. Boffetta , A. Celani , M. Vergassola

The basic cosmological distances are linked by the Etherington cosmic distance duality relation, $\eta (z) = D_{L}(z)(1+z)^{-2}/D_{A}(z) \equiv 1$, where $D_{L}$ and $D_{A}$ are, respectively, the luminosity and angular diameter distances.…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 J. A. S. Lima , J. V. Cunha , V. T. Zanchin

In this paper, direct and inverse problems for a space fractional advection dispersion equation on a finite domain are studied. The inverse problem consists in determining the source term from a final observation. We first drive the…

Analysis of PDEs · Mathematics 2014-01-15 Abeer Aldoghaither , Taous-Meriem Laleg-Kirati , Da-Yan Liu

This document expands upon the relationship between discrete and continuous entropy given in (Phys. Rev. Lett. 110 130407), \Violating Continuous Variable Einstein-Podolsky-Rosen Steering with Discrete Measurements". We provide a detailed…

Quantum Physics · Physics 2013-12-11 James Schneeloch

The 1+3 covariant approach and the covariant gauge-invariant approach to perturbations are used to analyze in depth conformal transformations in cosmology. Such techniques allow us to obtain very interesting insights on the physical content…

General Relativity and Quantum Cosmology · Physics 2014-11-20 Sante Carloni , Emilio Elizalde , Sergei Odintsov

We study constraints imposed by the Galilean invariance on linear electromagnetic and elastic responses of two-dimensional gapped systems in background magnetic field. Exact relations between response functions following from the Ward…

Strongly Correlated Electrons · Physics 2015-02-16 Andrey Gromov , Alexander G. Abanov

We analyze the convergence of probability density functions utilizing approximate models for both forward and inverse problems. We consider the standard forward uncertainty quantification problem where an assumed probability density on…

Numerical Analysis · Mathematics 2021-05-04 T. Butler , J. D. Jakeman , T. Wildey

We calculate the relativistic constraint equation which relates the curvature perturbation to the matter density contrast at second order in cosmological perturbation theory. This relativistic "second order Poisson equation" is presented in…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-13 Juan Carlos Hidalgo , Adam J. Christopherson , Karim A. Malik

We point out that, due to the nonlinearity of the Einstein equations, a homogeneous approximation in cosmology leads to the appearance of an additional term in the Friedmann equation. This new term is associated with the spatial…

Astrophysics · Physics 2015-06-24 Gyula Bene , Viktor Czinner , Matyas Vasuth

The fluctuations in the Cosmic Microwave Background (CMB) intensity due to the Sunyaev-Zeldovich (SZ) effect are the sum of a thermal and a kinetic contribution. Separating the two components to measure the peculiar velocity of galaxy…

To explain the cosmic speed up, brought to light by the recent SNIa and CMB observations, we propose the following: a) In a spacetime endowed with a FRW metric, we choose an empirical scale factor that best explains the observations. b) We…

Astrophysics · Physics 2009-11-13 Sohrab Rahvar , Yousef Sobouti

A theory of special inconstancy, in which some fundamental physical constants such as the fine-structure and gravitational constants may vary, is proposed in pregeometry. In the special theory of inconstancy, the \alpha-G relation of…

General Physics · Physics 2015-04-21 Hidezumi Terazawa

The Cosmicflows-2 catalogue is a compendium of peculiar velocity measurements. While it has many objects in common with the COMPOSITE catalogue, a previously analysed collection of peculiar velocity data found to give an unexpectedly large…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-22 Richard Watkins , Hume A. Feldman

Using the formulation of relativistic reconnection by Lyutikov & Uzdensky (2002) we estimate the upper possible rates of reconnection in pulsar winds using Bohm prescription for resistivity. We find that the velocity of plasma inflow into…

Astrophysics · Physics 2007-05-23 Maxim Lyutikov

In the presence of the gravitational field, the energy density of matter no longer coincides with its mass density. A discrepancy exists, of course, also between the associated power spectra. Within the $\Lambda$CDM model, we derive a…

General Relativity and Quantum Cosmology · Physics 2024-04-08 Maxim Eingorn , Ezgi Yilmaz , A. Emrah Yükselci , Alexander Zhuk

We have considered linear two point correlations of the form $1/{x^{\gamma}}$ which are known to have a self-similar behaviour in a $\Omega=1$ universe. We investigate under what conditions the non-linear corrections, calculated using the…

Astrophysics · Physics 2009-10-28 Somnath Bharadwaj

We study the frame dependence/independence of cosmological observables under disformal transformations, extending the previous results regarding conformal transformations, and provide the correspondence between Jordan-frame and…

General Relativity and Quantum Cosmology · Physics 2020-06-17 Takeshi Chiba , Fabio Chibana , Masahide Yamaguchi

We investigate the skewness of galaxy number density fluctuations as a possible probe to test gravity theories. We find that the specific linear combination of the skewness parameters corresponds to the coefficients of the second-order…

Cosmology and Nongalactic Astrophysics · Physics 2023-02-24 Daisuke Yamauchi , Shoya Ishimaru , Takahiko Matsubara , Tomo Takahashi

The present review aims to show that a modified space-time with an invariant minimum speed provides a relation with Weyl geometry in the Newtonian approximation of weak-field. The deformed Special Relativity so-called Symmetrical Special…

General Relativity and Quantum Cosmology · Physics 2023-11-07 Cláudio Nassif Cruz , A. C. Amaro de Faria