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Since the advent of the accelerated expanding homogeneous universe model, some other explanations for the supernova Ia dimming have been explored, among which there are inhomogeneous models constructed with exact $\Lambda = 0$ solutions of…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-21 Priti Mishra , Marie-Noëlle Célérier

Let $L$ be a line bundle on a proper, geometrically reduced scheme $X$ over a non-trivially valued non-Archimedean field $K$. Roughly speaking, the non-Archimedean volume of a continuous metric on the Berkovich analytification of $L$…

Algebraic Geometry · Mathematics 2024-11-13 Sébastien Boucksom , Walter Gubler , Florent Martin

We investigate the distribution of the volume and coordination number associated to each particle in a jammed packing of monodisperse hard sphere using the mesoscopic ensemble developed in Nature 453, 606 (2008). Theory predicts an…

Soft Condensed Matter · Physics 2015-05-13 Ping Wang , Chaoming Song , Yuliang Jin , Kun Wang , Hernan A. Makse

We solve for all Szekeres metrics that have a single Killing vector. For quasi hyperboloidal ($\epsilon = -1$) metrics, we find that translational symmetries are possible, but only in metrics that have shell crossings somewhere, while…

General Relativity and Quantum Cosmology · Physics 2017-06-14 Ira Georg , Charles Hellaby

We study the behaviour of the density contrast in quasi-spherical Szekeres spacetime and derive its analytical behaviour as a function of $t$ and $r$. We set up the inhomogeneity using initial data in the form of one extreme value of the…

General Relativity and Quantum Cosmology · Physics 2014-12-24 David Vrba , Otakar Svitek

This study belongs to a series devoted to using Szekeres inhomogeneous models to develop a theoretical framework where observations can be investigated with a wider range of possible interpretations. We look here into the growth of…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 Mustapha Ishak , Austin Peel

Recent work on the Szekeres inhomogeneous cosmological models uncovered a surprising rotation effect. Hellaby showed that the angular $(\theta, \phi)$ coordinates do not have a constant orientation, while Buckley and Schlegel provided…

General Relativity and Quantum Cosmology · Physics 2021-02-10 Charles Hellaby , Robert G. Buckley

Within the framework of hierarchical clustering we show that a simple Press-Schechter-like approximation, based on spherical dynamics, provides a good estimate of the evolution of the density field in the quasi-linear regime up to $\Sigma…

Astrophysics · Physics 2007-05-23 P. Valageas

The Szekeres metric is an inhomogeneous cosmological model without any symmetries. The standard Riemann-type coordinates can be transformed into spherical-type coordinates, but the metric is no longer diagonal, and the constant "radius"…

General Relativity and Quantum Cosmology · Physics 2017-06-27 Charles Hellaby

We present a two-dimensional mesoscopic model of a yield stress material that includes the possibility of local volume fluctuations coupled to shear, in such a way that the shear strength of the material decreases as the local density…

Materials Science · Physics 2022-08-31 E. A. Jagla

This paper develops a unified framework for estimating the volume of a set in $\mathbb{R}^d$ based on observations of points uniformly distributed over the set. The framework applies to all classes of sets satisfying one simple axiom: a…

Statistics Theory · Mathematics 2017-12-22 Nicolai Baldin

Settling velocity statistics for dilute, non-Brownian suspensions of polydisperse spheres having a log-normal size distribution are analysed by Stokesian Dynamics, as a function of the total volume fraction and width of the size…

Fluid Dynamics · Physics 2024-04-30 Heng Li , Lorenzo Botto

Various substances in the liquid state tend to form droplets. In this paper the shape of such droplets is investigated within the spherical model of a lattice gas. We show that in this case the droplet boundary is always diffusive, as…

Statistical Mechanics · Physics 2015-05-20 Anatoly E. Patrick

We examine the growth of eccentricities of a population of particles with initially circular orbits around a central massive body. Successive encounters between pairs of particles increase the eccentricities in the disk on average. As long…

Astrophysics · Physics 2008-11-26 Benjamin F. Collins , Hilke E. Schlichting , Re'em Sari

We examine the spatial extrema (local maxima, minima and saddle points) of the covariant scalars (density, Hubble expansion, spatial curvature and eigenvalues of the shear and electric Weyl tensors) of the quasi-spherical Szekeres dust…

General Relativity and Quantum Cosmology · Physics 2015-11-10 Roberto A. Sussman , Ismael Delgado Gaspar

The signed volume function for polyhedra can be generalized to a mean volume function for volume elements by averaging over the triangulations of the underlying polyhedron. If we consider these up to translation and scaling, the resulting…

Geometric Topology · Mathematics 2014-01-31 Dimitris Vartziotis , Benjamin Himpel

We study quasi-spherical Szekeres space-time (which possess no killing vectors) for perfect fluid, matter with tangential stress only and matter with anisotropic pressure respectively. In the first two cases cosmological solutions have been…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Subenoy Chakraborty , Sanjukta Chakraborty , Ujjal Debnath

We obtain an estimate of the Cheeger isoperimetric constant in terms of the volume growth for a properly immersed submanifold in a Riemannian manifold which possesses at least one pole and sectional curvature bounded from above .

Differential Geometry · Mathematics 2012-04-13 Vicent Gimeno , Vicente Palmer

This paper discusses the phenomenon of backreaction within the Szekeres model. Cosmological backreaction describes how the mean global evolution of the Universe deviates from the Friedmannian evolution. The analysis is based on models of a…

General Relativity and Quantum Cosmology · Physics 2017-06-15 Krzysztof Bolejko

After introducing the Szekeres and Lema\^{\i}tre--Tolman cosmological models, the real-time cosmology program is briefly mentioned. Then, a few widespread misconceptions about the cosmological models are pointed out and corrected.…

General Relativity and Quantum Cosmology · Physics 2015-06-12 Andrzej Krasiński , Krzysztof Bolejko