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We perform fully general relativistic simulations of rotating stellar core collapse in three spatial dimension. A parametric equation of state is adopted following Dimmelmeier et al. The early stage of the collapse is followed by an…

Astrophysics · Physics 2008-11-26 Masaru Shibata , Yu-ichirou Sekiguchi

We propose a class of nonlocal diffusion systems on time-varying domains, and fully characterize their asymptotic dynamics in the asymptotically fixed, time-periodic and unbounded cases. The kernel is not necessarily symmetric or compactly…

Analysis of PDEs · Mathematics 2025-02-11 Xiandong Lin , Hailong Ye , Xiao-Qiang Zhao

Measurements of a weighted energy density average taken in the vacuum state of a conformal field theory in $1+1$ dimensions are randomly distributed with vanishing expectation value. The probability distribution is computed in closed form…

High Energy Physics - Theory · Physics 2020-01-29 Matthew C. Anthony , Christopher J. Fewster

A quantum system consisting of two subsystems is separable if its density matrix can be written as $\rho=\sum_A w_A\,\rho_A'\otimes\rho_A''$, where $\rho_A'$ and $\rho_A''$ are density matrices for the two subsytems. In this Letter, it is…

Quantum Physics · Physics 2011-05-05 Asher Peres

A non-linear gravitational model with a multidimensional geometry and quadratic scalar curvature is considered. For certain parameter ranges, the extra dimensions are stabilized if the internal spaces have negative curvature. As a…

General Relativity and Quantum Cosmology · Physics 2007-05-23 U. Guenther , P. Moniz , A. Zhuk

The process referred to as "semi-convection" in astrophysics and "double-diffusive convection in the diffusive regime" in Earth and planetary sciences, occurs in stellar and planetary interiors in regions which are stable according to the…

Solar and Stellar Astrophysics · Physics 2015-06-03 Giovanni M. Mirouh , Pascale Garaud , Stephan Stellmach , Adrienne L. Traxler , Toby S. Wood

Lane Emden differential equation of the polytropic gas sphere could be used to construct simple models of stellar structures, star clusters and many configurations in astrophysics. This differential equation suffers from the singularity at…

Solar and Stellar Astrophysics · Physics 2020-03-25 E. A. -B. Abd-Elsalam , Mohamed I. Nouh

A variety of statistics based on sample spacings has been studied in the literature for testing goodness-of-fit to parametric distributions. To test the goodness-of-fit to a nonparametric class of univariate shape-constrained densities,…

Statistics Theory · Mathematics 2024-10-28 Kwun Chuen Gary Chan , Hok Kan Ling , Chuan-Fa Tang , Sheung Chi Phillip Yam

Using the standard dynamical theory of spherical systems, we calculate the properties of spherical galaxies and clusters whose density profiles obey the universal form first obtained in high resolution cosmological N-body simulations by…

Astrophysics · Physics 2009-10-31 Ewa L. Lokas , Gary A. Mamon

We introduce "anamorphic" cosmology, an approach for explaining the smoothness and flatness of the universe on large scales and the generation of a nearly scale-invariant spectrum of adiabatic density perturbations. The defining feature is…

Cosmology and Nongalactic Astrophysics · Physics 2015-10-02 Anna Ijjas , Paul J. Steinhardt

The purpose of this study is to describe a perfect fluid matter distribution that leads to a constant curvature region, thanks to the effect of a non-minimal coupling. This distribution exhibits a density profile within the range found in…

General Relativity and Quantum Cosmology · Physics 2011-07-04 J. Páramos , O. Bertolami

In the present paper we develop an algorithm for all spherically symmetric anisotropic charged fluid distribution. Considering a new source function $\nu(r)$ we find out a set of solutions which is physically well behaved and represent…

General Relativity and Quantum Cosmology · Physics 2017-06-12 S. K. Maurya , Y. K. Gupta , Saibal Ray

In this work we show how the composition of maps allows us to multiply, enlarge and move stable domains in phase and parameter spaces of discrete nonlinear systems. Using H\'enon maps with distinct parameters we generate many identical…

Chaotic Dynamics · Physics 2017-08-16 Cesar Manchein , Rafael M. da Silva , Marcus W. Beims

In this paper, we evaluate the complexity of the non-static cylindrical geometry with anisotropic matter configuration in the framework of modified Gauss-Bonnet theory. In this perspective, we calculate modified field equations, the C…

General Relativity and Quantum Cosmology · Physics 2025-06-05 M. Zeeshan Gul , W. Ahmad , M. M. M. Nasir , Faisal Javed , Orhan Donmez , Bander Almutairi

We examine the idea that dynamical parameters can be estimated by identifying locations in the solar neighbourhood where simulated velocity distributions match the observed local distribution. Here, the dynamical influence of both the…

Astrophysics · Physics 2009-11-13 Dalia Chakrabarty

We present a generic mechanism by which reproducing microorganisms, with a diffusivity that depends on the local population density, can form stable patterns. It is known that a decrease of swimming speed with density can promote separation…

Populations and Evolution · Quantitative Biology 2010-07-13 M. E. Cates , D. Marenduzzo , I. Pagonabarraga , J. Tailleur

We further study the stochastic model discussed in Ref.[2] in which positive and negative particles diffuse in an asymmetric, CP invariant way on a ring. The positive particles hop clockwise, the negative counter-clockwise and…

Statistical Mechanics · Physics 2007-05-23 Peter F. Arndt , Vladimir Rittenberg

The anthropic principle has been proposed as an explanation for the observed value of the cosmological constant. Here we revisit this proposal by allowing for variation between universes in the amplitude of the scale-invariant primordial…

High Energy Physics - Theory · Physics 2007-05-23 Michael L. Graesser , Stephen D. H. Hsu , Alejandro Jenkins , Mark B. Wise

This paper proposes a phase space to compare the static packings of a granular system compatible to a macrostate that is set by the external stress. The nature of this phase space is analyzed, showing that the consideration of the allowed…

Soft Condensed Matter · Physics 2019-02-20 Ignacio G. Tejada

Generalized statistical models of voids and hierarchical structure in cosmology are developed. The often quoted negative binomial model and frequently used thermodynamic model are shown to be special cases of a more general distribution…

Astrophysics · Physics 2008-11-26 Aram Z. Mekjian