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Related papers: Dynamical models with a general anisotropy profile

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While hidden class models of various types arise in many statistical applications, it is often difficult to establish the identifiability of their parameters. Focusing on models in which there is some structure of independence of some of…

Statistics Theory · Mathematics 2009-09-01 Elizabeth S. Allman , Catherine Matias , John A. Rhodes

General relativistic anisotropic fluid models whose fluid flow lines form a shear-free, irrotational, geodesic timelike congruence are examined. These models are of Petrov type D, and are assumed to have zero heat flux and an anisotropic…

General Relativity and Quantum Cosmology · Physics 2010-04-06 Des J. Mc Manus , Alan A. Coley

Anisotropy of the permeability tensor in statistically uniform porous media of sizes used in typical computer simulations is studied. Although such systems are assumed to be isotropic by default, we show that de facto their anisotropic…

Fluid Dynamics · Physics 2015-05-13 Zbigniew Koza , Maciej Matyka , Arzhang Khalili

Using N-body simulations we study the phenomenon of radial orbit instability occurring in dark matter haloes of the size of a dwarf galaxy. We carried out simulations of seven spherical models, with the same standard NFW density profile but…

Astrophysics of Galaxies · Physics 2016-10-21 Grzegorz Gajda , Ewa L. Lokas , Radoslaw Wojtak

Elliptical galaxies are modelled with a a 4-component model: Sersic stars, LCDM dark matter (DM), hot gas and central black hole. DM is negligible in the inner regions, which are dominated by stars and the central black hole. This prevents…

Astrophysics · Physics 2014-12-15 Gary A. Mamon , Ewa L. Lokas

A new nonlinear hyperelastic bending model for shells formulated directly in surface form is presented, and compared to four prominently used bending models. Through an essential set of elementary nonlinear bending test cases, the stresses…

Computational Engineering, Finance, and Science · Computer Science 2023-04-20 Eshwar J. Savitha , Roger A. Sauer

In this paper, we consider the problem of parameter sensitivity in models of complex dynamical systems through the lens of information geometry. We calculate the sensitivity of model behavior to variations in parameters. In most cases,…

Statistical Mechanics · Physics 2019-07-17 Benjamin L. Francis , Mark K. Transtrum

Traditionally, the mass / velocity anisotropy degeneracy (MAD) inherent in the spherical, stationary, non-streaming Jeans equation has been handled by assuming a mass profile and fitting models to the observed kinematical data. Here, the…

Cosmology and Nongalactic Astrophysics · Physics 2010-02-11 Gary A. Mamon , Gwenael Boué

We highlight some recent new delevelopments concerning the sparse representation of possibly high-dimensional functions exhibiting strong anisotropic features and low regularity in isotropic Sobolev or Besov scales. Specifically, we focus…

Numerical Analysis · Mathematics 2014-09-30 Wolfgang Dahmen , Chunyan Huang , Gitta Kutyniok , Wang-Q Lim , Christoph Schwab , Gerrit Welper

We consider the macroscopic model derived by Degond and Motsch from a time-continuous version of the Vicsek model, describing the interaction orientation in a large number of self-propelled particles. In this article, we study the influence…

Mathematical Physics · Physics 2013-01-18 Amic Frouvelle

We demonstrate a general relativistic approach to model dark matter halos using the Einstein cluster, with the matter stress-energy generated by collisionless particles moving on circular geodesics in all possible angular directions and…

General Relativity and Quantum Cosmology · Physics 2025-05-23 Ritwik Acharyya , Pritam Banerjee , Sayan Kar

Phase transition problems on curved surfaces can lead to a panopticon of fascinating patterns. In this paper we consider finite element approximations of phase field models with a spatially inhomogeneous and anisotropic surface energy…

Numerical Analysis · Mathematics 2025-06-09 Harald Garcke , Robert Nürnberg

Dark matter N-body simulations suggest that the velocity distribution of dark matter is anisotropic. In this work we employ a mass model for the Milky Way whose parameters are determined from a fit to kinematical data. Then we adopt an…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Nassim Bozorgnia , Riccardo Catena , Thomas Schwetz

In the previous paper of this series, we proposed a new function to fit halo density profiles out to large radii. This truncated Einasto profile models the inner, orbiting matter as $\rho_{\rm orb} \propto \exp \left[-2/\alpha\ (r / r_{\rm…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-24 Benedikt Diemer

Halo Models of large scale structure provide powerful and indispensable tools for phenomenological understanding of the clustering of matter in the Universe. While the halo model builds structures out of the superposition of haloes,…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-26 Alice Chen , Niayesh Afshordi

Cosmological simulations suggest that dark matter haloes are not spherical, but typically moderately to strongly triaxial systems. We investigate methods to convert spherical potential-density pairs into axisymmetric ones, in which the…

Astrophysics · Physics 2009-11-13 Maarten Baes

A mean field model is presented for the configuration dependent effective demagnetizing and anisotropy fields in assemblies of exchange decoupled magnetic particles of arbitrary shape which are expressed in terms of the demagnetizing…

Mesoscale and Nanoscale Physics · Physics 2014-08-27 Juan Manuel Martinez-Huerta , Armando Encinas , Joaquin De La Torre Medina , Luc Piraux

We explore a function with two shape parameters for the dark-matter halo density profile subject to baryonic effects, which is a special case of the general Zhao family of models applied to simulated dark matter haloes by Dekel et al. This…

We investigate a compact spherically symmetric relativistic body with anisotropic particle pressure profiles. The distribution possesses characteristics relevant to modeling compact stars within the framework of general relativity. For this…

General Relativity and Quantum Cosmology · Physics 2018-02-28 S. K. Maurya , Ayan Banerjee , Sudan Hansraj

Fiber-reinforced soft biological tissues are typically modeled as hyperelastic, anisotropic, and nearly incompressible materials. To enforce incompressibility a multiplicative split of the deformation gradient into a volumetric and an…

Numerical Analysis · Mathematics 2022-04-13 Elias Karabelas , Matthias A. F. Gsell , Gundolf Haase , Gernot Plank , Christoph M. Augustin
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