English
Related papers

Related papers: On the global density slope-anisotropy inequality

200 papers

Following the seminal result of An & Evans, known as the central density slope-anisotropy theorem, successive investigations unexpectedly revealed that the density slope-anisotropy inequality holds not only at the center, but at all radii…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Luca Ciotti , Lucia Morganti

Recently, some intriguing results have lead to speculations whether the central density slope -- velocity dispersion anisotropy inequality (An & Evans) actually holds at all radii for spherical dynamical systems. We extend these studies by…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Emmanuel Van Hese , Maarten Baes , Herwig Dejonghe

General criteria to check the positivity of the distribution function (phase-space consistency) of stellar systems of assigned density and anisotropy profile are useful starting points in Jeans-based modeling. Here we substantially extend…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 Luca Ciotti , Lucia Morganti

It is well known that the density and anisotropy profile in the inner regions of a stellar system with positive phase-space distribution function are not fully independent. Here we study the interplay between density profile and orbital…

Astrophysics · Physics 2009-11-13 Luca Ciotti , Lucia Morganti

One can solve the Jeans equation analytically for equilibrated dark matter structures, once given two pieces of input from numerical simulations. These inputs are 1) a connection between phase-space density and radius, and 2) a connection…

Astrophysics · Physics 2015-06-24 Steen H. Hansen , Ben Moore , Joachim Stadel

We identify a universal relation between the radial density slope \alpha (r) and the velocity anisotropy \beta (r) for equilibrated structures. This relation holds for a variety of systems, including disk galaxy mergers, spherical…

Astrophysics · Physics 2007-05-23 Steen H. Hansen , Ben Moore

A method is presented for finding anisotropic distribution functions for stellar systems with known, spherically symmetric, densities, which depends only on the two classical integrals of the energy and the magnitude of the angular…

Astrophysics · Physics 2008-12-31 Zhenglu Jiang , Leonid Ossipkov

For a wide class of self-gravitating systems, we show that if the density is cusped like 1/r^{gamma} near the center, then the limiting value of the anisotropy parameter beta = 1 - <v_T^2>/(2<v_r^2>) at the center may not be greater than…

Astrophysics · Physics 2007-05-23 J. An , N. W. Evans

We study a new class of equilibrium two-parametric distribution functions of spherical stellar systems with radially anisotropic velocity distribution of stars. The models are less singular counterparts of the so called generalized…

Astrophysics of Galaxies · Physics 2015-06-16 E. V. Polyachenko , V. L. Polyachenko , I. G. Shukhman

This paper presents a set of new conditions on the augmented density of a spherical anisotropic system that is necessary for the underlying two-integral phase-space distribution function to be non-negative. In particular, it is shown that…

Mathematical Physics · Physics 2011-06-07 J. An

We analyze two volume limited galaxy samples from the SDSS photometric and spectroscopic data to test the isotropy in the local Universe. We use information entropy to quantify the global anisotropy in the galaxy distribution at different…

Cosmology and Nongalactic Astrophysics · Physics 2018-12-12 Suman Sarkar , Biswajit Pandey , Rishi Khatri

Modern cosmology rests on the cosmological principle, that on large enough scales the Universe is both homogeneous and isotropic. A corollary is that galaxies' spin vectors should be isotropically distributed on the sky. This has been…

Astrophysics of Galaxies · Physics 2025-03-03 Dhruva Patel , Harry Desmond

Following earlier authors, we re-examine constraints on the radial velocity anisotropy of generic stellar systems using arguments for phase space density positivity, stability, and separability. It is known that although the majority of…

Astrophysics of Galaxies · Physics 2015-06-19 Jeremy A. Barber , Hongsheng Zhao

One can solve the Jeans equation analytically for equilibrated dark matter structures, once given two pieces of input from numerical simulations. These inputs are 1) a connection between phase-space density and radius, and 2) a connection…

Astrophysics · Physics 2009-11-13 Steen H. Hansen , Joachim Stadel

If the augmented density of a spherical anisotropic system is assumed to be multiplicatively separable to functions of the potential and the radius, the radial function, which can be completely specified by the behavior of the anisotropy…

Cosmology and Nongalactic Astrophysics · Physics 2011-07-21 J. An

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

Assuming the separable augmented density, it is always possible to construct a distribution function of a spherical population with any given density and anisotropy. We consider under what conditions the distribution constructed as such is…

Cosmology and Nongalactic Astrophysics · Physics 2012-04-19 J. An , E. Van Hese , M. Baes

We present the first study of the isotropy of the distribution of morphological types of galaxies in the Local Universe out to around 200 Mpc using more than 60,000 galaxies from the HyperLeda database. We divide the sky into two opposite…

Astrophysics of Galaxies · Physics 2017-01-18 Behnam Javanmardi , Pavel Kroupa

We develop the complete theory for the collective plasmon modes of an interacting electron system in the presence of explicit mass (or velocity) anisotropy in the corresponding non-interacting situation, with the effective Fermi velocity…

Mesoscale and Nanoscale Physics · Physics 2021-01-27 Seongjin Ahn , S. Das Sarma

We investigate the universal electronic transport for a mixed $d_{x^2-y^2}$+s-wave superconductor in the presence of an anisotropic elliptical Fermi surface. Similar to the universal low-temperature transport predicted in a…

Superconductivity · Physics 2009-10-31 W. C. Wu , D. Branch , J. P. Carbotte
‹ Prev 1 2 3 10 Next ›