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Related papers: Potential-Density Basis Sets for Galactic Disks

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Efficient expansions of the gravitational field of (dark) haloes have two main uses in the modelling of galaxies: first, they provide a compact representation of numerically-constructed (or real) cosmological haloes, incorporating the…

Astrophysics of Galaxies · Physics 2018-02-21 E. J. Lilley , J. L. Sanders , N. W. Evans , D. Erkal

The basis of the identity representation of a polyhedral group is able to describe functions with symmetries of a platonic solid, i.e., 3-D objects which geometrically obey the cubic symmetries. However, to describe the dynamic of assembles…

Group Theory · Mathematics 2016-11-22 Nan Xu

We present a novel positive potential-density pair expansion for modelling galaxies, based on the Miyamoto-Nagai (MN) disc. By using three sets of such discs, each one of them aligned along each symmetry axis, we are able to reconstruct a…

Astrophysics of Galaxies · Physics 2016-04-14 Armando Rojas-Niño , Justin I. Read , Luis Aguilar , Maxime Delorme

An integral equation-based numerical method for scattering from multi-dielectric cylinders is presented. Electromagnetic fields are represented via layer potentials in terms of surface densities with physical interpretations. The existence…

Computational Physics · Physics 2019-05-01 Johan Helsing , Anders Karlsson

An infinite family of exact solutions of the electrovacuum Einstein-Maxwell equations is presented. The family is static, axially symmetric and describe thin disks composed by electrically polarized material in a conformastatic spacetime.…

General Relativity and Quantum Cosmology · Physics 2017-04-24 Anamaria Navarro , F. D. Lora-Clavijo , Guillermo A. González

We demonstrate the high accuracy of the density splitting method to compute the gravitational potential and field in the plane of razor-thin, axially symmetric discs, as preliminarily outlined in Pierens & Hure (2004). Because residual…

Astrophysics · Physics 2009-11-10 Jean-Marc Hure , Arnaud Pierens

This paper constructs an analytic framework for calculating the assembly of galactic disks from the collapse of gas within dark matter halos, with the goal of determining the surface density profiles. Gas parcels (baryons) fall through the…

Astrophysics · Physics 2008-11-26 Fred C. Adams , Anthony M. Bloch

An identity that relates multipolar solutions of the Einstein equations to Newtonian potentials of bars with linear densities proportional to Legendre polynomials is used to construct analytical potential-density pairs of infinitesimally…

Astrophysics of Galaxies · Physics 2010-10-28 D. Vogt , P. S. Letelier

The saturation conditions for bending modes in inhomogeneous thin stellar disks that follow from an analysis of the dispersion relation are compared with those derived from $N$-body simulations. In the central regions of inhomogeneous…

Astrophysics · Physics 2009-11-10 N. Ya. Sotnikova , S. A. Rodionov

A general method is presented for constructing distribution functions for flat systems whose surface density and Toomre's Q number profile is given. The purpose of these functions is to provide plausible galactic models and assess their…

Astrophysics · Physics 2007-05-23 C. Pichon , D. Lynden-Bell

[Abridged] Recently we have found that a family of models of partially relaxed, anisotropic stellar systems, inspired earlier by studies of incomplete violent relaxation, exhibits some interesting thermodynamic properties. Here we present a…

Astrophysics · Physics 2009-11-10 M. Trenti , G. Bertin

In this paper, we propose compactly supported radial basis functions for solving some well- known classes of astrophysics problems categorized as non-linear singular initial ordinary dif- ferential equations on a semi-infinite domain. To…

Numerical Analysis · Mathematics 2016-05-31 Kourosh Parand , Mohammad Hemami

The study of off-equatorial orbits in razor-thin disks is still in its beginnings. Contrary to what was presented in the literature in recent publications, the vertical stability criterion for equatorial circular orbits cannot be based on…

Astrophysics of Galaxies · Physics 2015-04-03 Ronaldo S. S. Vieira , Javier Ramos-Caro

When developing and assessing density functional theory methods, a finite basis set is usually employed. In most cases, however, the issue of basis set dependency is neglected. Here, we assess several basis sets and functionals. In…

Chemical Physics · Physics 2007-05-23 A. Daniel Boese , Jan M. L. Martin , Nicholas C. Handy

This paper constructs polynomial bases that capture the structure of the de Rham complex with boundary conditions in disks and cylinders (both periodic and finite) in a way that respects rotational symmetry. The starting point is explicit…

Numerical Analysis · Mathematics 2026-03-26 Sheehan Olver

Static packings of perfectly rigid particles are investigated theoretically and numerically. The problem of finding the contact forces in such packings is formulated mathematically. Letting the values of the contact forces define a vector…

Materials Science · Physics 2009-11-10 Sean McNamara , Hans Herrmann

First-principles density functional theory (DFT) codes which employ a localized basis offer advantages over those which use plane-wave bases, such as better scaling with system size and better suitability to low-dimensional systems. The…

Materials Science · Physics 2024-11-25 Daniel Bennett , Michele Pizzochero , Javier Junquera , Efthimios Kaxiras

An analytical model is presented for calculating the surface density as a function of radius $\Sigma(r)$ in protoplanetary disks in which a planet has opened a gap. This model is also applicable to circumbinary disks with extreme binary…

Earth and Planetary Astrophysics · Physics 2015-05-15 Paul C. Duffell

A simple yet general method for constructing basis sets for molecular electronic structure calculations is presented. These basis sets consist of atomic natural orbitals from a multi-configurational self-consistent field calculation…

Materials Science · Physics 2015-05-19 F. R. Petruzielo , Julien Toulouse , C. J. Umrigar

We examine a possible formation scenario of galactic thick discs with numerical simulations. Thick discs have previously been argued to form in clumpy disc phase in the high-redshift Universe, which host giant clumps of <10^9 M_sun in their…

Astrophysics of Galaxies · Physics 2015-06-18 Shigeki Inoue , Takayuki R. Saitoh