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Related papers: Tomography of Collisionless Stellar Systems

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We propose a new numerical technique for following the evolution of a self-gravitating collisionless system in general relativity. Matter is modeled as a scalar field obeying the coupled Klein-Gordon and Einstein equations. A phase space…

Astrophysics · Physics 2009-10-28 Lawrence M. Widrow

Placed slightly out of dynamical equilibrium, an isolated stellar system quickly returns towards a steady virialized state. We study this process of collisionless relaxation using the matrix method of linear response theory. We show that…

Astrophysics of Galaxies · Physics 2024-09-04 Simon Rozier , Raphaël Errani

Recently, the theory of symmetric teleparallel equivalent of general relativity (STEGR) has gained much interest in the cosmology and astrophysics community. Within this theory, we discuss the method of deriving a stellar isotropic model.…

General Relativity and Quantum Cosmology · Physics 2025-04-08 G. G. L. Nashed , Amare Abebe

Following the techniques of [4], we formulate a Normal Form Lemma suited to close to be integrable Hamiltonian systems where not all the coordinates are action angles. The Lemma turns to be useful in the theory of KAM tori of…

Dynamical Systems · Mathematics 2017-10-10 Gabriella Pinzari

In this paper, we present our conclusions from the numerical study of the collapse of a destabilized collisionless stellar system. We use both direct integration of the Vlasov-Poisson equations and an N-body tree code to obtain our results,…

Astrophysics · Physics 2009-11-07 Thomas E. C. Merrall , Richard N. Henriksen

A particle method for reproducing the phase space of collisionless stellar systems is described. The key idea originates in Liouville's theorem which states that the distribution function (DF) at time t can be derived from tracing necessary…

Astrophysics · Physics 2009-10-30 Shunsuke Hozumi

We review and complete the kinetic theory of spatially inhomogeneous stellar systems when collective effects (dressing of the stars by their polarization cloud) are neglected. We start from the BBGKY hierarchy issued from the Liouville…

Astrophysics of Galaxies · Physics 2015-06-11 Pierre-Henri Chavanis

Starting with the relativistic Boltzmann equation for a system of particles defined by a distribution function, we have derived the virial relation for a spherical structure within an expanding background in the context of general…

General Relativity and Quantum Cosmology · Physics 2016-02-03 Reza Javadinezhad , Javad T. Firouzjaee , Reza Mansouri

In the paper, gridless particle techniques are presented in order to solve problems involving electrostatic, collisionless plasmas. The method makes use of computational particles having the shape of spherical shells or of rings, and can be…

Plasma Physics · Physics 2019-01-24 E. Boella , G. Coppa , A. D Angola , B. Peiretti Paradisi

We formulate and study a generalized virial theorem for contact Hamiltonian systems. Such systems describe mechanical systems in the presence of simple dissipative forces such as Rayleigh friction, or the vertical motion of a particle…

Mathematical Physics · Physics 2026-01-06 Aritra Ghosh

The present work represents a step to deal with stellar structure using a pure geometric approach. A geometric field theory is used to construct a model for a spherically symmetric configuration. The model obtained can be considered as a…

General Relativity and Quantum Cosmology · Physics 2011-09-27 M. I. Wanas , Samah A. Ammar

Within a cosmological context, we study the behaviour of collisionless particles in the weak field approximation to General Relativity, allowing for large gradients of the fields and relativistic velocities for the particles. We consider a…

Cosmology and Nongalactic Astrophysics · Physics 2016-02-03 Julian Adamek , Mateja Gosenca , Shaun Hotchkiss

We elaborate on the notion of generalized tomograms, both in the classical and quantum domains. We construct a scheme of star-products of thick tomographic symbols and obtain in explicit form the kernels of classical and quantum generalized…

Quantum Physics · Physics 2015-05-07 M. Asorey , P. Facchi , V. I. Man'ko , G. Marmo , S. Pascazio , E. C. G. Sudarshan

Complex vectorial light fields, non-separable in their polarization and spatial degree of freedom, are of relevance in a wide variety of fields encompassing microscopy, metrology, communication and topological studies. Controversially, they…

The objective of the work summarised here has been to exploit and extend ideas from plasma physics and accelerator dynamics to formulate a unified description of collisionless relaxation that views violent relaxation, Landau damping, and…

Astrophysics · Physics 2007-05-23 Henry E. Kandrup

The use of the tensor virial theorem (TVT) as a diagnostic of anisotropic velocity distributions in galaxies is revisited. The TVT provides a rigorous global link between velocity anisotropy, rotation and shape, but the quantities appearing…

Astrophysics · Physics 2009-11-11 James Binney

We present a new cosmological test using the distribution of galaxies around cosmic voids without assuming a fiducial cosmology. The test is based on a physical model for the void-galaxy cross-correlation function projected along and…

Cosmology and Nongalactic Astrophysics · Physics 2019-04-10 Carlos M. Correa , Dante J. Paz , Nelson D. Padilla , Andrés N. Ruiz , Raúl E. Angulo , Ariel G. Sánchez

This paper is devoted to consideration of the theory of collisionless statistical systems with interparticle scalar interaction. The mathematical model of such systems is constructed and the exact solution of Vlasov equation for isotropic…

General Relativity and Quantum Cosmology · Physics 2016-04-27 Yu. G. Ignat'ev

Quantum tomography is a method to experimentally extract all that is observable about a quantum mechanical system. We introduce quantum tomography to collider physics with the illustration of the angular distribution of lepton pairs. The…

High Energy Physics - Phenomenology · Physics 2018-01-17 John C. Martens , John P. Ralston , J. D. Tapia Takaki

I review the method of Doppler tomography which translates binary-star line profiles taken at a series of orbital phases into a distribution of emission over the binary. I begin with a discussion of the basic principles behind Doppler…

Astrophysics · Physics 2007-05-23 T. R. Marsh
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