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Related papers: Charting Galactic Accelerations: When and How to E…

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We present a data-driven method for reconstructing the galactic acceleration field from phase-space measurements of stellar streams. Our approach is based on a flexible and differentiable fit to the stream in phase-space, enabling a direct…

Astrophysics of Galaxies · Physics 2023-03-31 Jacob Nibauer , Vasily Belokurov , Miles Cranmer , Jeremy Goodman , Shirley Ho

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

This paper uses dynamical invariants to describe the evolution of collisionless systems subject to time-dependent gravitational forces without resorting to maximum-entropy probabilities. We show that collisionless relaxation can be viewed…

Astrophysics of Galaxies · Physics 2015-06-03 Jorge Peñarrubia

A deterministic method is proposed for solving the Boltzmann equation. The method employs a Galerkin discretization of the velocity space and adopts, as trial and test functions, the collocation basis functions based on weights and roots of…

Computational Physics · Physics 2013-11-19 Gian Pietro Ghiroldi , Livio Gibelli

The sensitivity of direct detection experiments depends on the phase-space distribution of dark matter near the Sun, which can be modeled theoretically using cosmological hydrodynamical simulations of Milky Way-like galaxies. However,…

High Energy Physics - Phenomenology · Physics 2026-04-08 Dylan Folsom , Carlos Blanco , Mariangela Lisanti , Lina Necib , Mark Vogelsberger , Lars Hernquist

In this paper we extend Chandrasekhar and von Neumann's analysis of the statistics of the gravitational field to systems in which particles (e.g. stars, galaxies) are not homogeneously distributed. We derive a distribution function…

Astrophysics · Physics 2007-05-23 A. Del Popolo , M. Gambera , x

Gravitational lensing and stellar dynamics are two independent methods, based solely on gravity, to study the mass distributions of galaxies. Both methods suffer from degeneracies, however, that are difficult to break. In this paper, we…

Astrophysics · Physics 2011-04-05 Matteo Barnabe' , Leon V. E. Koopmans

We construct analytical phase-space solutions for perturbations of flat disks by performing a power series expansion for the radius and the velocity coordinates. We show that this approach translates into an elegant mathematical formulation…

Astrophysics · Physics 2011-05-23 P. Vauterin , H. Dejonghe

We present a method for solving the two-dimensional linearized collisionless Boltzmann equation using Fourier expansion along the orbits. It resembles very much solutions present in the literature, but it differs by the fact that everything…

Astrophysics · Physics 2007-05-23 P. Vauterin , H. Dejonghe

We present robust constraints from the Sloan Digital Sky Survey (SDSS) on the shape and distribution of the dark matter halo within the Milky Way (MW). Using the number density distribution and kinematics of SDSS halo stars, we probe the…

This paper shows how a self-consistent dynamical model can be obtained by fitting the gravitational potential of the Milky Way to the stellar kinematics and densities from Gaia data. Using the Besancon Galaxy Model we derive a potential and…

We propose a new method to determine the shape of the gravitational potential of the dark matter (DM) halo of the Milky Way (MW) with the galactocentric tangential velocities of a sample of hypervelocity stars (HVSs). We compute the…

Astrophysics of Galaxies · Physics 2022-07-20 Arianna Gallo , Luisa Ostorero , Sankha Subhra Chakrabarty , Stefano Ebagezio , Antonaldo Diaferio

We present a new technique to constrain the gravitational potential of a galaxy from the observed stellar mass surface density alone under a number of assumptions. It uses the classical Eddington Inversion Method to compute the phase-space…

Astrophysics of Galaxies · Physics 2025-02-19 Jorge Sanchez Almeida , Ignacio Trujillo , Mireia Montes , Angel R. Plastino

In this paper we extend Chandrasekhar and von Neumann's analysis of the statistics of the gravitational field to systems in which particles (e.g. stars, galaxies) are not homogeneously distributed. We derive a distribution function W(F,d…

Astrophysics · Physics 2007-05-23 A. Del Popolo

Rotational speed is an important physical parameter of stars and knowing the distribution of stellar rotational velocities is essential for the understanding stellar evolution. However, it cannot be measured directly but the convolution of…

Instrumentation and Methods for Astrophysics · Physics 2015-06-18 Michel Cure , Diego F. Rial , Alejandra Christen , Julia Cassetti

We propose a method for constructing the time-dependent phase space distribution function (DF) of a collisionless system from an isolated kinematic snapshot. In general, the problem of mapping a single snapshot to a time-dependent function…

Astrophysics of Galaxies · Physics 2021-07-21 Keir Darling , Lawrence M. Widrow

Based on the Sloan Digital Sky Survey (SDSS), we develop a new monte-carlo based method to estimate the photometric metallicity distribution function (MDF) for stars in the Milky Way. Compared with other photometric calibration methods,…

Astrophysics of Galaxies · Physics 2016-07-27 Jiayin Gu , Cuihua Du , Yingjie jing , Wenbo Zuo

We investigate velocity statistics of homogeneous inelastic gases using the Boltzmann equation. Employing an approximate uniform collision rate, we obtain analytic results valid in arbitrary dimension. In the freely evolving case, the…

Statistical Mechanics · Physics 2007-05-23 E. Ben-Naim , P. L. Krapivsky

As a step towards a more accurate modelling of redshift-space distortions in galaxy surveys, we develop a general description of the probability distribution function of galaxy pairwise velocities within the framework of the so-called…

Cosmology and Nongalactic Astrophysics · Physics 2015-02-04 Davide Bianchi , Matteo Chiesa , Luigi Guzzo

We present a new approach for quantifying the abundance of galaxy clusters and constraining cosmological parameters using dynamical measurements. In the standard method, galaxy line-of-sight (LOS) velocities, $v$, or velocity dispersions…

Cosmology and Nongalactic Astrophysics · Physics 2017-01-25 M. Ntampaka , H. Trac , J. Cisewski , L. C. Price