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Related papers: Actions for axisymmetric potentials

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Knowing the conserved quantities that a galaxy's stellar orbits conform to is important in helping us understand the stellar distribution and structures within the galaxy. Isolating integrals of motion and resonances are particularly…

Astrophysics of Galaxies · Physics 2023-05-10 Richard J. Long , Shude Mao , Yougang Wang

The two-point correlation function of the galaxy distribution is a key cosmological observable that allows us to constrain the dynamical and geometrical state of our Universe. To measure the correlation function we need to know both the…

A bar-like central feature is commonly observed in both nearby and distant spiral-type galaxies, including the Milky Way. While many methods exist to categorise this morphology, no one method has emerged as the field-wide standard. To…

Astrophysics of Galaxies · Physics 2026-04-22 Elizabeth J. Iles , Finn A. Pal , Joss Bland-Hawthorn , Ken Freeman

The parameters of an axisymmetric model for the gravitational potential of the Galaxy have been refined. The basic curve of the Galaxy's rotation in a distance interval of $R:0-190$ kpc was constructed using the velocities of masers,…

Astrophysics of Galaxies · Physics 2026-01-14 V. V. Bobylev , A. T. Bajkova , A. A. Smirnov

We present a new algorithm for estimating the star discrepancy of arbitrary point sets. Similar to the algorithm for discrepancy approximation of Winker and Fang [SIAM J. Numer. Anal. 34 (1997), 2028--2042] it is based on the optimization…

Data Structures and Algorithms · Computer Science 2021-09-21 Michael Gnewuch , Magnus Wahlström , Carola Winzen

This is an addendum to the paper by Cappellari (2008, MNRAS, 390, 71), which presented a simple and efficient method to model the stellar kinematics of axisymmetric stellar systems. The technique reproduces well the integral-field…

Cosmology and Nongalactic Astrophysics · Physics 2012-11-30 Michele Cappellari

For nonsupersymmetric theories, the one-loop effective action can be computed via zeta function regularization in terms of the functional trace of the heat kernel associated with the operator which appears in the quadratic part of the…

High Energy Physics - Theory · Physics 2009-10-30 I. N. McArthur , T. D. Gargett

Quantum corrections of certain types and relevant in certain regimes can be summarised in terms of an effective action calculable, in principle, from the underlying theory. The demands of symmetries, local form of terms and dimensional…

General Relativity and Quantum Cosmology · Physics 2009-04-17 Ghanashyam Date , Sandipan Sengupta

We provide a computational method for quickly determining the correct distribution of optically active nanoparticles for a desired response. This is achieved by simulating the optical response of single nanoparticles and performing a…

Optics · Physics 2019-01-03 Phillip Manley , Min Song , Sven Burger , Martina Schmid

We probe the feasibility of describing the structure of a multi-component axisymmetric galaxy with a dynamical model based on the Jeans equations while taking into account a third integral of motion. We demonstrate that using the third…

Astrophysics of Galaxies · Physics 2016-07-27 Rain Kipper , Peeter Tenjes , Olga Tihhonova , Antti Tamm , Elmo Tempel

A new computational framework for evaluation of the gamma function $\Gamma(z)$ over the complex plane is developed. The algorithm is based on interpolation by rational functions, and generalizes the classical methods of Lanczos…

Numerical Analysis · Mathematics 2021-09-28 Matthew F Causley

Sampling from multimodal distributions is a challenging task in scientific computing. When a distribution has an exact symmetry between the modes, direct jumps among them can accelerate the samplings significantly. However, the…

Numerical Analysis · Mathematics 2024-01-05 Lexing Ying

Numerical interpolation techniques are widely employed for calculating large rational functions in scattering amplitude computations. It has been observed in recent years that these rational functions greatly simplify upon partial…

High Energy Physics - Phenomenology · Physics 2024-12-31 Herschel A. Chawdhry

Examples are presented for appearance of geometric symmetry in the shape of various astronomical objects and phenomena. Usage of these symmetries in astrophysical and extragalactic research is also discussed.

Popular Physics · Physics 2022-01-14 László Szabados

We re-examine the method of deprojection of proper motions, which has been used for finding the velocity ellipsoid of stars in the nearby Galaxy. This method is only legitimate if the lines of sight to the individual stars are uncorrelated…

Astrophysics of Galaxies · Physics 2015-05-14 Paul J. McMillan , James J. Binney

The halo occupation distribution (HOD) approach has proven to be an effective method for modeling galaxy clustering and bias. In this approach, galaxies of a given type are probabilistically assigned to individual halos in N-body…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-15 Juliana Kwan , Katrin Heitmann , Salman Habib , Nikhil Padmanabhan , Hal Finkel , Nick Frontiere , Adrian Pope

Some formulae are presented for finding two-integral distribution functions (DFs) which depends only on the two classical integrals of the energy and the magnitude of the angular momentum with respect to the axis of symmetry for stellar…

Mathematical Physics · Physics 2007-08-28 Zhenglu Jiang , Leonid Ossipkov

We study the possible rotation of cluster galaxies, developing, testing and applying a novel algorithm which identifies rotation, if such does exist, as well as its rotational centre, its axis orientation, rotational velocity amplitude and,…

Cosmology and Nongalactic Astrophysics · Physics 2016-12-16 M. Manolopoulou , M. Plionis

Starting with just the assumption of uniformly distributed orbital orientations, we derive expressions for the distributions of the Keplerian orbital elements as functions of arbitrary distributions of eccentricity and semi-major axis. We…

Instrumentation and Methods for Astrophysics · Physics 2011-01-24 Dmitry Savransky , Eric Cady , N. Jeremy Kasdin

We conduct a thorough study into the feasibility of measuring large-scale correlated proper motions of galaxies with astrometric surveys. We introduce a harmonic formalism for analysing proper motions and their correlation functions on the…

Cosmology and Nongalactic Astrophysics · Physics 2019-06-14 Alex Hall