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It has previously been shown that varying the numerical timestep during a symplectic orbital integration leads to a random walk in energy and angular momentum, destroying the phase space-conserving property of symplectic integrators. Here…

Instrumentation and Methods for Astrophysics · Physics 2015-05-20 Nathan A. Kaib , Thomas Quinn , Ramon Brasser

In this article, theory-based analytical methodologies of astrophysics employed in the modern era are suitably operated alongside a test research-grade telescope to image and determine the orbit of a near-earth asteroid from original…

Earth and Planetary Astrophysics · Physics 2021-09-16 Muhammad Farae , Cameron Woo , Anka Hu

The interaction between the supermassive black hole at the center of the Milky Way, Sagittarius A*, and its accretion disk occasionally produces high-energy flares seen in X-ray, infrared, and radio. One proposed mechanism that produces…

High Energy Astrophysical Phenomena · Physics 2024-04-18 Aviad Levis , Andrew A. Chael , Katherine L. Bouman , Maciek Wielgus , Pratul P. Srinivasan

This paper introduces a multi-frequency factorization method for imaging a time-dependent source, specifically to recover its spatial support and the associated excitation instants. Using far-field data from two opposite directions, we…

Numerical Analysis · Mathematics 2026-04-28 Guanqiu Ma , Hongxia Guo , Guanghui Hu

We are developing a 3D radiation hydrodynamics code to simulate the interaction of convection and pulsation in classical variable stars. One key goal is the ability to carry these simulations to full amplitude in order to compare them with…

Solar and Stellar Astrophysics · Physics 2015-05-27 Chris M. Geroux , Robert G. Deupree

Self-consistent N-body simulations are efficient tools to study galactic dynamics. However, using them to study individual trajectories (or ensembles) in detail can be challenging. Such orbital studies are important to shed light on global…

Astrophysics of Galaxies · Physics 2015-06-17 T. Manos , Rubens E. G. Machado

Gravitating systems surrounded by a dynamic sea of substructures experience fluctuations of the local tidal field which inject kinetic energy into the internal motions. This paper uses stochastic calculus techniques to describe `tidal…

Astrophysics of Galaxies · Physics 2019-02-13 Jorge Peñarrubia

This paper investigates quantized thin vortex rings with an internal structure. The quantization scheme of this dynamical system is based on an earlier the approach proposed by the author. Both energy spectrum and circulation spectrum are…

Fluid Dynamics · Physics 2024-02-21 Sergei V. Talalov

A 3D dynamical model is used to study the motion in the central parts of an elliptical galaxy, hosting a massive and dense nucleus. Our aim is to investigate the regular or chaotic character of the motion, with emphasis in the different…

Astrophysics of Galaxies · Physics 2018-03-14 Euaggelos E. Zotos

We study the recovery of an unknown three-dimensional band-limited signal from multiple noisy observations that are randomly rotated by latent elements of SO(3), where the rotations are drawn from an unknown, non-uniform distribution.…

Signal Processing · Electrical Eng. & Systems 2026-02-25 Tamir Bendory , Dan Edidin , Josh Katz , Shay Kreymer , Nir Sharon

We present a simple and powerful method for extracting transit signals associated with a known transiting planet from noisy light curves. Assuming the orbital period of the planet is known and the signal is periodic, we illustrate that…

Earth and Planetary Astrophysics · Physics 2015-07-09 Johan Samsing

In this paper we discuss a method for the generation of mock tidal streams. Using an ensemble of simulations in an isochrone potential where the actions and frequencies are known, we derive an empirical recipe for the evolving satellite…

Astrophysics of Galaxies · Physics 2015-07-15 Mark A. Fardal , Shuiyao Huang , Martin D. Weinberg

Functions of bound Kerr geodesic motion play a central role in many calculations in relativistic astrophysics, ranging from gravitational-wave generation to self-force and radiation-reaction modeling. Although these functions can be…

General Relativity and Quantum Cosmology · Physics 2025-10-22 Lennox S. Keeble , Alejandro Cárdenas-Avendaño

A new method for determining the nature of the orbital motion (chaotic or regular) of globular clusters in the central region of the Galaxy with a radius of 3.5 kpc, which are most affected by the bar, is proposed. The method is based on…

Astrophysics of Galaxies · Physics 2025-04-30 Anisa Bajkova , Anton Smirnov , Vadim Bobylev

Stars aligned in thin stream-like features (feathers), with widths of $\delta\sim1-10^{\circ}$ and lengths as large as $\Delta l\sim180^{\circ}$, have been observed towards the Anticenter of our Galaxy and their properties mapped in…

Astrophysics of Galaxies · Physics 2018-09-05 Chervin F. P. Laporte , Kathryn V. Johnston , Anastasios Tzanidakis

This paper demonstrates the efficient extraction of unstable recurrent flows from two-dimensional turbulence by using nonlinear triads to diagnose recurrence in direct numerical simulations. Nearly recurrent episodes are identified from…

Fluid Dynamics · Physics 2024-08-12 Edward M. Redfern , Andrei L. Lazer , Dan Lucas

We show that the time frequency analysis of the autocorrelation function is, in many ways, a more appropriate tool to resolve fractional revivals of a wave packet than the usual time domain analysis. This advantage is crucial in…

Quantum Physics · Physics 2009-04-03 Suranjana Ghosh , J. Banerji

The velocity, position, and action variable evolution of a tidal stream drawn out of a star cluster in a triaxial isochrone potential containing a sub-halo population reproduces many of the orbital effects of more general cosmological halos…

Astrophysics of Galaxies · Physics 2015-08-06 Raymond G. Carlberg

We present a novel numerical algorithm developed to reconstuct pulsatile blood flow from ECG-gated CT angiography data. A block-based optimization method was constructed to solve the inverse problem corresponding to the Riccati-type…

Numerical Analysis · Mathematics 2015-11-26 Attila Lovas , Róbert Nagy , Elek Csobo , Brigitta Szilágyi , Péter Sótonyi

We present a method for transforming galaxy rotation curves into radially resolved dynamical chronometers, enabling reconstruction of galaxy assembly histories directly from kinematic data. Within the Nexus Paradigm, the baryonic…

Astrophysics of Galaxies · Physics 2026-04-21 Stuart Marongwe , Stuart A. Kauffman