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We describe an axisymmetric general relativistic code for rotational core collapse. The code evolves the coupled system of metric and fluid equations using the ADM 3+1 formalism and a conformally flat metric approximation of the Einstein…

Astrophysics · Physics 2009-11-07 Harald Dimmelmeier , Jose A. Font , Ewald Mueller

We develop a general method for the self consistent calculation of the hydrodynamics of an astrophysical object irradiated by a radiation field with an arbitrary strength and spectral energy distribution (SED). Using the XSTAR…

High Energy Astrophysical Phenomena · Physics 2017-03-22 Sergei Dyda , Randall Dannen , Tim Waters , Daniel Proga

I consider the nonaxisymmetric linear theory of a rotating, isothermal magnetohydrodynamic (MHD) shear flow. The analysis is performed in the shearing box, a local model of a thin disk, using a decomposition in terms of shearing waves,…

Astrophysics · Physics 2011-02-11 Bryan M. Johnson

The smoothed particle hydrodynamics (SPH) technique is a purely Lagrangian method, used in numerical simulations of fluids in astrophysics and computational fluid dynamics, among many other fields. SPH simulations with detailed physics…

A particle-in-a-box model of continuous space quantum annealing is proposed and studied numerically by solving the Schr\"odinger wave equation directly. Three types of energy landscapes with multiple local minima are considered, namely a…

Quantum Physics · Physics 2026-05-11 Yang Wei Koh , Youjin Deng

Hydrodynamical interactions between binaries and circumbinary disks (CBDs) play an important role in a variety of astrophysical systems, from young stellar binaries to supermassive black hole binaries. Previous simulations of CBDs have…

High Energy Astrophysical Phenomena · Physics 2023-02-15 Hai-Yang Wang , Xue-Ning Bai , Dong Lai

An implicit Lagrangian hydrodynamics code for general relativistic spherical collapse is presented. This scheme is based on an approximate linearized Riemann solver (Roe type scheme). This code is aimed especially at the calculation of the…

Astrophysics · Physics 2009-10-28 Shoichi Yamada

Global disk simulations provide a powerful tool for investigating accretion and the underlying magnetohydrodynamic turbulence driven by the magneto-rotational instability (MRI). Using them to predict accurately quantities such as stress,…

Instrumentation and Methods for Astrophysics · Physics 2015-06-16 John F. Hawley , Sherwood A. Richers , Xiaoyue Guan , Julian H. Krolik

Chemistry plays a key role in many aspects of astrophysical fluids. Atoms and molecules are agents for heating and cooling, determine the ionization fraction, serve as observational tracers, and build the molecular foundation of life. We…

The nonlinear evolution of the Kelvin-Helmholtz instability is a popular test for code verification. To date, most Kelvin-Helmholtz problems discussed in the literature are ill-posed: they do not converge to any single solution with…

Instrumentation and Methods for Astrophysics · Physics 2021-12-28 Daniel Lecoanet , Michael McCourt , Eliot Quataert , Keaton J. Burns , Geoffrey M. Vasil , Jeffrey S. Oishi , Benjamin P. Brown , James M. Stone , Ryan M. O'Leary

We consider the problem of a generic stabilizer Hamiltonian under local, incoherent Pauli errors. Using two different approaches -- (i) Haah's polynomial formalism arXiv:1204.1063 and (ii) the homological perspective on CSS codes -- we…

Quantum Physics · Physics 2024-03-07 Anasuya Lyons

In this paper we study the gravitational collapse of a molecular hydrogen gas cloud composed of a core plus a gas envelope surrounding the core. We numerically simulate the collapse of four cloud models to take a glimpse to the time…

Solar and Stellar Astrophysics · Physics 2013-08-21 Guillermo Arreaga-Garcia , Julio Saucedo Morales

We have constructed a spherically symmetric structure model in a cosmological background filled with perfect fluid with non-vanishing pressure and studied its quasi-local characteristics. This is done by using the Lema\^{i}tre solution of…

General Relativity and Quantum Cosmology · Physics 2017-12-11 Rahim Moradi , Javad T. Firouzjaee , Reza Mansouri

We present a new general relativistic hydrodynamics code specifically designed to study magneto-rotational, relativistic, stellar core collapse. The code is an extension of an existing (and thoroughly tested) hydrodynamics code, which has…

Astrophysics · Physics 2008-11-26 P. Cerdá-Durán , J. A. Font

The local thermodynamic stability from the charge susceptibility of a holographic superfluid model at finite superfluid velocity is studied in the probe limit. Previous studies show that beyond a finite value of the superfluid velocity, the…

High Energy Physics - Theory · Physics 2024-09-24 Yu-Xiang Cao , Hui Zeng , Zhang-Yu Nie

The aim of this paper is to analyze a model for chemotaxis based on a local sensing mechanism instead of the gradient sensing mechanism used in the celebrated minimal Keller-Segel model. The model we study has the same entropy as the…

Analysis of PDEs · Mathematics 2020-06-05 Martin Burger , Philippe Laurençot , Ariane Trescases

We generalize the classical shadow tomography scheme to a broad class of finite-depth or finite-time local unitary ensembles, known as locally scrambled quantum dynamics, where the unitary ensemble is invariant under local basis…

Quantum Physics · Physics 2025-10-27 Hong-Ye Hu , Soonwon Choi , Yi-Zhuang You

We formulate a data-driven, physics-constrained closure method for coarse-scale numerical simulations of turbulent fluid flows. Our approach involves a closure scheme that is non-local both in space and time, i.e. the closure terms are…

Fluid Dynamics · Physics 2021-02-16 Alexis-Tzianni G. Charalampopoulos , Themistoklis P. Sapsis

Grid-based magnetohydrodynamic (MHD) simulations have proven invaluable for the study of astrophysical accretion disks. However, the fact that angular momentum transport in disks is mediated by MHD turbulence (with structure down to very…

High Energy Astrophysical Phenomena · Physics 2015-05-28 Kareem A. Sorathia , Christopher S. Reynolds , James M. Stone , Kris Beckwith

The initial state of the spherical gravitational collapse in general relativity has been studied with different methods, especially by using {\it a priori} given equations of state that describe the matter as a perfect fluid. We propose an…

General Relativity and Quantum Cosmology · Physics 2024-10-24 Elly Bayona , Hernando Quevedo , Miguel Alcubierre