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We present results from the first generation of multi-dimensional general relativistic neutrino hydrodynamics simulations of core-collapse supernovae. A comparison with models computed using either the purely Newtonian approximation or the…

Solar and Stellar Astrophysics · Physics 2011-12-09 Bernhard Mueller , Andreas Marek , Hans-Thomas Janka , Harald Dimmelmeier

We perform a series of simplified numerical experiments to explore how rotation impacts on the three-dimensional (3D) hydrodynamics of core-collapse supernovae. For the sake of our systematic study, we employ a light-bulb scheme to trigger…

High Energy Astrophysical Phenomena · Physics 2015-06-19 Ko Nakamura , Takami Kuroda , Tomoya Takiwaki , Kei Kotake

Dispersion of low-density rigid particles with complex geometries is ubiquitous in both natural and industrial environments. We show that while explicit methods for coupling the incompressible Navier-Stokes equations and Newton's equations…

Computational Physics · Physics 2015-11-06 Uǧis Lācis , Kunihiko Taira , Shervin Bagheri

Multidimensional shock-capturing numerical schemes for special relativistic hydrodynamics (RHD) are computationally more expensive than their correspondent Euler versions, due to the nonlinear relations between conservative and primitive…

Astrophysics · Physics 2009-11-07 L. Del Zanna , N. Bucciantini

I summarize, in the form of an extended abstract, the ongoing efforts at the University of Arizona (and in collaboration) to understand core-collapse supernovae theoretically. Included are short discussions of 1D (SESAME) and 2D (VULCAN/2D)…

Astrophysics · Physics 2007-05-23 Adam Burrows

We present a set of new numerical methods that are relevant to calculating radiation pressure terms in hydrodynamics calculations, with a particular focus on massive star formation. The radiation force is determined from a Monte Carlo…

Solar and Stellar Astrophysics · Physics 2015-06-23 Tim J. Harries

A two dimensional hydrochemical hybrid code, KM2, is constructed to deal with astrophysical problems that would require coupled hydrodynamical and chemical evolution. The code assumes axisymmetry in cylindrical coordinate system, and…

Instrumentation and Methods for Astrophysics · Physics 2015-08-06 Kazutaka Motoyama , Oscar Morata , Hsien Shang , Ruben Krasnopolsky , Tatsuhiko Hasegawa

We derive the Hydrodynamics for a system of N active, spherical, underdamped particles, interacting through conservative forces. At the microscopic level, we represent the evolution of the particles in terms of the Kramers equation for the…

Statistical Mechanics · Physics 2022-03-15 Umberto Marini Bettolo Marconi , Andrea Puglisi , Lorenzo Caprini

The accurate modeling of mode hybridization and calculation of radiative relaxation rates have been crucial to the design and optimization of superconducting quantum devices. In this work, we introduce a spectral theory for the…

Quantum Physics · Physics 2024-04-11 Dung N. Pham , Richard D. Li , Hakan E. Türeci

The Cahn-Hilliard-Navier-Stokes (CHNS) equations represent the fundamental building blocks of hydrodynamic phase-field models for multiphase fluid flow dynamics. Due to the coupling between the Navier-Stokes equation and the Cahn-Hilliard…

Numerical Analysis · Mathematics 2021-07-28 Jia Zhao

A great deal of theoretical and experimental efforts have been devoted in the last decades to the study of long-wavelength photodetection mechanisms in field-effect transistors hosting two-dimensional (2D) electron systems. A particularly…

Mesoscale and Nanoscale Physics · Physics 2019-02-13 Alessandro Principi , Denis Bandurin , Habib Rostami , Marco Polini

We describe a computational framework for simulating suspensions of rigid particles in Newtonian Stokes flow. One central building block is a collision-resolution algorithm that overcomes the numerical constraints arising from particle…

Computational Engineering, Finance, and Science · Computer Science 2020-06-24 Wen Yan , Eduardo Corona , Dhairya Malhotra , Shravan Veerapaneni , Michael Shelley

We present in this paper a multigroup model for radiation hydrodynamics to account for variations of the gas opacity as a function of frequency. The entropy closure model (M1) is applied to multigroup radiation transfer in a radiation…

High Energy Astrophysical Phenomena · Physics 2015-05-27 N. M. H. Vaytet , E. Audit , B. Dubroca , F. Delahaye

We present detailed simulations of the interaction of a stream emanating from a mass-losing secondary with the core of a massive supergiant in the slow merger of the two stars inside a common envelope. The dynamics of the stream can be…

Astrophysics · Physics 2009-11-07 N. Ivanova , Ph. Podsiadlowski , H. Spruit

Both relativistic and non-relativistic two-fluid models of neutron star cores are constructed, using the constrained variational formalism developed by Brandon Carter and co-workers. We consider a mixture of superfluid neutrons and…

Astrophysics · Physics 2008-08-05 N. Chamel

The numerical solution of relativistic hydrodynamics equations in conservative form requires root-finding algorithms that invert the conservative-to-primitive variables map. These algorithms employ the equation of state of the fluid and can…

Instrumentation and Methods for Astrophysics · Physics 2021-11-15 Tobias Dieselhorst , William Cook , Sebastiano Bernuzzi , David Radice

We present new two-dimensional (2D) axisymmetric neutrino radiation/hydrodynamic models of core-collapse supernova (CCSN) cores. We use the CASTRO code, which incorporates truly multi-dimensional, multi-group, flux-limited diffusion (MGFLD)…

Solar and Stellar Astrophysics · Physics 2015-06-19 Joshua C. Dolence , Adam Burrows , Weiqun Zhang

Modeling the dynamics of most astrophysical structures requires an adequate description of the radiation-matter interaction. Several numerical (magneto)hydrodynamics codes were upgraded with a radiation module to fulfill this request.…

Instrumentation and Methods for Astrophysics · Physics 2019-11-06 Salvatore Colombo , Laurent Ibgui , Salvatore Orlando , Raphael Rodriguez , Guadalupe Espinosa , Matthias González , Chantal Stehlé , Giovanni Peres

We present a hierarchical approach for enhancing the robustness of numerical solvers for modelling radiative MHD flows in multi-dimensions. This approach is based on clustering the entries of the global Jacobian in a hierarchical manner…

Mathematical Physics · Physics 2009-11-10 A. A. Hujeirat

We develop a formalism to model slowly rotating superfluid Newtonian neutron stars. A two-fluid model is used to describe the matter, where one fluid is the superfluid neutrons that are believed to exist in the inner crust and core of…

Astrophysics · Physics 2009-11-06 R. Prix , G. L. Comer , N. Andersson