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This is a status report on our endeavor to reveal the mechanism of core-collapse supernovae (CCSNe) by large-scale numerical simulations. Multi-dimensionality of the supernova engine, general relativistic magnetohydrodynamics, energy and…

High Energy Astrophysical Phenomena · Physics 2013-04-29 Kei Kotake , Kohsuke Sumiyoshi , Shoichi Yamada , Tomoya Takiwaki , Takami Kuroda , Yudai Suwa , Hiroki Nagakura

We present the new code NADA-FLD to solve multi-dimensional neutrino-hydrodynamics in full general relativity (GR) in spherical polar coordinates. The energy-dependent neutrino transport assumes the flux-limited diffusion (FLD)…

High Energy Astrophysical Phenomena · Physics 2019-10-23 Ninoy Rahman , Oliver Just , H. -Thomas Janka

We present spherically symmetric (1D) and axisymmetric (2D) supernova simulations for a convection-dominated 9 Msun and a 20 Msun progenitor that develops violent activity by the standing-accretion-shock instability (SASI). We compare in…

High Energy Astrophysical Phenomena · Physics 2018-09-20 Oliver Just , Robert Bollig , Hans-Thomas Janka , Martin Obergaulinger , Robert Glas , Shigehiro Nagataki

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

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

Modeling correctly the transport of neutrinos is crucial in some astrophysical scenarios such as core-collapse supernovae and binary neutron star mergers. In this paper, we focus on the truncated-moment formalism, considering only the first…

General Relativity and Quantum Cosmology · Physics 2023-05-30 Manuel R. Izquierdo , Lorenzo Pareschi , Borja Miñano , Joan Massó , Carlos Palenzuela

In a recent paper we presented a new ultra efficient numerical method for solving kinetic equations of the Boltzmann type (G. Dimarco, R. Loubere, Towards an ultra efficient kinetic scheme. Part I: basics on the 689 BGK equation, J. Comp.…

Numerical Analysis · Mathematics 2015-06-12 Giacomo Dimarco , Raphaël Loubere

A recently obtained set of the equations for leading-order (3+1)D anisotropic hydrodynamics is tested against exact solutions of the Boltzmann equation with the collisional kernel treated in the relaxation time approximation. In order to…

High Energy Physics - Phenomenology · Physics 2016-01-20 Leonardo Tinti , Radoslaw Ryblewski , Wojciech Florkowski , Michael Strickland

We present an open-source update to the spherically-symmetric, general-relativistic hydrodynamics, core-collapse supernova (CCSN) code GR1D (O'Connor & Ott, 2010, CQG, 27, 114103). The source code is available at http://www.GR1Dcode.org. We…

High Energy Astrophysical Phenomena · Physics 2015-10-05 Evan O'Connor

Neutrino-matter interactions play an important role in the post-merger evolution of neutron star-neutron star and black hole-neutron star mergers. Most notably, they determine the properties of the bright optical/infrared transients…

High Energy Astrophysical Phenomena · Physics 2018-09-19 Francois Foucart , Matthew D. Duez , Lawerence E. Kidder , Ronny Nguyen , Harald P. Pfeiffer , Mark A. Scheel

We explore the application of Monte Carlo transport methods to solving coupled radiation-hydrodynamics problems. We use a time-dependent, frequency-dependent, 3-dimensional radiation transport code, that is special relativistic and includes…

Instrumentation and Methods for Astrophysics · Physics 2015-06-19 Nathaniel Roth , Daniel Kasen

In one dimension, we present results from comparisons of stationary state multigroup flux-limited diffusion and Boltzmann neutrino transport, focusing on quantities central to the postbounce shock reheating. In two dimensions, we present…

Astrophysics · Physics 2007-05-23 Anthony Mezzacappa

A collision-based hybrid method for the discrete ordinates approximation of the multigroup neutron transport equation is developed for two-dimensional time-dependent problems. At each time step, this algorithm splits the neutron transport…

Computational Physics · Physics 2025-02-17 Ben Whewell , Ryan G. McClarren

We describe an analysis of neutron transport in the interior of model pebble bed reactor (PBR) cores, considering both crystal and random pebble arrangements. Monte Carlo codes were developed for (i) generating random realizations of the…

Nuclear Theory · Physics 2016-02-03 Richard Vasques , Edward W. Larsen

We briefly summarize recent efforts in Garching for modeling stellar core collapse and post-bounce evolution in one and two dimensions. The transport of neutrinos of all flavors is treated by iteratively solving the coupled system of…

Astrophysics · Physics 2007-05-23 H. -Th. Janka , R. Buras , F. S. Kitaura Joyanes , A. Marek , M. Rampp

The overwhelming evidence that the core collapse supernova mechanism is inherently multidimensional, the complexity of the physical processes involved, and the increasing evidence from simulations that the explosion is marginal presents…

In this work I develop a new framework for anisotropic hydrodynamics that generalizes the leading order of the hydrodynamic expansion to the full (3+1)-dimensional anisotropic massive case. Following previous works, my considerations are…

Nuclear Theory · Physics 2015-07-29 Leonardo Tinti

Modeling core-collapse supernovae (CCSNe) with neutrino transport in three dimensions (3D) requires tremendous computing resources and some level of approximation. We present a first comparison study of CCSNe in 3D with different physics…

The multigroup neutron transport equations has been widely used to study the interactions of neutrons with their background materials in nuclear reactors. High-resolution simulations of the multigroup neutron transport equations using…

Numerical Analysis · Mathematics 2019-06-20 Fande Kong , Yaqi Wang , Derek R. Gaston , Alexander D. Lindsay , Cody J. Permann , Richard C. Martineau

We propose a dual-resolution prescription meant for the Boltzmann neutrino transport, in which the advection and collision terms are calculated with different angular resolutions in momentum space. The purpose is to address the issue of the…

High Energy Astrophysical Phenomena · Physics 2025-10-30 Akira Ito , Ryuichiro Akaho , Hiroki Nagakura , Shoichi Yamada