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Related papers: A Co-Scaling Grid for Athena++

200 papers

We introduce an extension to the AthenaK code for general-relativistic magnetohydrodynamics (GRMHD) in dynamical spacetimes using a 3+1 conservative Eulerian formulation. Like the fixed-spacetime GRMHD solver, we use standard finite-volume…

High Energy Astrophysical Phenomena · Physics 2025-01-15 Jacob Fields , Hengrui Zhu , David Radice , James M. Stone , William Cook , Sebastiano Bernuzzi , Boris Daszuta

Many interesting terrestrial and astrophysical scenarios involving magnetic fields can be approached in axial geometry. Even though the Lagrangian smoothed particle hydrodynamics (SPH) technique has been successfully extended to handle…

Instrumentation and Methods for Astrophysics · Physics 2022-07-05 Domingo García-Senz , Robert Wissing , Rubén M. Cabezón

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 propose a new method to conserve the total energy to round-off error in grid-based codes for hydrodynamic simulations with self-gravity. A formula for the energy flux due to the work done by the the self-gravitational force is given, so…

Instrumentation and Methods for Astrophysics · Physics 2012-10-02 Yan-Fei Jiang , Mikhail Belyaev , Jeremy Goodman , James M. Stone

Using $10,\!080^3$ grid simulations, we analyze scale-dependent alignment in driven, compressible, no net-flux magnetohydrodynamic turbulence. The plasma self-organizes into localized, strongly aligned regions. Alignment spans all primitive…

Plasma Physics · Physics 2025-04-23 James R. Beattie , Amitava Bhattacharjee

We introduce an effective action for non-dissipative magnetohydrodynamics. A crucial guiding principle is the generalized global symmetry of electrodynamics, which naturally leads to introducing a "dual photon" as the degree of freedom…

High Energy Physics - Theory · Physics 2018-11-13 Paolo Glorioso , Dam Thanh Son

Hydrodynamical simulations are the most accurate way to model structure formation in the universe, but they often involve a large number of astrophysical parameters modeling subgrid physics, in addition to cosmological parameters. This…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-05 Benjamin Horowitz , Zarija Lukic

We describe the magnetohydrodynamics (MHD) code CRONOS, which has been used in astrophysics and space physics studies in recent years. CRONOS has been designed to be easily adaptable to the problem at hand, where the user can expand or…

Instrumentation and Methods for Astrophysics · Physics 2018-07-04 R. Kissmann , J. Kleimann , B. L. Krebl , T. Wiengarten

We develop a new framework for the modelling of charged fluid dynamics in general relativity. The model, which builds on a recently developed variational multi-fluid model for dissipative fluids, accounts for relevant effects like the…

General Relativity and Quantum Cosmology · Physics 2017-05-31 N. Andersson , K. Dionysopoulou , I. Hawke , G. L. Comer

In gravitationally stratified fluids, length scales are normally much greater in the horizontal direction than in the vertical one. When modelling these fluids it can be advantageous to use the hydrostatic approximation, which filters out…

Instrumentation and Methods for Astrophysics · Physics 2013-07-29 Jonathan Braithwaite , Yuri Cavecchi

We present the formulation, algorithm and numerical tests of the magnetohydrodynamic-particle-in-cell (MHD-PIC) method with particles treated under the guiding center approximation, which we term the MHD-gPIC method, and it is implemented…

High Energy Astrophysical Phenomena · Physics 2025-10-20 Zitao Hu , Xue-Ning Bai , Xiaochen Sun

Motivated by the consistent histories approach to quantum mechanics, we examine a simple model of hydrodynamic coarse-graining for a scalar field. It consists in averaging the field over spatial regions of size L and constructing the…

General Relativity and Quantum Cosmology · Physics 2007-05-23 C. Anastopoulos

This work studies the hydrodynamics of self-gravitating compressible isothermal fluids. We show that the hydrodynamic evolution equations in absence of viscosity are scale covariant. We study the evolution of the time dependent fluctuations…

Astrophysics · Physics 2009-10-31 B. Semelin , N. Sanchez , H. J. de Vega

We outline the content and theoretical support for the proposal of "hydrodynamics on (mini)superspace" (or a non-linear extension of quantum cosmology) as an effective framework for quantum gravity in a cosmological context. The basis for…

General Relativity and Quantum Cosmology · Physics 2024-03-19 Daniele Oriti

We present the derivation of hydrodynamical equations for a perfect fluid in General Relativity, within the 3+1 decomposition of spacetime framework, using only primitive variables. Primitive variables are opposed to conserved variables, as…

General Relativity and Quantum Cosmology · Physics 2023-04-17 Gaël Servignat , Jerome Novak , Isabel Cordero-Carrión

We adapt a modern scheme of smoothed particle hydrodynamics (SPH) to our tree N-body/SPH galactic chemodynamics code GCD+. The applied scheme includes imple- mentations of the artificial viscosity switch and artificial thermal conductivity…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Daisuke Kawata , Takashi Okamoto , Brad K. Gibson , David J. Barnes , Renyue Cen

We set up the construction of generic (d+2)-dimensional metrics corresponding to (d+1)-dimensional fluids, representing holographically the hydrodynamic regimes of the putative dual theories. We give general seed equilibrium metrics…

High Energy Physics - Theory · Physics 2015-02-04 Natalia Pinzani-Fokeeva , Marika Taylor

We present a new open-source axisymmetric general relativistic hydrodynamics code Gmunu (General-relativistic multigrid numerical solver) which uses a multigrid method to solve the elliptic metric equations in the conformally flat condition…

General Relativity and Quantum Cosmology · Physics 2020-09-24 Patrick Chi-Kit Cheong , Lap-Ming Lin , Tjonnie Guang-Feng Li

The evolution of magnetized quark gluon plasma (QGP) in the framework of magneto-hydrodynamics is the focus of our study. We are investigating the temporal and spatial evolution of QGP using a second order viscous hydrodynamic framework.…

Nuclear Theory · Physics 2024-03-05 M. karimabadi , A. F. Kord , B. Azadegan

Holographic renormalization group flows can be interpreted in terms of effective field theory. Based on such an interpretation, a formula for the running scaling dimensions of gauge-invariant operators along such flows is proposed. The…

High Energy Physics - Theory · Physics 2011-02-23 Wolfgang Mueck