THIS IS WORK IN PROGRESS
- Philipp Mösta
- Bruno C. Mundim
- Joshua A. Faber
- Roland Haas
- Scott C. Noble
- Tanja Bode
- Frank Löffler
- Christian D. Ott
- Christian Reisswig
- Erik Schnetter
We present the new general-relativistic magnetohydrodynamics (GRMHD)
capabilities of the Einstein Toolkit, an open-source community-driven
numerical relativity and computational relativistic astrophysics
code. The GRMHD extension of the Toolkit builds upon previous releases
and implements the evolution of relativistic magnetised fluids in the
ideal MHD limit in fully dynamical spacetimes using the same
shock-capturing techniques previously applied to hydrodynamical
evolution. In order to maintain the divergence-free character of the
magnetic field, the code implements both hyperbolic divergence
cleaning and constrained transport schemes. We present test results
for a number of MHD tests in Minkowski and curved spacetimes.
Minkowski tests include aligned and oblique planar shocks, cylindrical
explosions, magnetic rotors, Alfv\'en waves and advected loops, as
well as a set of tests designed to study the response of the
divergence cleaning scheme to numerically generated monopoles. We
study the code's performance in curved spacetimes with spherical
accretion onto a black hole on a fixed background spacetime and in
fully dynamical spacetimes by evolutions of a magnetised polytropic
neutron star and of the collapse of a magnetised stellar core. Our
results agree well with exact solutions where these are
available and we demonstrate convergence. All code and input files
used to generate the results are available on
http://einsteintoolkit.org.
This makes our work fully
reproducible and provides new users with an introduction to
applications of the code.
Materials
Monopole Tests
Planar MHD Shocktubes
Cylindrical Shocks
Magnetic Rotor
Alfvén Wave
Loop advection
Bondi Inflow
Magnetized TOV
Rotating Collapse