An extension of Gmunu: General-relativistic resistive magnetohydrodynamics based on staggered-meshed constrained transport with elliptic cleaning. (arXiv:2110.03732v1 [astro-ph.IM])
<a href="http://arxiv.org/find/astro-ph/1/au:+Cheong_P/0/1/0/all/0/1">Patrick Chi-Kit Cheong</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Yip_A/0/1/0/all/0/1">Anson Ka Long Yip</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Li_T/0/1/0/all/0/1">Tjonnie Guang Feng Li</a>

We present the implementation of general-relativistic resistive
magnetohydrodynamics solvers and three divergence-free handling approaches
adopted in the General-relativistic multigrid numerical (Gmunu) code.

In particular, implicit-explicit Runge-Kutta schemes are used to deal with
the stiff terms in the evolution equations for small resistivity.

Three divergence-free handling methods are (i) hyperbolic divergence cleaning
through a generalised Lagrange multiplier (GLM); (ii) staggered-meshed
constrained transport (CT) schemes and (iii) elliptic cleaning though multigrid
(MG) solver which is applicable in both cell-centred and face-centred (stagger
grid) magnetic field.

The implementation has been test with a number of numerical benchmarks from
special-relativistic to general-relativistic cases.

We demonstrate that our code can robustly recover a very wide range of
resistivity.

We also illustrate the applications in modelling magnetised neutron stars,
and compare how different divergence-free handling affects the evolution of the
stars.

Furthermore, we show that the preservation of the divergence-free condition
of magnetic field when staggered-meshed constrained transport schemes can be
significantly improved by applying elliptic cleaning.

We present the implementation of general-relativistic resistive
magnetohydrodynamics solvers and three divergence-free handling approaches
adopted in the General-relativistic multigrid numerical (Gmunu) code.

In particular, implicit-explicit Runge-Kutta schemes are used to deal with
the stiff terms in the evolution equations for small resistivity.

Three divergence-free handling methods are (i) hyperbolic divergence cleaning
through a generalised Lagrange multiplier (GLM); (ii) staggered-meshed
constrained transport (CT) schemes and (iii) elliptic cleaning though multigrid
(MG) solver which is applicable in both cell-centred and face-centred (stagger
grid) magnetic field.

The implementation has been test with a number of numerical benchmarks from
special-relativistic to general-relativistic cases.

We demonstrate that our code can robustly recover a very wide range of
resistivity.

We also illustrate the applications in modelling magnetised neutron stars,
and compare how different divergence-free handling affects the evolution of the
stars.

Furthermore, we show that the preservation of the divergence-free condition
of magnetic field when staggered-meshed constrained transport schemes can be
significantly improved by applying elliptic cleaning.

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