Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Lagrangian hydrodynamics code MAGMA2   We present the methodology and performance of the new Lagrangian
hydrodynamics code MAGMA2, a Smoothed Particle Hydrodynamics code that benefits
from a number of non-standard enhancements. By default it uses high-order
smoothing kernels and wherever gradients are needed, they are calculated via
accurate matrix inversion techniques, but a more conventional formulation with
kernel gradients has also been implemented for comparison purposes. We also
explore a matrix inversion formulation of SPH with a symmetrisation in the
particle indices that is not frequently used. We find interesting advantages of
this formulation in some of the tests, for example, a substantial reduction of
surface tension effects for non-ideal particle setups and more accurate peak
densities in Sedov blast waves. MAGMA2 uses artificial viscosity, but enhanced
by techniques that are commonly used in finite volume schemes such as
reconstruction and slope limiting. While simple to implement, this approach
efficiently suppresses particle noise, but at the same time drastically reduces
dissipation in locations where it is not needed and actually unwanted. We
demonstrate the performance of the new code in a number of challenging
benchmark tests including e.g. multi-dimensional vorticity creating
Schulz-Rinne-type Riemann problems and more astrophysical tests such as a
collision between two stars to demonstrate its robustness and excellent
conservation properties.

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The categories of this paper are: dg-ga
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The categories of this paper are: bayes-an
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The categories of this paper are: patt-sol
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The categories of this paper are: math-ph
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The categories of this paper are: cmp-lg
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The categories of this paper are: stat
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The categories of this paper are: math
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The categories of this paper are: chem-ph
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The categories of this paper are: acc-phys
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The categories of this paper are: supr-con
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The categories of this paper are: nucl-ex
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The categories of this paper are: hep-th
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The categories of this paper are: alg-geom
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The categories of this paper are: cond-mat
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The categories of this paper are: chao-dyn
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The categories of this paper are: solv-int