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▲Galiliean-invariant cosmological hydrodynamical simulations on a moving meshwwwmpa.mpa-garching.mpg.de
19 points by gone35 2 days ago | 8 comments
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antognini 3 hours ago [-]
Worth noting that this paper is from 2009.

For anyone interested they released the code about a decade later: https://arepo-code.org/getting-started

hbrav 1 minutes ago [-]
> about a decade later

Practically the blink of an eye to a cosmologist!

jauntywundrkind 4 hours ago [-]
> is based on a mov- ing unstructured mesh defined by the Voronoi tessellation of a set of discrete points. The mesh is used to solve the hyperbolic conservation laws of ideal hydrodynamics with a finite volume approach, based on a second-order unsplit Godunov scheme with an exact Riemann solver. The mesh-generating points can in principle be moved ar- bitrarily.

The visual examples at the bottom feel very impressive. I haven't diced fully in, but it feels like there's points where they need to be, that represent the simulation well.

Where-as the previous grids couldn't adapt to the problem.

Neat to see!

curt15 1 hours ago [-]
Is classical HPC still alive and well in the current neural network craze?
semi-extrinsic 21 minutes ago [-]
Definitely. There are techniques that purport to replace traditional PDE solvers (FNOs, LNOs, all sorts of PINNs, ...), but I have yet to see something that can give reasonable predictions of even a second-year grad student level fluid dynamics problem without extensive fine-tuning on an extremely similar problem.
ted_dunning 3 hours ago [-]
This is really nice work that solves a lot of practical problems related to fixed gridding.

I wonder if this could be applied to electromagnetic simulations. Common systems in that field have even more serious problems with gridding.

moktonar 3 hours ago [-]
Do this in time and not only in space, using energy-momentum as the metric and you get Gravity and General Relativity. They are so close and yet they don’t seem to see it.
HelloUsername 5 hours ago [-]
(HN never fails to give me titles that I can use for my own random music projects :P)