[Users] Meeting Minutes 2021-03-04

[Steven Brandt]

On 3/4/2021 10:37 AM, Gabella, William E wrote:
> Present: Peter D, Bill G, Roland H, Atul K, Miguel G, Steve B, Karim S
>
> Chair: Peter,   Minutes: Bill
>
> * SPEC benchmark contribution
> [https://bitbucket.org/einsteintoolkit/tickets/issues/2470 task] [RH, SB]
>
> Roland, Sent the Makefile to the person at NVidia and a second version that
> is not sent yet, it is a little nicer.  PUGH run with 8th order finite
> difference and
> seems to run really slow.  Not sure about how long the run the SPEC want.
> Decided as a test case not to use Minkowski ST too man zeros, so put in
> a shifted
> gauge wave.  Started with Maclachlan with gamma driver and 1+log lapse
> (black
> hole driver) and periodic BCs and seems unstable, the amplitude of the
> wave grows.
> Benchmark parameter file chooses the number of cells and the time steps,
> did
> satisfy the Courant condition, it is smaller than 0.4 (that is the
> gallery example),
> even smaller shows the same growth.

This may not be an original thought, but it occurs to me that figuring 
out a better gauge condition might be a good application for machine 
learning, since it's not terribly important that we understand how the 
gauge works, just that it behaves the way we want.

--Steve