#2648: Empty ApplyBCs call in LeanBSSNMoL

Reporter: Samuel Cupp Status: new Milestone: Version: Type: bug Priority: major Component: EinsteinToolkit thorn

Comment (by helvi witek):

After ADM2BSSN one usually has to SYNC, extrapolate and apply symmetry boundary conditions (possibly in a very specific order) and the Gamma auxiliary variables of the BSSN system which involve derivatives so cannot be set in ghost zones and the boundary. Most others can be computed point by point, so that a missing SYNC (missing for sure it seems) will only show up a slight change in regions filled via prolongation (but not in inter-processor ghosts or in restriction target region).

@Roland: Ok, Let me add the relevant part of schedule.ccl:

``` schedule LeanBSSN_adm2bssn at CCTK_INITIAL after ADMBase_PostInitial { LANG: Fortran OPTIONS: Local SYNC: gammat } "Convert initial data into BSSN variables"

schedule GROUP ApplyBCs as LeanBSSN_ApplyBCs at CCTK_INITIAL after LeanBSSN_adm2bssn { } "Apply boundary conditions" ```

‌

In Lean, we extrapolate gammat at the end of the routine “LeanBSSN_adm2bssn”, and sync as shown.

Our understanding was that “ApplyBCs” then applies the symmetry boundary conditions.

-- Ticket URL: https://bitbucket.org/einsteintoolkit/tickets/issues/2648/empty-applybcs-cal...