I have been trying a variety of initial guesses, but to no avail.
The setup is, in short:
par_b = 3.0
target_m_plus = 0.25
target_m_minus = 0.75
And the smaller black hole's apparent horizon gets detected easily, which cannot be said of the bigger one. My estimates for the AHFinderDirect were at -1.05 to -0.95 for the center of the ellipsoid/sphere, with initial guesses for the x_radius ranging from 0.25 to 0.4, with y_radius, z _radius about 10-20% smaller.
Am I still not getting enough resolution? The refinement levels in my finest setup around x=-1 are:
Carpet::max_refinement_levels =8
CarpetRegrid2::movement_threshold_1 = 0.16
CarpetRegrid2::num_levels_2 = 8
CarpetRegrid2::position_x_2 = -1.0
CarpetRegrid2::radius_2[ 1] = 64.0
CarpetRegrid2::radius_2[ 2] = 16.0
CarpetRegrid2::radius_2[ 3] = 8.0
CarpetRegrid2::radius_2[ 4] = 4.0
CarpetRegrid2::radius_2[ 5] = 3.0
CarpetRegrid2::radius_2[ 6] = 2.5
CarpetRegrid2::radius_2[ 7] = 2.0
CarpetRegrid2::movement_threshold_2 = 0.16
I do not know a-priori if this apparent horizon is best approximated by an ellipsoid (can one see this before performing the numerical simulation?) or not, but I don't know if I'm on the right track.
It seems weird to me that I cannot find the x=-1 AH, even though the corresponding black hole it is ~3 times more massive.
In another attempt, I tried to copy the philosophy of the setup in the GW150914.rpar file,
setting the center_offset for the two punctures and other parameters, but that didn't work either.
I took
target_mp=0.75, target_mm=0.25,
separation D=6, so xp=D*mm = 1.5, xm=D*mp=-4.5,
par_b=D/2 = 3.0, center_offset=xp-half_D=-1.5
I'm starting to doubt if any of these setups is correct.
By the way, can I somehow redirect the outputs of all MPI processes to one file at real time, better still, override the creation of CCTK_Proc files altogether?
Best regards
Konrad Topolski