hi Luciano, we've done something like this in https://arxiv.org/abs/1204.2019 you can indeed find cosmological apparent horizons using AHFinderDirect, the trick is to add the following parameter:
AHFinderDirect::surface_definition[1] = "inner expansion" hope this helps. cheers, Miguel On 23/07/2022 06:48, Luciano Combi wrote: > Hi all, > > I'm trying to use AHFinderDirect to find the apparent horizon in the de > Sitter metric, implemented > in the Exact thorn in comoving coordinates. I tried a few things but cannot > get it to work. Have > someone tried something similar, i.e. using the AHFD in cosmological > spacetimes instead of BHs? > Below I attach a typical parfile I used > > Thanks! > ------------------------------------------------------- > # flesh > cactus::cctk_itlast = 0 > > ActiveThorns = "PUGH" > driver::ghost_size = 3 > driver::global_nx = 120 > driver::global_ny = 120 > driver::global_nz = 120 ##57 > > ActiveThorns = "CoordBase SymBase CartGrid3D" > grid::avoid_origin = "false" > grid::type = "byspacing" > grid::dxyz = 0.2 > > ActiveThorns = "ADMBase ADMCoupling StaticConformal CoordGauge SpaceMask > Exact" > ADMBase::initial_lapse = "exact" > ADMBase::initial_shift = "exact" > ADMBase::initial_data = "exact" > ADMBase::lapse_evolution_method = "exact" > ADMBase::shift_evolution_method = "exact" > ADMBase::metric_type = "physical" > Exact::exact_model = "de Sitter+Lambda" > Exact::de_Sitter_Lambda__scale = 0.50 > > > ######################################## > > ActiveThorns = "IOUtil" > IOUtil::parfile_write = "no" > > ######################################## > > ActiveThorns = "AEILocalInterp PUGHInterp PUGHReduce SphericalSurface > AHFinderDirect" > > AHFinderDirect::print_timing_stats = "true" > > AHFinderDirect::output_Theta_every = 1 > AHFinderDirect::h_base_file_name = "dS.h" > AHFinderDirect::Theta_base_file_name = "dS.Theta" > > AHFinderDirect::N_horizons = 1 > AHFinderDirect::origin_x[1] = 0.0 > AHFinderDirect::origin_y[1] = 0.0 > AHFinderDirect::origin_z[1] = 0.0 > > AHFinderDirect::initial_guess_method[1] = "coordinate sphere" > AHFinderDirect::initial_guess__coord_sphere__x_center[1] = 0.0 > AHFinderDirect::initial_guess__coord_sphere__y_center[1] = 0.0 > AHFinderDirect::initial_guess__coord_sphere__z_center[1] = 0.0 > AHFinderDirect::initial_guess__coord_sphere__radius[1] = 1.0 > ------------------------ > -- > *Luc Combi* > CONICET PhD fellow (Buenos Aires, Argentina) > Instituto Argentino de Radioastronomía > > _______________________________________________ > Users mailing list > [email protected] > http://lists.einsteintoolkit.org/mailman/listinfo/users _______________________________________________ Users mailing list [email protected] http://lists.einsteintoolkit.org/mailman/listinfo/users
