Users June 2021

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19 participants
26 discussions

recon_method dependency (weno)
by Hee Il Kim 07 Jul '21

07 Jul '21

Hi I'm reporting on recon_method dependency issue at least found in Turing and Lorentz. I've been studying BNS evolution by taking some of the Parma group models as references (DOI: 10.1103/PhysRevD.93.064047). But there were significant differences in merger time, t_merger. At the moment, I will put aside direct comparison between the GRHydro of Parma and recents ones. What I've found is that WENO of Turing/Lorentz produces much shorter inspiraling time (See the attached figure). But WENO-Z/PPM/MP5, they all produce similar inspiraling time. Of course, depending on resolutions, they produce different merging behaviour but as shown in the figure, higher-res PPM matches with lower-res WENO-Z nicely, which is consistent with our expectations. I've got the identical results for both Turing and Lorentz versions. I've missed recent GRHydro developments for a long time and I have no guesses for the discrepancy. I hope GRHydro developers examine this issue for the consistency of the recon_method. Thanks for your help in advance. Hee Il

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Einstein Toolkit Meeting Reminder
by users＠einsteintoolkit.org 30 Jun '21

30 Jun '21

Hello, Please consider joining the weekly Einstein Toolkit phone call at 9:00 am US central time on Thursdays. For details on how to connect and what agenda items are to be discussed, use the link below. https://docs.einsteintoolkit.org/et-docs/Main_Page#Weekly_Users_Call --The Maintainers

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Agenda for Thursday's Meeting
by users＠einsteintoolkit.org 28 Jun '21

28 Jun '21

Please update the Wiki with agenda items for Thursday's meeting. Thanks! https://docs.einsteintoolkit.org/et-docs/meeting_agenda --The Maintainers

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Meeting minutes for 2021-06-24
by Atul Kedia 24 Jun '21

24 Jun '21

Present: Peter D, Roland H, Joshua Faber, Miguel G, Zach E, Maria H, Yosef Z, Atul K Chair: Peter D, Minutes: Atul K * Anything before the agenda? Roland - Lorene discussion with Josh. Roland - 2 years ago there were discussions about Lorene2 on ET. Did not get updated back then. Josh - Summary: Generating BNS ID, to increase catalog. Using Lorene from the website ( http://lorene.obspm.fr/). There are two versions (French and English) of the classes. Do essentially the same. French is older, and is used for JF’s BNS ID. English is slightly harder to use. French one is mostly usable with the Meudon_Bin_NS. Needs testing and cataloging of how to generate ID, and thorns that read it. Driver routines distinguish the French and English versions. There’s a directory which contains the files (executables?) for the two. Some of the math is different too. Roland - The one on ET only has (or compiles perhaps) classes that are needed for reading ID by ET. * SPEC benchmark contribution [https://bitbucket.org/einsteintoolkit/tickets/issues/2470] [RH, SB] Roland - They had a question about increasing runtime. We have to respond. * ET 2021 NA summer school [http://lists.einsteintoolkit.org/pipermail/users/2021-May/007944.html] [RH] Roland - Close to 200 participants. 18 lightning talks. Finalizing the program. Reaching out to Peter for LSU virtual machines. Peter - will talk with Steve. * Mugshots for ET gallery runners [RH] Roland - Will send email to gallery test runners for their mugshot to give them more visibility. This was discussed in an earlier ET meeting. Will (likely) add the mugshot of all the testers along with the maintainers page but not going to keep emeritus ET testers mugshots. * [https://www.einsteintoolkit.org/tools/unanswered.php unanswered question on mailing list] * [ https: //bitbucket.org/einsteintoolkit/tickets/issues?status=open&status=new&sort=- updated_on open tickets sorted by update time] #2539 Roland - installed on a new VM with no issues. Freshly installed. Want to include instructions on error reporting, and how to label the particular bugs. Can’t be “blocker” unless it causes issues to many machines. #2534 Roland gonna look into it. If only happening with things evolved with MoL, should cause issues with gridarrays. Yosef - does not make sense to evolve gridarrays in AMR. If it is AMR, it needs to be updated when the nearest grid element is updated. Makes doing everything very messy. #2413: Roland - Writing documentation remaining. Poisson, Single Stable neutron star, Binary Black hole : needs to be “resolved”. * [ https: //bitbucket.org/einsteintoolkit/tickets/issues?status=new&status=open&sort=- updated_on&q=Please%20review tickets ready for review] #332 : Roland - Old ticket by Bruno Mundim. Probably an ‘Enhancement’. Future chairs and minute takers: 1 July : Chair Peter, Minutes Roland. 8 July : Chair: -- , Minutes Miguel G. ---------------------------- End of Call ---------------------------- Atul Kedia PhD Candidate University of Notre Dame

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Einstein Toolkit Meeting Reminder
by users＠einsteintoolkit.org 23 Jun '21

23 Jun '21

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Agenda for Thursday's Meeting
by users＠einsteintoolkit.org 21 Jun '21

21 Jun '21

Please update the Wiki with agenda items for Thursday's meeting. Thanks! https://docs.einsteintoolkit.org/et-docs/meeting_agenda --The Maintainers

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Postdoctoral positions in computational relativity/cosmology/fluid dynamics (IBM, Daresbury, UK)
by eloisa.bentivegna 18 Jun '21

18 Jun '21

Dear colleagues, IBM Research is seeking to fill three postdoctoral positions, with start dates in the second half of 2021. Candidates with a background in any aspect of numerical relativity, computational cosmology, and/or fluid dynamics are invited to apply. Evidence of strong competence in large-scale scientific computing is required. Previous experience with optimization, AI/ML techniques, heterogeneous computing, or past involvement with industrial research projects would be an advantage. Applications should be submitted via our online system: https://careers.ibm.com/job/13128396/ and will be reviewed immediately. The deadline for full consideration is June 23, but the positions will remain open until suitable candidates are appointed. Applications from traditionally underrepresented groups are especially welcome. Best regards, Eloisa

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Issue with thorn Trigger
by Lorenzo Ennoggi 18 Jun '21

18 Jun '21

Dear all, I would like to restart a simulation from a checkpoint enlarging the finest refinement level in my grid. In particular, I would like to change CarpetRegrid2::radius_1[5] = 20.1 to CarpetRegrid2::radius_1[5] = 25. I tried to do that by making the parameter CarpetRegrid2::radius_1 always steerable and adding the following lines to my parameter file: ActiveThorns = "Trigger" Trigger::Trigger_Number = 1 Trigger::Trigger_Checked_Variable[0] = "hydrobase::rho" Trigger::Trigger_Relation[0] = ">" Trigger::Trigger_Checked_Value[0] = 1.e-4 Trigger::Trigger_Reduction[0] = "maximum" Trigger::Trigger_Reaction[0] = "steerparam" Trigger::Trigger_Steered_Parameter_Thorn[0] = "CarpetRegrid2" Trigger::Trigger_Steered_Parameter_Name[0] = "radius_1[5]" Trigger::Trigger_Steered_Parameter_Value[0] = "25." #New value of the above parameter Trigger::Trigger_Once[0] = 1 #It means "yes" Trigger::Trigger_Debug = 1 #It means "yes" In this way, the trigger should act immediately, as the maximum of rho is ~1e-3 in my case. Indeed, it looks like the trigger is working fine, as the standard output says [...] INFO (Trigger): Testing triggers INFO (Trigger): last_checked: -1 INFO (Trigger): reducing trigger 0 red_handle 2 varindex 428 INFO (Trigger): reducing was ok INFO (Trigger): trigger nr. 0 fullfilled for rho (0.000804>0.000100) INFO (Trigger): Steering parameter INFO (Trigger): Parameter steered [...] but unfortunately, looking at the 2D output with VisIt, the finest refinement level does not get enlarged (i.e. radius_1[5] does not appear to have been steered at all). Do you have any suggestions on how to get this trigger to work? Or, are you aware of other ways of obtaining the same result without using the thorn Trigger? I attach the parameter file in case you need it. Thank you very much in advance for your help. Sincerely, Lorenzo Ennoggi

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Black hole excision
by Hon Ka HUI 18 Jun '21

18 Jun '21

Hello, I am following the Parma group's par file to simulate binary neutron stars merging into a black hole. In particular I adopt the following lines into my parfile but it looks like everything is "excised" at the very first iteration (the maximum density suddenly becomes ~10e-11, basically the atmosphere density settings). Could someone please guide me how this should be done properly? or what parameter settings do I need to set as well? With Regards, Ken #------------------------------------------------------------------------------ # AHFinder ActiveThorns = "AHFinderDirect" # This is later steered AHFinderDirect::find_every = 0 AHFinderDirect::run_at_CCTK_POST_RECOVER_VARIABLES = no AHFinderDirect::move_origins = yes AHFinderDirect::reshape_while_moving = yes AHFinderDirect::predict_origin_movement = yes AHFinderDirect::geometry_interpolator_name = "Lagrange polynomial interpolation" AHFinderDirect::geometry_interpolator_pars = "order=4" AHFinderDirect::surface_interpolator_name = "Lagrange polynomial interpolation" AHFinderDirect::surface_interpolator_pars = "order=4" AHFinderDirect::output_h_every = 128 AHFinderDirect::N_horizons = 1 AHFinderDirect::which_surface_to_store_info [1] = 0 AHFinderDirect::reset_horizon_after_not_finding [1] = no AHFinderDirect::initial_guess__coord_sphere__radius [1] = 1.3528 # Hydroexcision ActiveThorns = "SetMask_SphericalSurface" SetMask_SphericalSurface::SetMask_SurfaceIndex[0] = 0 SetMask_SphericalSurface::SetMask_RadiusFactor[0] = 0.6 SetMask_SphericalSurface::SetMask_TrueShape[0] = "false"

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Piecewise-polytrope or tabulated EoS for IllinoisGRMHD
by Prasad R 18 Jun '21

18 Jun '21

Hello, I am using IIlinoisGRMHD for BNS merger simulation. Currently the parameter file uses a polytropic equation of state. How can I incorporate a piecewise-polytrope or tabulated equation of state? With Regards, -- *Prasad R,* *Ph.D. Scholar (INSPIRE Fellow),* *Department of Physics,* *Indian Institute of Science Education & Research (IISER), Bhopal * *Bhauri, Bhopal - 462 066, India *

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Users June 2021