Users September 2025

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18 participants
21 discussions

Applications Open for Postdoctoral Research Positions
by Kendrick Smith 17 Sep '25

17 Sep '25

Perimeter Institute for Theoretical Physics is inviting applications for Postdoctoral Research positions. Dear Valued Colleague, Perimeter Institute for Theoretical Physics is inviting applications for the Postdoctoral Research Program (https://landing.perimeterinstitute.ca/e3t/Ctc/2I+113/cjL-604/VVCJsX700VFxF2… ) . For more information, please visit the job posting (https://landing.perimeterinstitute.ca/e3t/Ctc/2I+113/cjL-604/VVCJsX700VFxF2… ) . We hope you will share the news by: 1. Forwarding this information directly to prospective candidates who may be interested in this opportunity 2. Downloading, printing, and hanging the poster (https://landing.perimeterinstitute.ca/e3t/Ctc/2I+113/cjL-604/VVCJsX700VFxF2… ) 3. Sharing LinkedIn (https://landing.perimeterinstitute.ca/e3t/Ctc/2I+113/cjL-604/VVCJsX700VFxF2… ) and Facebook (https://landing.perimeterinstitute.ca/e3t/Ctc/2I+113/cjL-604/VVCJsX700VFxF2… ) posts with your social networks Perimeter Institute offers a dynamic, multi-disciplinary environment with maximum research freedom and opportunity to collaborate. We welcome all candidates to apply by November 1, 2025 but applications will be considered until all positions are filled. Thank you in advance for forwarding and sharing this information. Sincerely, Kendrick Smith Committee Chair Perimeter Institute for Theoretical Physics, 31 Caroline Street North, Waterloo, Ontario N2L 2Y5, Canada, 519-569-7600

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Issues Running BNS and GW150914 Example Simulations + storing BSSN variables
by Sandeep Suresh CrangaNORE 15 Sep '25

15 Sep '25

Dear EinsteinToolkit team I am currently running the Binary Neutron Star (BNS) -- (https://einsteintoolkit.org/gallery/bns/index.html) and GW150914 (https://einsteintoolkit.org/gallery/bbh/index.html) binary black hole example simulations on our workstation environment: * *Processors:* AMD EPYC 7542, 32 cores per socket, 2 threads per core (64 logical cores) * *Memory:* 2 TiB RAM * *Kernel:* Linux 5.14.0-570.37.1.el9_6.x86_64 * *OPENMPI version:* mpirun (Open MPI) 4.1.1 Both simulations use the standard example parameter files and initial data provided in the toolkit. I shall describe the problems while running these simulations as two different sections: *BNS: *On running the command ./simfactory/bin/sim create-submit bns --parfile bns.par --procs=<num_procs> --num-threads=<num_threads> --walltime=xx:xx:xx I encounter the error: WARNING level 1 from host panther process 0 in thorn ML_BSSN_Helper, file /system/user/crangano/einstein_toolkit/BNS/configs/sim/build/ML_BSSN_Helper/Parameters.c:166: -> Parameter ML_BSSN::my_boundary_condition is outdated; please update the parameter file. Do not use this parameter, and set up RHS boundary conditions as usual. cactus_sim: grille3d.C:125: Grille3d::Grille3d(int, int, int, int, int, int, int): Assertion `nr > 0' failed. Rank 0 with PID 3273101 received signal 6 For this I have attached the par file, err file, the out file (the initial data file is the one that is already there online: G2_I12vs12_D4R33T21_45km.resu.xz <https://einsteintoolkit.org/gallery/bns/G2_I12vs12_D4R33T21_45km.resu.xz>) that I am currently using. I tried to find the `nr` in the par file, but didn't find it. I am not sure if this is a MPI/num procs related problem, or is it something in the .par file that one needs to be change ? *GW150914: */Error 1 -- /Here, it is much more complicated to understand for me. This persists even after disabling |CoordinatesSymmetry::reflection_z|. Is it likely caused by coarse grid resolution relative to the number of symmetry/ghost zones. /Error 2/ -- Another error that I often encounter is File "/system/user/crangano/simulations/GW150914_28/output-0000/GW150914.rpar", line 126, in <module> sphere_outer_radius = int((outermost_detector + final_time)/(i*hr))*i*hr ZeroDivisionError: float division by zero Error: Error while executing parameter file script /system/user/crangano/simulations/GW150914_28/output-0000/GW150914.rpar Aborting Simfactory. -- I guess this occurs in the following line of the *GW150914.rpar* sphere_outer_radius=int((outermost_detector+final_time)/(i*hr))*i*hr sphere_outer_radius=int(sphere_outer_radius/hr) *hr+hr# round up to a multiple of hr So, I changed line 78 of the *GW150914.rpar as follows: * # Number of cells across finest grid radius n=int("@N@") if"@N@"[0] !="@"else28 i=max(int(n/4), 1) Is this a valid fix, or does this affect the simulations ? For this too, I attach the err, out and the par file such that you can inspect it. *Storing BSSN variables*:We would like to store the BSSN evolved *3-metric* (|γ_ij|), *lapse* (|α|), and *shift* (|β^i|) and also the corresponding coordinates (t, x^i) of these quantities at regular intervals (e.g., every 128 steps) to manage disk usage efficiently. Moreover, since AMR is used, is there any way we can keep track of the changes in resolution of the coordinates, since we also aim to do spatial derivatives via our FD stencils -- Jacobians and Hessians of these quantities. If there are ways to directly dump the Jacobians and Hessians of these quantities (by adding lines on the par file), w/o us implementing (since we are not aware of the AMR being used at different regions to implement our FD stencils), that would be very useful too. IOHDF5::out_vars = " ML_BSSN::ML_metric ML_BSSN::ML_lapse ML_BSSN::ML_shift Grid::Coordinates{out_every=1000000000 refinement_levels={0}} ML_BSSN::ML_log_confac WeylScal4::Psi4r WeylScal4::Psi4i WeylScal4::curvIr{refinement_levels={3 5}} WeylScal4::curvIi{refinement_levels={3 5}} WeylScal4::curvJr{refinement_levels={3 5}} WeylScal4::curvJi{refinement_levels={3 5}} " I would appreciate guidance on the proper way to quickly resolve these errors. Ideally, we don't need something very specific -- Just want to get these simulations running with minimum tweaking, given that these are tested gallery example and more importantly store the time-evolved metric, lapse and the shift for both these usecases. Thanks a lot in advance for your help! If you need anything do let us know. Best regards, Sandeep

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Agenda for Thursday's Meeting
by users＠einsteintoolkit.org 15 Sep '25

15 Sep '25

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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Einstein Toolkit Meeting Reminder
by users＠einsteintoolkit.org 10 Sep '25

10 Sep '25

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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KITP program in fall 2026
by Philipp Moesta 09 Sep '25

09 Sep '25

Dear everyone, We are currently organizing a KITP workshop which is scheduled to take place in the fall next year (Oct 26-Dec 18 2026): Enigmatic Explosions: Observations, Modelling, and Microphysics of Extreme Transients. The workshop will gather researchers interested in time-domain astronomy, nuclear and neutrino physics, as well as computational and theoretical modeling of mergers, supernovae, and other extreme astrophysical events. We would like to encourage interested members of the ETK community to apply to the program. The primary application deadline is Oct 24th 2025, though KITP will continue to accept rolling applications afterwards. You can find the application form here: https://www.kitp.ucsb.edu/activities/explode26 KITP generally prioritizes longer stays and we have ~27/30 spots available at any given time in the program for participants staying for 3 weeks or more, with a few participants staying for a shorter period of time. Most participants can stay at the Munger residence near campus, and KITP can provide support to participants traveling with children and dependent adults. More information on housing and family support is available here: https://www.kitp.ucsb.edu/visitors/before-your-visit If you have any questions about the program and/or application process, do not hesitate to let us know -- we hope to see many of you next year in Santa Barbara! Best, Philipp for the organizers of the workshop: Francois Foucart, Raffaella Margutti, Philipp Moesta, and Rebecca Surman Sent from Outlook for Mac

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Agenda for Thursday's Meeting
by users＠einsteintoolkit.org 08 Sep '25

08 Sep '25

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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Help with Spritz + external FUKA/Kadath
by Fatemeh Hossein Nouri 05 Sep '25

05 Sep '25

Hi all, I’ve been trying to run Spritz using initial data generated by the latest version of FUKA for a BNS simulation, but I’ve run into issues related to the Kadath libraries. At first, I was getting a mismatch error (Assertion ndim==nbr_points.get_ndim()), which suggests an incompatibility between Spritz’s bundled Kadath and the external version of FUKA/Kadath I used to generate the initial data. To fix this, I tried to build Spritz against my own external Kadath installation (~/fuka/lib/libkadath.a) instead of the one bundled in the Einstein Toolkit. I did this by disabling these thorns in my thornlist: Fuka/kadath_pizza, Fuka/KadathImporter and Fuka/KadathThorn. I also added the following lines to my ET_2024_05/Cactus/simfactory/mdb/optionlists/<machine>.cfg KADATH_DIR = $(HOME)/fuka KADATH_INC_DIRS = $(KADATH_DIR)/include KADATH_LIB_DIRS = $(KADATH_DIR)/lib One question so far: Did I do things correctly? Then I removed the old Kadath: rm -rf configs/Spritz_LORENE/build/Kadath The code compiles fine, but when I try to run the executable with my parameter file, using the '-S' option, I get: Error: Thorn kadathimporter not found Error: Thorn kadaththorn not found Activation failed - 2 errors in activation sequence The confusing part is that my ActiveThorns line in the .par file does not explicitly list KadathThorn or KadathImporter: ActiveThorns = "volomnia bnstrackergen bnsanalysis pizzanumutils" Yet Spritz fails because those thorns are missing. From what I understand, some of the thorns I’m using (like volomnia, bnstrackergen, or bnsanalysis) depend on KadathThorn and KadathImporter, so they are indirectly required. The core problem: - I need to keep KadathThorn and KadathImporter active, since my parameter file requires them through dependencies. - But I also need them to link against my external Kadath ( ~/fuka/lib/libkadath.a) so that the FUKA initial data is compatible. Would you have suggestions on the cleanest way to make the ET KadathThorn and KadathImporter use my external Kadath library? Is there a recommended workflow for this? Thanks in advance for your help! Bests, Fatemeh Nouri

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Meeting Minutes 2025-09-04
by Bill Gabella 04 Sep '25

04 Sep '25

Minutes for the Einstein Toolkit Meeting, 20250904. https://docs.einsteintoolkit.org/et-docs/Main_Page#Weekly_Users_Call 9am CDT Thursdays Present: Steve B, Deborah F, Peter D, Peyhan, Roland H, Lucas TS, Johnny T, Nikolai W, Zach E, Keith D, Bill G, Leo W Chair: Peter D Minutes: Bill G * BBH gallery example (Zach) -- not yet done (2024-11 also missing) Peter and Zach, no new work. * AOB ** Next release is in May 2026 and Steve is the release manager. https://docs.einsteintoolkit.org/et-docs/Release_Process * Unanswered emails https://www.einsteintoolkit.org/tools/unanswered.php ** No updates. * Open tickets sorted https://bitbucket.org/einsteintoolkit/tickets/issues?status=open&status=new… #2885, test for std::filesystem availability in Silo output likely broken Roland, this should not affect you if you are on a modern system. You have to look at a predefined variable and you have to use it to include the version of a file, and it is declared in those files. There is a version.h that was standardized in C++20...exists in older gcc but not standardized. In the IO code of Carpet that writes out Silo, maybe check on a file existence. Not a major issue. Was in CC_Export also, which has a recent pull request with the fix. Some bug with a static variable that depends on a function argument so it is never changed. On Deborah's to do list also. Deborah, it may not need to change. Will take a look at it. #2882, Running BBH with CarpetX with CPUs: High memory consumption and low performance Alejandra will take a look at it. #1847, FFTW3 fortran interface not working for system installation A very old ticket from Frank Loeffler. Yosef may use FFTW in his code(s). #2858, SF files for MN5 (was: Compiling CarpetX: issues with PDESolvers) Changed the name to the current one. Lucas has begun testing, thinks files very specific to Alejandra's work, on Marenostrum 5 (Barcelona). Some external libraries seem to compile themselves and put them into a folder referencing the user. Steve, not uncommon but should not had code the user directory. Lucas, that is what is happening here. On LSU machines there are directories hardcoded to Steve's directories; that is where the external libraries are, and this works. Steve, setup a system to have future checkouts and builds refer to previous compiled libraries/tools. Some external libraries take forever to compile and better to refer to some already installed library. Good to have a "benevolent user" to install these for global use. Lucas, (Marenostrum) the machine is organized into projects and allocations, and projects have an expiration date...like a DOE machine. Steve, that is awful. Lucas agrees. Lucas, think singularity would be the right thing to do, if the image is put together correctly. Peter, can you chance the setup so that they use external libraries instead of their pre-compiled ones? Lucas, have not tested with the bundles libraries. Believe they tried that and failed. Roland, you might succeed, when they tried some of the libraries did a git clone of a repositories. Lucas, Marenostrum has limitations that annoy one. Will try the bare minimum and see if that works. #2866, Problem while building the ET on MN5: OpenCL Steve disavows any knowledge of this one---name removed from ticket. This is for Marenostrum 5. [European clusters with ET include Marenostrum 5 (Barcelona), Leonardo (Bologna), and Sunrise (Stockholm).] Peter, maybe Lucas can take a look at OpenCL? Roland, we are not using OpenCL for anything now---once we had an example using it. Lucas, will try the bundled version of OpenCL and if it fails will ask them to take it out. Leaching off of Steve's Singularity image which works on LSU machines, might try for Marenostrum. #2867, WaveToyX examples, HDF5 output error in all three examples. Steve, we discuss this every wekk and the error message is considered harmless. We should close this ticket. #2773, make CarpetX-ThornDoc is confused in InterLatex.pl Steve, I need to check on that. #2878, CarpetX: Add multipatch output support to Silo Lucas, sitting and waiting for review. Not urgent. #2764, PUGH tries to free memory not allocated by malloc Beyhan, no update. #2282, gallery examples use low-order integration n Multipole Roland, part of updating. #963, Improve McLachlan accuracy Peter, will meet with Zach and work on this. #2706, Update default TwoPunctures parameters, or at least default parameters in BBH gallery example Zach, part of the BBH Gallery example and will be looked at. #2877, ET_BHaHAHA Features Ticket Zach, keep this one, I use it as a ticket to jot down ideas to improve the robustness of BHaHAHA. #2855, NoiseX: Improve noise generation in CarpetX Lucas, not worked on it for a while, intend to get back to it. #2874, NRPyElliptic lacks regeneration instructions Leo, on my list, will get back to it. Zach, you should wait on this. I plan to refactor NRPyElliptic in a library like BHaHAHA. The refactor will be a different NRPyElliptic. #2862, Update `SpacetimeX/Z4c` robust stability paramete file Lucas, that is just a parameter file update. Will review desire to include. The existing one did not work, but this one should. #2860, Don't call the optimized 4th order second derivative operators. Peter, will take a look at it. #2052, piraha assumes that assert(false) always aborts Steve, I will get to this one. * Tickets for Review https://bitbucket.org/einsteintoolkit/tickets/issues?status=new&status=open… Nothing new. Roland, no longer a ticket to backport libraries that compile with GCC 15 to earlier or to update with cmake 4.0. Applied those changes to master and release branches. Tickets #2880, #2883. *AOB at end of meeting Roland, have a CarpetX call next and Erik said he would give a presentation on mesh files. Zach, should we advertise the CarpetX call? Roland, we should list it. Will draft a description of CarpetX and give the call link. Bill, maybe we should put it down at the ET Meeting link [wiki] and not on the front web page. CarpetX wiki https://github.com/EinsteinToolkit/CarpetX/wiki CarpetX zoom https://ubc.zoom.us/j/66033196685?pwd=zxXTpcrBY1L7nT2kNFITm71ZuoZEiO.1 Next Meeting, Thursday, 11 September 2025. https://docs.einsteintoolkit.org/et-docs/Meeting_agenda FYI, bill e.g. -- Home Page <https://gabella.github.io/index.html> LinkedIn <https://www.linkedin.com/in/bill-gabella-350b016/>

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ET build errors (Leonardo DCGP, CINECA cluster)
by IOSIF PANAGIOTIS 04 Sep '25

04 Sep '25

Hi Einstein Toolkit users, I am reaching out regarding some errors I am encountering during my attempts to compile ET on the Leonardo, CINECA cluster (DCGP partition). Here are some details on the Leonardo cluster: * cluster specifics: https://docs.hpc.cineca.it/hpc/leonardo.html#leonardo-card * OS: Red Hat Enterprise Linux 8.7 I attach the 4 configuration files I am using (with many added comments for guidance and future reference). I adapted them from the respective config files that Bruno Giacomazzo kindly provided. I also attach the make.log output of the command: ./simfactory/bin/sim build --verbose --reconfig --machine=leonardo-dcgp1 --optionlist simfactory/mdb/optionlists/leonardo-dcgp1.cfg --allocation=CNHPC_1479290_0 --thornlist thornlists/einsteintoolkit.th 2>&1 | tee make.log >From what I understand, the build process complains about syntax errors in the Exact thorn in these two source files: * decode_pars.F * Boost_rotation_symmetric.F How can I bypass the above problems? To be honest, I am not sure that I really need this thorn. I was simply trying to compile ET using the default thornlist from a fresh download/installation. Is there any other error that the log file is pointing out that I might be missing? Best regards, Panayotis ------------------- Panagiotis Iosif postdoctoral researcher Department of Physics, University of Trieste Via Alfonso Valerio 2, Trieste 34127 Italy -------------------

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Einstein Toolkit Meeting Reminder
by users＠einsteintoolkit.org 03 Sep '25

03 Sep '25

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