Users March 2021

users@lists.einsteintoolkit.org

19 participants
28 discussions

CarpetX First Steps
by Erik Schnetter 21 Mar '21

21 Mar '21

Following up on last week's CarpetX tutorial, I have written up instructions for downloading and building CarpetX in the README at <https://bitbucket.org/eschnett/cactusamrex>. -erik -- Erik Schnetter <eschnetter(a)perimeterinstitute.ca> http://www.perimeterinstitute.ca/personal/eschnetter/

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CarpetX tutorial
by Steven Brandt 18 Mar '21

18 Mar '21

Thanks again to Erik for presenting the first official CarpetX tutorial. You can find the recording here: https://lsu.zoom.us/rec/share/YcrCqkVkEZ5BjqZrXQa-vt7EOGyXFL8rD26-GASPOEhSY… Also, inside the cactusamrex repo, there are dockerfiles to create a working CarpetX image. You can find the working image at this location on dockerhub: einsteintoolkit/cactus-amrex-jovyan Invoking "build.sh" inside the image should check out (using GetComponents) and build Cactus with CarpetX. --Steve

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Einstein Toolkit Meeting Reminder
by users＠einsteintoolkit.org 17 Mar '21

17 Mar '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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reminder: presentation on CarpetX by Erik Schnetter on March 18th 2021in the ET call slot
by Roland Haas 17 Mar '21

17 Mar '21

Hello all, This Thursday Erik Schnetter will present how to user CarpetX, the next generation mesh refinement driver for the Einstein Toolkit which is based on AMReX. CarpetX is developed as part of the Einstein Toolkit and can be found at: https://bitbucket.org/eschnett/cactusamrex In the interest of time, this presentation will not contain any hands-on parts, however the developers will be available to help interested users setting up CarpetX on their own at a later time. Yours, Roland -- My email is as private as my paper mail. I therefore support encrypting and signing email messages. Get my PGP key from http://pgp.mit.edu .

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Agenda for Thursday's Meeting
by users＠einsteintoolkit.org 15 Mar '21

15 Mar '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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update LORENE version within ExternalLibraries
by Bruno Giacomazzo 14 Mar '21

14 Mar '21

Hi, the versions of LORENE available within the Einstein Tollkit (both LORENE and LORENE2) are pretty old and they also include a few bugs that have been fixed in the current version of the LORENE library available on https://lorene.obspm.fr/ Would it be possible to add the current version of LORENE to the Einstein Toolkit? I was really happy when LORENE was included within the Einstein Toolkit (it made my life much easier), but unfortunately the version within the Toolkit is not usable anymore, especially when working with tabulated EOS (in particular with the CompOSE format, but not only) and new initial data. In the case of Spritz for example, we have to compile LORENE separately (see the comment on https://zenodo.org/record/4350072) and it is sometimes a bit of a hassle to get it linked correctly with the Cactus executable (especially when moving to new clusters). Thanks, Bruno P.S.: btw, I was not able to find which version of LORENE the thorns LORENE and LORENE2 refer to. I think LORENE2 is from 2015, but I'm not 100% sure. -- Prof. Bruno Giacomazzo Department of Physics University of Milano-Bicocca Piazza della Scienza 3 20126 Milano Italy email: bruno.giacomazzo(a)unimib.it phone: (+39) 02 6448 2321 web: http://www.brunogiacomazzo.org ---------------------------------------------------------------------- There are only 10 types of people in the world: Those who understand binary, and those who don't ----------------------------------------------------------------------

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parsing bug for temperature_evolution_method
by Hee Il Kim 11 Mar '21

11 Mar '21

Dear all, I have encountered a bug in using HydroBase::temperature_evolution_method. If it is given explicitly by taking its default value "GRHydro", my runs crashed while reading a Lorene data. But if it's not given in the parameter file, it run smoothly but the results are the same with the case of taking "none". I found this bug when I was testing Hybrid EOS. I've tried to realize pure Polytrope (or Ideal_Fluid) by using the piecewise Hybrid EOS interface. But the results are showing around 10% more variations in rhomax compared to the pure Polytrope/Ideal_Fluid cases. I'm using Turing version. Thanks for you help in advance. Hee Il

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Meeting Minutes 2020-03-11
by Miguel Gracia 11 Mar '21

11 Mar '21

Present: Erik S, Atul K., Lorenzo E., Peter D., Bruno G., Kenneth S., Miguel G., Leonardo M., David B., Roland H., Federico L., Steven B., Zach E. Chair: Steven B, Minutes: Miguel G. • Updating LORENE version in ET ticket<https://bitbucket.org/einsteintoolkit/tickets/issues/2206/make-lorene2-the-…> email<http://lists.einsteintoolkit.org/pipermail/users/2021-March/007836.html> [Bruno Giacomazzo] [Bruno G]. LORENE Thorn is not updated with the 2018 version of LORENE. ET compilation fails when trying to compile it with the 2018 LORENE version, this is because the ET patches cannot be applied because LORENE source code is different. [Bruno G]. LORENE 2018 version fixes bugs related with tabulated EOSs. [Bruno G]. Asked if there’s some step by step tutorial about how to create LORENE thorns. [Eric S] Frank L. created LORENE2 tarball. [Steven B.] is going to ask Frank L. to provide some sort of documentation. [Roland H.] Recommended Bruno to use LORENE2 and report back if he is able to make it work with the 2018 LORENE version. if not it needs to be patched like any other external libraries. (see ticket<https://bitbucket.org/einsteintoolkit/tickets/issues/2206/make-lorene2-the-…>) • SPEC benchmark contribution task [RH, SB]. https://bitbucket.org/einsteintoolkit/tickets/issues/2470 [RH] waiting for response. * Unanswered questions / Open tickets / tickets ready to review -Termination trigger feature request. RH thinks it would be useful feature, thinks it is easy to add. Steven B. is going answer the email and ask the author to make a pull request. -no comments about tickets open/ready to review. * ET Release update: [Zach E.] We have one new feature POWER, not yet in Master, waiting for the reviewer…by mid May,code reviews must be finished. * Other comments/discussion: Simfactory3 passed the Test,<https://build-test.barrywardell.net/job/SimulationFactory/> user Albert pw Einstein [Atul K.] Clarified the mailing list question by Hee Il (parsing bug for temperature_evolution_method) answered by Roland (email<http://lists.einsteintoolkit.org/pipermail/users/2021-March/007842.html>). [Roland H.] Try to use only equation of states that doesn’t use temperature like tabulated ones . -Reminder On March 18 (usual ET call time), We have a CarpetX tutorial by Eric S. Will be focused on writing thorns and how to translate existing thorns from Carpet to CarpetX. Everything from a simple user perspective. Future chair and minute takers: March 25 Chair: Roland H. Minute taker: Steven B. end of the meeting. ——

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Einstein Toolkit Meeting Reminder
by users＠einsteintoolkit.org 10 Mar '21

10 Mar '21

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Can I simulate this exotic static topological spacetime with the ET?
by Adam Herbst 08 Mar '21

08 Mar '21

Hi all, Before tackling the learning curve, I want to see if there's any chance I can do what I'm hoping to, because it seems unlikely, but with something as highly developed as the ET appears to be, you never know! I want to find a stationary spacetime, in which each time-slice has a topological defect anchored at the origin. Specifically, we take an "extruded sphere" (S^2 x [0,1]), set the metric such that the radii of the end-spheres goes to zero, and attach each end to one "half-space" of the origin (theta in [0, pi/2] and theta in [pi/2, pi]). This can be done "smoothly" by having g_{theta,theta} from outside approach sin^2(2 * theta) instead of sin^2(theta), so that a radial cross-section becomes a pair of spheres, one for each half-space, instead of a single sphere. Thus the defect is actually a "bridge" between these two half-spaces, and geodesics through the origin traverse this loop. But the curvature does become infinite at the origin. Now the thing is, what I really want to do is start with the ansatz described above (I already have a formula for the metric), and make it converge to a solution of the Einstein-Hilbert action, while keeping it stationary. But in this case it is NOT the same as the vacuum field equation, because the "boundary condition" of the topological singularity will not allow the Ricci curvature to disappear, even when we minimize total curvature. Or so I believe. So that's why it has to be a purely action-based approach, if that even makes sense. So I hope this was coherent. And if it is possible, can you let me know which modules I should start getting familiar with in order to give it a shot? Thank you for reading! Cheers, Adam

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Users March 2021