Users July 2012

users@lists.einsteintoolkit.org

18 participants
30 discussions

Einstein Toolkit 2012 Paper NS gravitational collapse example
by Vassilios Mewes 24 Jul '12

24 Jul '12

Hello all, i have a few questions regarding the example of a collapsing NS from the recent Einstein Toolkit paper... in figure 19, the evolution of the radius of the NS is shown, alongside with the appearance of the Apparent horizon... the plot shows the evolution up to a time of roughly 180 (in M_sun)...my first question is: for how long in total was the simulation running? for how much longer is the evolution stable AFTER the BH has been formed? does the code eventually crash or was there only interest in showing the successful collapse and then stop the simulation manually after that point? furthermore, in the tov_collapse_vc_l3.par file for the collapse for the paper there the following parameters for a thorn *corecollapsecontrol* the following section: *corecollapsecontrol::rho_max_list[0] = 2.5e15* *corecollapsecontrol::rho_max_list[1] = 3.5e15* *corecollapsecontrol::check_every = 64* * * *corecollapsecontrol::rho_max_every = 16* *CoreCollapseControl::handle_PMR = yes* *CoreCollapseControl::output_control = no* *CoreCollapsecontrol::bounce_rho = 2.0e33* *corecollapsecontrol::bounce_criterion = "density"* *corecollapsecontrol::bounce_entropy = 3.0e0* what is this *corecollpasecontrol* thorn doing? and where can it be obtained if it is necessary for successful simulations of NS to BH collapse? best wishes, Vassili

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GetComponents strange behaviour
by Luca Baiotti 23 Jul '12

23 Jul '12

Hello, I used GetComponents with my thornlist to checkout a Cactus tree. Then I modified the thornlist, entered into the directory Cactus and run bin/GetComponents --root=../20120705.th (without the --update option) The unexpected result is that this time the specified thornlist is not read. Instead, GetComponents uses the original thornlist, probably stored somewhere (where?). Is this behaviour intended? Cheers, Luca

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BLAS/LAPACK library name in ranger-intel11.cfg
by Bruno Coutinho Mundim 23 Jul '12

23 Jul '12

Hi, BLAS/LAPACK libraries are referred in ranger-intel11.cfg simfactory option list as: BLAS_LIBS = -mkl LAPACK_LIBS = -mkl Is this really correct? Should the dash be there? I haven't tested yet but I would set it without the dash: BLAS_LIBS = mkl LAPACK_LIBS = mkl Any thoughts? Thanks, Bruno.

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meeting minutes
by Roland Haas 23 Jul '12

23 Jul '12

Present were: Yosef, Josh, Ian, Eloisa, Tanja, Erik, Steve, Peter, Roland ET fall workshop: * dates: for about 1 week between Oct 22nd and Nov 5th * location: RIT * topics: ** MHD ** efficiency/scaling ** scheduler improvements, (reads/writes, task based scheduling, simplifying time/refinement level handling) ** generic elliptic solver ExternalLibraries: * ensure that all libraries exclude the same list of system libraries (that eg. HDF5 does) * cannot specify (only) full path since some libraries (LORENE) will themselves use -L * Ian reports that the tests pass with the new MPI method using ExternalLibraries on both the test system and his mac laptop LSU server woes: * was caused by a configuration error for the external DNS server * is working now ET webpage: * list of publications using ET (http://einsteintoolkit.org/publications/) is out of date * would like either automated system to collect papers based on whether the reference the ET paper or that extracts specially tagged entries from master bibtext file at https://svn.einsteintoolkit.org/manifest/trunk/einsteintoolkit.bib * poll authors regularly (3months interval) to report new papers on the users list * we have a list of all Cactus-using papers in the CIGR renewal grant proposal (the citeUS entries). See http://www.tapir.caltech.edu/~rhaas/cactususers.bib * need volunteer to collect information, produce web-page Yours, Roland

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CCP2012: invited speakers & early bird registration (deadline July 31st)
by Luca Baiotti 22 Jul '12

22 Jul '12

Dear all, again, I would like to invite you all to the Conference on Computational Physics 2012 (CPP2012) that we are organising in Kobe (Japan), October 14 (Sun) - 18 (Thu), 2012. The list of invited speakers has been completed: http://www.ile.osaka-u.ac.jp/CCP2012 Our goal for CCP2012 is to encourage strong communication among different fields, and to foster new collaborations between fundamental research and applications, through the commonality of numerical methods. In particular, we arranged several parallel sessions on the basis of numerical methods, with contributions in each session from different fields of physics and related subjects. Please forward this invitation to anyone who may be interested. I hope to see you all in Japan. Luca Baiotti Osaka University *** additional NOTES on CCP2012 *** The Conference on Computational Physics is held every year under the auspices of the International Union of Pure and Applied Physics (IUPAP). In 2012 the CCP will be organized in Japan and will coincide with the opening of the K-computer (presently ranked second of the TOP500) for shared use.

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Einstein Toolkit Meeting Reminder
by Roland Haas 22 Jul '12

22 Jul '12

Hi Please consider joining the weekly Einstein Toolkit phone call at 10 am US central time on Mondays. As usual, you can find instructions how to join on the following web site: http://einsteintoolkit.org/community/support/ In short: the number is (+1) 225-578-4942 or (+1) 866-573-0359 and the conference id is 118682#. I will host this week's call, so hopefully everything will go smoothly. Roland Haas

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einsteintoolkit.org unreachable
by Roland Haas 20 Jul '12

20 Jul '12

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hello all, right now if I (or Christian Ott who pointed this out) do a ping to einsteintoolkit.org, I get: rhaas@horizon:~$ ping www.einsteintoolkit.org ping: unknown host www.einsteintoolkit.org Is the server down? Pinging cct.lsu.edu works fine. 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://keys.gnupg.net. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAlAJ/XIACgkQTiFSTN7SboXHRQCfaN9/zZIL3OuB84bgJq5zfAxW akYAn0CUxxDOfnNSMQ77lE/VXygOnJN3 =aIo0 -----END PGP SIGNATURE-----

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coordinate systems
by Comer Duncan 19 Jul '12

19 Jul '12

Hi, I am wondering exactly which (common) coordinate systems are 'deeply' supported in Cactus? These days of course most use Cartesians. I think I see reference to spher3D in various places but am not certain the extent to which spherical coords are fully supported. Also, I see no mention to cylindrical coordinates. So, I am asking for guidance about just what is the breadth of common 3D coordinate system support. Can you please let me know? Thanks very much. Comer

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AHFinderDirect?
by Petr Tsatsin 19 Jul '12

19 Jul '12

Hello, I'm trying to use AHFinderDirect in the simulation of the NSs merger and was wondering if somebody can suggest how to set up the parameters for this thorn? More precisely I simulate two neutron stars tracked by moving grids. I can evolve this until merger and simulation fail once BH horizon has formed. I would like to use AHFinderDirect to look for a AH. Particularly I have a several questions: 1) Do I need 3 centres of refinement in order for AHFinder to work? By 3 centres I meant 2 moving grids and one stationary at the origin. (I just looked at qc0 parameter file as an example) 2) What's going to happen with a 2 moving grids when apparent horizon was formed? Since I use maximum density tracking mechanism to track the positions of the NSs I want to switch the moving grids off after the formation of the apparent horizon and have only one centre of refinement at the origin. I was wondering if somebody had an experience in this type of simulations and would be willing to share it. I would really appreciate any suggestions and help. Thank you. -- Petr Tsatsin Graduate Student - Department of Physics Charles E. Schmidt College of Science Florida Atlantic University (561)-297-3386 cell: 561-692-2040 ptsatin(a)fau.edu, ptsatsin(a)gmail.com

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meeting minutes
by Roland Haas 16 Jul '12

16 Jul '12

Present were: Roland, Yosef, Peter Since there was no agenda and only three of us showed up, we decided to not have reached quorum and end the meeting early. Yours, Roland [1] http://einsteintoolkit.org/documentation/contribute/

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Users July 2012