People present:

Christopher Evans, Helvi Witek, Peter Diener, Steven Brandt, Roland Haas, Zach Etienne, Maria Babiuc, Geraint Pratten

Chair: Zach Etienne

Minutes: Maria Babiuc

Zach Etienne opened the meeting.

• The first order on the agenda: official ETK representation at the Advances in Computational Relativity workshop to be held at Brown University, Sep 9 - Dec 11, 2020. 
  • Zach will attend Oct 5-9, 2020. 
  • Pieter Diener will be there at the opening and, although will give a talk on self-force, can act as ETK representative. Sep 14-18, 2020. 
  • Other ideas on how to make ETK representation more official: add a logo to the talks (Zach), wear T-shirts with the logo (Steve). 
  • The program is not out yet, but Hevli, who is in the Committee for Math and Computational Approaches, and the scientific organizer of one of the weeks, suggested including ETK in one of the discussion sessions, as a platform for modeling techniques relevant to LISA and LSC.  

• Second, was discussed the status of the CT_MultiLevel tests on macOS. 
  • Maria confirmed that tests run fine on macOS Mojave with homebrew. 
  • Zach mentioned he has a student who might be able to check the status of the tests on Catalina. 
  • Maria will contact Ian Hinder to find out how many ETK mac users are relying on macport.  
• Zach advanced to the third item on the agenda, namely unanswered question on mailing list and remarked that Roland is doing a terrific job in answering any questions that arise from all users. The then moved to open tickets and tickets in review. 
  • Roland had no new ticket to report, and mentioned that the reason why tests hang on two Virtual Machines running on a MacOS 8G laptop is that too little memory is allocated to each machine, and consequently they run out of memory. The fix is to make sure memory doesn't get allocated. 
  • One other ticket Zach mentioned is that supermike fails to compile with intel, due to an internal conflict between the new c++ compiler and previous gcc versions. Peter mentioned that ETK runs with simfactory on supermike2. Zach and Peter agreed to close the ticket. 
  • Next Zach asked and was granted the request to assign tickets to people that volunteer.
• Next, Zach opened the conversation on the BaikalETK code, namely on how to deal with steering parameters run-time vs compile-time, run-time being more convenient for users. 
  • Zaxh proposes 2 new thorns: BaikalVac and BaikalTmunu, implementing finite difference up to 8th order, with two kernels and more robust options for IllinoisGRMHD. Helvi agreed, as being more manageable for users. 
  • Roland mentioned of possibly two more copies of the thorn in the future, to support Llama and CCZ4. 
  • As future work, Zach had the idea to link scalar fields with Baikal as well. It followed a conversation between Zach and Helvi regarding the usefulness of public codes modeling scalar fields. The name of Katie Wright was mentioned, who developed a purely SENR-based scalar field code.
• With this all items on the agenda were addressed. Steve wished Zach Happy Birthday!
  • Roland mentioned that testing ETK on Mac is still open to discussion. 
  • Maria generated visualization for her run on the binary neutron star example and the will check for differences with the data from the ETK Gallery. 
  • She will open a ticket to request more explanation on the initial data used.
• Lastly, Helvi requested an update of the chair/minute taker schedule for the next month. A discussion followed, then Zach updated the web page https://docs.einsteintoolkit.org/et-docs/ET_tasks_rota to reflect the updated schedule. 
  

Zach closed the meeting.

Happy Birthday, Zach!