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Md Arif Shaikh edited this page Mar 24, 2022 · 2 revisions

March 24, 2022

Vijay Varma, Katerina Chatziiouannou, Tousif Islam, Antoni Ramos-Buades, Arif Shaikh, Prayush Kumar, Sophie Hourihane, Harald Pfeiffer

Vijay and Harald's proposals for LVK (sorry, behind the LIGO paywall) https://dcc.ligo.org/G2200478, https://dcc.ligo.org/G2200517

Katerina: could be other definitions. Idea to explore a few approaches and see which one does best? Yes

E.g. look at Edot and Ldot, specifically Edot - Omega Ldot should be zero for quasi-circular by N-th law of BH mechanics. Then there are oscillatons on top, use amplitude for eccentricity, phase for mean anomaly

Toni: Also smooth connection bound-unbound as part of goal? Would be a good long-term goal.

Talk about whether CCE could speed up getting waveforms, so eccentricity tuning based on waveforms can be done without needing to evolve extra long to get GWs at extraction radii.

Discussion about what's the goal?

  • eccentricity as function of time
  • eccentricity at fixed time
  • .. at fixed frequency

The first is harder (more noise early, quicker evolution toward merger, more computationally expensive), and may not be highest priority.

Several voices agreeing that a local method (near one instance of time) would be a good compromise. Defining at fixed frequency is more complicated, worry about it later. E.g. by defining an average frequency and rootfinding on that. But there could be physical effects (e.g. nutation) that causes even orbit average frequencies to be non-monotonic, so f_ref could be intrinsically ill-defined ??

Test-problems:

Arif used Toni's EOB model, fixing BBH parameters (equal mass, non-spinning), plot EOB-ecc vs. GW-ecc, look for continuous behavior ("straight lines"). Repeat across parameter space.

ACTION ITEMS

  • Harald to get his code into a useful form and make it available.
  • Toni to prepare a list of SXS-IDs to use for testing.
  • Toni: to prepare some EOB waveforms in an easy-to-use format
  • Tousif: to add some RIT waveforms
  • Arif: Add a base module that could be used in all the different implementations
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