Telecon Notes March 4, 2021

Attendance: Shaul, Kris, Ragnhild, Clem, Mathieu
Regrets:

Agenda:

• Update from Kris
• Commander simulations - Oslo + Clem

Notes: Shaul

• Kris gives an update on his work on low frequency foregrounds
  • unpublished evidence from Quijote for significant variation of synchrotron beta
  • Planck data for \ell>100 is dominated by noise, so we don't know the small scale structure
  • Kris has a prescription for filling in small scale structure in a non-gaussian way; reminder: PySM is gaussian fill-in, so the new procedure is interesting, but Kris is not yet saying how the filling is done.
  • Brandon mentions that people (e.g. Clark) suggest using HI data. Kris says he is not using HI data.
  • Discussion of \ell relevance: agreement that this is all relevant for lensing reconstruction at high \ell, not for low \ell data. MR points out that there is an indirect effect: averaging of small scales to larger patches will impact the large angular scale data as well.

• Clem understands the reservations HK has regarding the signal. Simulations will need to be done with higher resolution. He is more puzzled about the noise issues.