This event has passed.

SPECIAL RPM-Berkeley Cosmology Seminar | Anton Baleato Lizancos (University of Cambridge) “Fundamental Physics with CMB Lensing and Delensing: the Good, the Bad and the Systematics”

February 2, 2021 @ 1:10 pm - 2:10 pm

Abstract:

Gravitational lensing of CMB photons by the matter distribution of the Universe can be both a blessing and nuisance. It’s a blessing because of the way it can be harnessed to map the structures responsible for the deflections, and from this, constrain any physics affecting the growth of cosmic structure, such as the sum of the neutrino masses or dark matter. But lensing is also a nuisance because it generates B-mode polarization which obscures the highly-sought-after primordial signal associated with gravitational waves generated during cosmic inflation, our most accessible portal to physics near the GUT scale. In this talk, I will focus on key systematic effects that need to be controlled in order to harness the full potential of the Simons Observatory (SO), CMB-S4, and other upcoming experiments to make progress in these exciting areas.

In the first part of my talk, I will briefly review the ways in which emission from galaxies and clusters can bias power spectra and cross-correlations of CMB lensing reconstructions, and describe our ongoing efforts to understand these biases analytically. Then, in the second part, I will explain how the lensing contamination to CMB B-modes can be removed — what is known as delensing — and discuss our recent findings regarding the performance of different delensing methods. I will also summarize preparatory work to delens SO data, and highlight biases to watch out for (and how to mitigate them) when the matter proxy used for delensing is either the cosmic infrared background or a lensing reconstruction derived from the CMB itself.

──────────
Troy Cortez is inviting you to a scheduled Zoom meeting.

Join Zoom Meeting
https://lbnl.zoom.us/j/95317538825

Meeting ID: 953 1753 8825
One tap mobile
+16699006833,,95317538825# US (San Jose)
+13462487799,,95317538825# US (Houston)

Dial by your location
+1 669 900 6833 US (San Jose)
+1 346 248 7799 US (Houston)
+1 253 215 8782 US (Tacoma)
+1 312 626 6799 US (Chicago)
+1 646 558 8656 US (New York)
+1 301 715 8592 US (Washington D.C)
Meeting ID: 953 1753 8825
Find your local number: https://lbnl.zoom.us/u/acS28Unfh8

Join by SIP
95317538825@zoomcrc.com

Join by H.323
162.255.37.11 (US West)
162.255.36.11 (US East)
115.114.131.7 (India Mumbai)
115.114.115.7 (India Hyderabad)
213.19.144.110 (Amsterdam Netherlands)
213.244.140.110 (Germany)
103.122.166.55 (Australia)
64.211.144.160 (Brazil)
69.174.57.160 (Canada)
207.226.132.110 (Japan)
Meeting ID: 953 1753 8825

──────────

Details

Date:: February 2, 2021
Time:: 1:10 pm - 2:10 pm
Website:: https://lbnl.zoom.us/j/95317538825

Venue

: Zoom Talk
: 50A-5132
Berkeley, ca 94720 + Google Map