State of the Universe

E and B modes of the CMB y-type spectral distortions: Polarised kSZ effect

by Mr. Aritra Gon (TIFR, Mumbai)

Friday, September 9, 2022 from to (Asia/Kolkata)
at A304 and Zoom : Meeting ID: 825 1295 6967 Passcode: 384194
We analyse the secondary E and B mode polarisation of the CMB originating from the transverse peculiar velocity of free electrons, during the reionisation and post-reionisation eras. Interestingly, the spectrum of this  polarised kSZ effect can be decomposed into a blackbody part and a y-type distortion. The y-distortion part is distinguishable from the primary E and B modes and also the lensing B modes. Furthermore, it is also differentiable from the other y-type signals, such as the thermal SZ effect, which are unpolarised. We show that this signal is sensitive to the reionisation history, in particular to how fast reionisation happens. The E and B modes of y-type distortion provide a way to beat the cosmic variance of primary CMB anisotropies and are an independent probe of the cosmological parameters.