Astronomy & Astrophysics Seminar: The Cosmic Infrared Background as a window into primordial non-Gaussianity

Abstract:

In cosmic microwave background (CMB) experiments, the cosmic infrared background (CIB) produced by unresolved high-redshift galaxies is treated as a nuisance that must be subtracted from the data. In this talk, I will demonstrate that the CIB encodes interesting cosmological information and, in particular, is a sensitive probe of inflationary non-Gaussianities.

Although galactic dust dominates over the inflationary signal, I will show that it is possible to mitigate the dust contamination with enough frequency channels, especially if high frequencies such as the Planck 857 GHz channel are available. Future space missions should be able to probe the local bispectrum shape down to an amplitude | fNL | < 1. I will also illustrate how such a multi-frequency approach can be tested with synthetic maps of the microwave sky.

Seminar Organizer: Prof. Sara Beck