SB/BNL Joint Cosmo seminar (at Stony Brook): Chang Feng, U of Illinois: Measuring the Universe at microwave, infrared and gamma-ray wavelengths

Wednesday 11 Oct 2017, 13:30 → 14:30 US/Eastern

Universe

CMB B-mode polarization observations of the primordial gravitational wave signal provide a powerful probe of the inflationary universe, and the small-scale lensing B-modes also give an accurate integrated measure of large-scale structure out to high redshift along the line of sight. However, the B-modes generated by inflationary gravitational waves could be contaminated by other sources, such as cosmic birefringence and primordial magnetic fields. For a few years, POLARBEAR is putting together large telescopes with sensitive detectors to target the faint B-mode signal. The first results confirming the existence of lensing B-modes have been published, but further progress will require significant improvements both in instrumentation and data analysis technique. In a search for signatures from first stars and galaxies, CIBER is a rocket-borne instrument that can probe the absolute spectrum and spatial anisotropy of the extragalactic infrared background. From the recent three flights, an excess of measured infrared background is detected and a new infrared source--intrahalo light--which can fit the data very well, is thought to be the origin of the excess. At gamma-ray wavelength, we use the Fermi-LAT data in conjunction with Planck data sets to constrain dark matter signatures in the gamma-ray background anisotropies.