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Astrophysics, Gravitation and Cosmology Seminar: Measuring the Universe at microwave, infrared and gamma-ray wavelengths

Event Type
Department of Physics
222 Loomis
Oct 18, 2017   12:00 pm  
Chang Feng, University of Illinois at Urbana-Champaign
Milton Ruiz
Originating Calendar
Physics - Astrophysics, Gravitation, and Cosmology Seminar
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. In addition to these two main contributions, the B-modes could also be generated 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 flight data, an excess in measured infrared background is detected from the power spectrum at large angular scales and a new model—intrahalo light—is developed to interpret 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.
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