Astrophysics Seminar: Odd Parity in the CMB and Stringy Topologies

Abstract:

If inflation was relatively short, signatures of pre-inflationary physics could be observed at the largest scales. These scales, for which the cosmic variance is large, indeed show several anomalies, such as isotropy breaking and lack of power. In this talk I will describe one such anomaly, the odd parity of the CMB. The test for anomalous large scale parity finds a direction which exhibits odd parity under reflections through the normal plane, anomalous at a ~3.6 sigma level. One class of models that can affect the largest scales is a non-trivial topology of the universe. It can lead to interesting symmetries in the CMB that we can search for in the data. I will consider some non-classical topologies, allowed by string theory, and describe their observational signatures and the searches for these signatures in the CMB data.

Seminar Organiser: Prof. Rennan Barkana