Special Seminar

Speaker: Ue-Li Pen (ASIAA)
Title: Cosmological scalar helicity
Date (JST): Mon, Sep 05, 2022, 11:00 - 12:00
Place: Hybrid
Abstract: Recent reports of detections of helicity, as well as upper bounds from the 4 point function, also called parity odd modes, raises the question how such helicity could arise in the early universe. I will summarize the classification in terms of early universe fossils, present some mechanisms including helical tensor modes that generate them, their implementation in an N-body simulation, and observational prospects including galaxy spin. I will draw analogies to CMB lensing quadratic estimators, where the lensing power also forms a 4 point statistics.