| 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. |
