WI Seminar with Andrew Long

ABSTRACT:  The phenomenon of cosmological gravitational particle production (CGPP) occurs during and after inflation as quantum fields “feel” the cosmological expansion and are excited out of their ground state.  CGPP is a compelling and minimal explanation for the origin of dark matter, which might only interact gravitationally, as well as other cosmological relics.  In this talk, I’ll provide a general introduction to CGPP and then focus on our study of CGPP for massive spin-2 particles.  I’ll briefly discuss the embedding of massive spin-2 particles into the framework of bigravity, present our results for the spectrum of gravitationally produced particles, and discuss a related by-product of our analysis: an FRW-generalization of the Higuchi bound (ghost-avoidance of massive gravity on dS backgrounds).  

BIO:  Dr. Andrew Long is an Assistant Professor of Physics and Astronomy at Rice University in Houston, Texas.  His expertise is in the domain of theoretical elementary particle physics and cosmology, and his interests include physics beyond the Standard Model, dark matter, cosmological inflation, topological defects, and cosmological phase transitions.  An overarching theme of Dr. Long's research activities is to understand how we can learn about the first fractions of a second after the Big Bang by discovering the cosmological relics that remain behind in the universe today.