Katherine Mack

In a special live webcast with Perimeter Institute on May 6, 2020, theoretical cosmologist and science communicator Katie Mack — known to her many Twitter followers as @AstroKatie — answered questions about her favourite subject: the end of the universe. Mack is currently a Simons Emmy Noether Fellow at Perimeter and an Assistant Professor at North Carolina State University.

While it is considered to be one of the most promising hints of new physics beyond the Standard Model, dark matter is as-yet known only through its gravitational influence on astronomical and cosmological observables. I will discuss our current best evidence for dark matter's existence as well as the constraints that astrophysical probes can place on its properties, while highlighting some tantalizing anomalies that could indicate non-gravitational dark matter interactions.

We investigate the effect of evaporating primordial black holes on the ionization history of the universe, with emphasis on limits derivable from the CMB and future 21-cm observations of high-redshift neutral hydrogen.