Astrophysics

Astrophysical black hole candidates, although long thought to have a horizon, could be horizonless ultra-compact objects. This intriguing possibility is motivated by the black hole information paradox and a plausible fundamental connection with quantum gravity. In this talk I will consider the asymptotically free quadratic gravity as the UV completion of general relativity. Using a classical theory that captures its main features, we find that sufficiently dense matter produces a novel horizonless solution, the 2-2-hole. It closely matches the exterior Schwarzschild solution down to about a Planck proper length of the would-be horizon. I will describe interesting features of the 2-2-hole and various physical implications. As a generic static solution, the 2-2-hole may be the nearly black endpoint of gravitational collapse.

CHIME is a new interferometric telescope at radio frequencies 400-800 MHz.  The mapping speed (or total statistical power) of CHIME is among the largest of any radio telescope in the world, and the technology powering CHIME could be used to build telescopes which are orders of magnitude more powerful.  This breakthrough sensitivity has the power to revolutionize radio astronomy, but meeting the computational challenges will require breakthroughs on the algorithmic side.  I'll give a status update on CHIME, with an emphasis on new algorithms being developed to search for fast radio bursts and pulsars.