Astrophysics

Redshifted 21cm emission from neutral hydrogen is rapidly becoming one of our most powerful observables in cosmology. With it, we can study the evolution of dark energy at low/intermediate redshifts, the epoch of reionization, the first stars in the...

We know of thousands of planets that orbit stars beyond our solar system. However, only a handful of these exoplanets have been directly detected via imaging. In these rare and valuable cares, the light from directly imaged planets can be spectrally...

Gravitational wave detections of merging ultracompact objects provide a completely new way to constrain a large class of dark matter models. If the dark matter consists of a rich spectrum of particles, it will generically contain channels for...

A new window into the growth and evolution of large-scale structure has opened up with the recent observations of the thermal and kinetic Sunyaev-Zel’dovich (SZ) effects. I will present ongoing work to extract SZ signals in data from the Atacama...

The Bahcall Lunch follows the astrophysics colloquium lecture. 

Most of the power from an Active Galactic Nucleus is released close to the black hole, and thus studying accretion at event horizon scales—at the intersection of inflow and outflow—is essential for understanding how much matter accretes and grows...

Gravitational waves offer a unique window for probing gravity in the most dynamical regime. In particular, the ringdown of an astrophysical black hole encodes information about the properties of the remnant and the progenitor binary. In this talk, I...

Abstract: In gravity, spacelike separated regions can be dependent on each other due to the constraint equations. I my talk, I will propose a natural definition of subsystem independence in classical gravity.  Next, I show that extremal surfaces...