Integrated Calendar

Massive black holes, weighing millions to billions of solar masses, inhabit the centers of today's galaxies. The progenitors of these black holes powered luminous quasars within the first billion years of the Universe. The first massive black holes must therefore have formed around the time the first stars and galaxies appeared and then evolved along with their hosts for the past thirteen billion years.
I will discuss some aspects of the cosmic evolution of massive black holes, from their formation to their growth and the interplay between black holes and galaxies.

It has been argued recently that, through a phenomenon of many-body localization, closed interacting quantum systems subject to sufficiently strong disorder would undergo localization transtion and fail to thermalize. Although both the physics of the many-body localized state, as well as the ergodic state, are well understood, there is no theory for the transition between them. In this talk I will describe a theory of the many-body localization transition based on a novel real-space renormalization group approach. The method becomes asymptotically exact near the critical point, and predict the universal aspects of the transition. The results of this theory are corroborated and intuitively explained with a phenomenological effective description of the critical point and of the “badly conducting” state found near the critical point on the delocalized side.

I’ll describe how to define and compute Euclidean partition functions of 4d N=1 theories on spaces that look like a circle times a simple three manifold. These partition functions can be interpreted as supersymmetric indices: supertraces over the Hilbert space resulting from quantizing the theory on the three manifold, analogous to the Witten index. I’ll show how to calculate these indices using localization and describe some applications of the results.