Video Lectures

Classical random walks have long served as useful intuition for the dynamics of light scalar fields in de Sitter space. This description can be shown to arise from QFT on a fixed dS background, via RG flow. The RG approach also permits corrections...

Do typical black hole microstates have semiclassical interiors? I will present a constructive approach to this question, where we prepare ensembles of black hole interiors with long wormholes using Brownian matter sources. Evaluating the frame...

The path integral of pure 3D gravity is formulated on a finite region of spacetime, with boundary conditions that fix dihedral angles or geodesic lengths. This amplitude calculates statistics of black hole matrix elements in the dual CFT. The fixed...

It has recently been understood from several points of view that the Hilbert space of quantum gravity in a closed universe has dimension one.  It has also been argued that this problem can be ameliorated by explicitly including the observer in the...

Supermassive black hole mergers are extraordinary cosmic phenomena characterized by their immense energy release, producing gravitational waves that can rival the total light output of all stars in the universe within a short time frame. These...

I will review the Penrose and Wall singularity theorems and describe their limitations. Following Shahbazi-Moghaddam, I will argue that semiclassical gravity in the infinite species limit becomes an exact theory whose metric is defined on all scales...

Not much is known about what happens at the end of black hole evaporation. Pushing the semi-classical evolution well beyond its regime of validity suggests that the final Cauchy slice breaks into a piece that remains behind the event horizon...

Last week we defined the Linial--Meshulam model for random 2 dimensional simplicial complexes and discussed two notions of connectivity for it: Vanishing of its 1st cohomology with F2 coefficients, and vanishing of its fundamental group. This time...