I work on quantum field theory and gravity, with particular emphasis on the following three themes.
The holographic principle in quantum gravity
The holographic principle is the idea that the fundamental degrees of freedom in gravity reside at the boundary of spacetime, at infinity. In anti-de Sitter space, this idea is made precise by the AdS/CFT correspondence, where the boundary description is a conformal field theory without gravity. I study how holography can be extended beyond anti-de Sitter space, in particular to cosmological and asymptotically flat spacetimes.
Quantum field theory in curved spacetime
Quantum field theory describes elementary particles and their interactions. I study quantum fields in de Sitter space and other cosmological settings, focusing on the correlation functions that describe fluctuations in the early Universe and the information they contain about fundamental physics.
Conformal field theory
Conformal field theories are special quantum field theories that look the same no matter how much you zoom in or zoom out. They play a central role in holography and cosmological correlators, provide powerful methods for studying physical observables.