Talks

In order to think about the foundations of physics it is important to understand the logical relationships among the physical principles that sustain the building. As part of these axioms of physics there is the core hypothesis that, how the Universe is partitioned into systems and subsystems is a subjective choice of the observer that should not affect the predictions of physics. Other foundational principles are the Postulates of Quantum Mechanics. However, we prove that these are not independent from the “independence of subsystem partitioning” hypothesis described above. In particular, we prove that the mathematical structure of quantum measurements and the formula for assigning outcome probabilities are implied by the mentioned hypothesis and the rest of quantum postulates. 

I will review recent progress in computing the exact planar spectrum of closed strings in
AdS3 backgrounds with 8+8 supercharges, including the derivation of the protected spectrum.
Such theories have a multi-dimensional moduli space, and I will show what effect varying
the moduli has on the exact closed string spectrum, and how the integrable structure changes
as we do so, paying particular attention to the background supported by NS-NS flux.

Ultralight bosons exist in various proposed extensions to the Standard Model, which can form condensates around rapidly rotating black holes through a process called superradiance. These boson clouds have many interesting observational consequences, such as the continuous emission of monochromatic gravitational waves.  In this talk, I will describe the dynamics of the system when it is part of a binary black hole. I will show that the presence of a binary companion greatly enriches the evolution of the boson clouds, most remarkably through the existence of resonant transitions between growing and decaying modes of the clouds. Finally, I will sketch some phenomenological consequences, both for the gravitational waves emitted by the clouds and the finite-size effects imprinted in the waveforms of the binary signal.