Video Lectures

Instantons are an important source of nonperturbative effects in quantum field theories, but their role in asymptotically free theories has not been well understood. In this talk, we will present a new approach to instanton analysis in the context...

The iconic spiral arms that decorate the disks of massive galaxies (like our own Milky Way) have been studied observationally and theoretically since they were first recorded 180 years ago, nevertheless the exact details of their nature remains...

I will talk about the invariants of topologically ordered states of quantum lattice systems that generalize Berry classes and can be defined for any gapped state in any dimension. The equivariant version of such invariants unifies and generalizes...

Charge-exchange (CX) collisions of the solar wind (SW) high-ionization-state minor ions with LISM neutrals are responsible for much of X-ray production in the outer heliosphere. In this talk, we discuss numerical modeling of the heliospheric CX X...

Kinematically, massless particles in Lorentz-invariant theories are classified by a dimensionful "spin scale"ρ  (2nd Casimir invariant) that characterizes helicity states' mixing under little group transformations.  However, dynamics for particles...

Interpreting observations of extreme astrophysical phenomena requires a detailed understanding of particle acceleration in astrophysical environments. These accelerated particles, known as cosmic rays, approximately follow a power-law distribution...

We discuss shockwave geometries and the connections to aspects of flat space holography. We first show how the ’t Hooft commutation relations of shockwave operators are equivalent to the commutation relation between soft and Goldstone modes familiar...

Exoplanet systems are expected to evolve with time as they age. In most cases though, the dynamical evolution of exoplanet systems over billion-year timescales are hard to observe. I'll describe how Galactic kinematics can provide accurate and...

I discuss physical motivations from black hole physics and holography for expecting finite quantum entanglement entropy in quantum gravity. I describe recent and earlier results in defining such a notion in perturbative string theory by a stringy...

The moduli space of curves, M_g, is an object of pivotal interest in mathematics and theoretical physics. Even though it has been studied with tremendous effort, little is known about its topology. For instance, the total dimension of the cohomology...