IAS High Energy Theory Seminar

Post-inflationary QCD axion is an attractive solution to the Strong CP problem because of the possibility to uniquely predict the axion mass if axion makes up all of dark matter. On the other hand, QCD axion models often suffer from the so-called...

String stars, or Horowitz-Polchinski solutions, are string theory saddles with normalizable condensates of thermal-winding strings. In the past, string stars were offered as a possible description of stringy (Euclidean) black holes in asymptotically...

M- and F-theory compactifications with ADE singularities give rise to non-abelian ADE gauge symmetries. The physical explanation for this phenomenon involves M2-branes wrapped on vanishing cycles. We consider an alternative approach which relies on...

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...

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...

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...

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...

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...

The spectrum of single-trace operators of order-one dimension, of holographic CFTs at strong coupling and large N, can be mapped to the spectrum of Kaluza-Klein (KK) excitations over the dual AdS supergravity solutions. Computing these KK spectra is...