Search Talks

Low-energy states of quantum spin liquids are thought to involve partons living in a gauge-field background. We study the spectrum of Majorana fermions of the Kitaev honeycomb model on spherical clusters. The gauge field endows the partons with half-integer orbital angular momenta. As a consequence, the multiplicities do not reflect the point-group symmetries of the cluster, but rather its projective symmetries, operations combining physical and gauge transformations. The projective symmetry group of the ground state is the double cover of the point group.

States of a CFT's subregions are consistent with a given global state. For a holographic CFT, this amounts to different entanglement wedges being patches of the same geometry. What relations between them make this possible?

I will propose a Berry experiment to study this question. Berry introduced a connection to describe transformations induced by adiabatically varying Hamiltonians. I will introduce a connection to study how the zero modes of a modular Hamiltonian are affected by varying the CFT subregion that supplies it. I will explain the geometric meaning of modular Berry phases in the bulk and describe an experiment to measure them which involves observers moving with adiabatically varying accelerations. 

In classical General Relativity (GR), an observer falling into an astrophysical black hole (BH) is not expected to experience anything dramatic as she crosses the event horizon. However, tentative resolutions to problems in quantum gravity, such as the cosmological constant problem or the black hole information paradox, invoke significant departures from classicality in the vicinity of the horizon. I outline theoretical and phenomenological arguments for these departures. I will then discuss the tentative observational evidence for Planck-scale structure near BH horizons, seen as "echoes" in LIGO gravitational wave observations,  which has now been found by three independent groups. Finally, I present preliminary analysis which strongly suggest formation of a highly spinning black hole within 0.5 second of GW170817 binary neutron star merger, based on prominent echoes in the LIGO strain data. 

Let be a complex semisimple algebraic group of adjoint type and the wonderful compacti
cation. We show that the closure in \overline{G} of the centralizer of a regular nilpotent is isomorphic to the Peterson variety. We generalize this result to show that for any regular , the closure of the centralizer in is isomorphic to the closure of a general -orbit in the flag variety. We consider the family of all such centralizer closures, which is a partial compactication of the universal centralizer. We show that it has a natural log-symplectic Poisson structure that extends the usual symplectic structure on the universal centralizer.

In this talk, I'd like to explain how quantum integrability and (q-deformed) W-algebraic structure arise from the moduli space of quiver gauge theory. It'll be also shown that our construction gives rise to a new family of W-algebras.