Found 2 result(s)

### 18.01.2017 (Wednesday)

#### Holographic Entanglement Entropy for the Gravitational Anomaly in Four Dimensions

Regular Seminar Jeff Murugan (Cape Town U.)

 at: 16:30 QMWroom G.O. Jones 610 abstract: We compute the holographic entanglement entropy for the pure gravitational anomaly in 3+1 dimensions. Using the perturbative method developed for com- puting entanglement entropy for quantum field theories, we also compute the parity odd contribution to the entanglement entropy of the dual field theory that comes from a background gravitational Chern-Simons term. We find that, in leading order in the perturbation of the background geometry, the two contribu- tions match except for a logarithmic divergent term on the field theory side. We interpret this extra contribution as encoding our ignorance of the source which creates the perturbation of the geometry.

### 01.06.2016 (Wednesday)

#### Non-abelian particle-vortex duality

Regular Seminar Jeff Murugan (University of Cape Town)

 at: 14:00 ICroom H503 abstract: Quantum field theories in (2+1)-dimensions exhibit a beautiful property known as particle-vortex duality. It relates, in a precise way, two different excitations on the plane, the familiar particle-like excitations that arise from quantisation of the field and vortices, solitonic-excitations defined by the winding of a local order parameter. Originally studied in the context of anyonic superconductivity and Neilsen-Olesen vortices, extensions of the duality have recently found application to, for example, topological quantum matter. I will review some of these developments and show how recent progress in understanding non-abelian T-duality can be used to define a non-abelian particle-vortex duality in (2+1)-dimensions.