Triangular Seminar Christopher Herzog (KCL)
I discuss some aspects of boundary conformal field theories (bCFTs) with an emphasis on space-time dimensions greater than two. I will demonstrate that free bCFTs have a universal way of satisfying crossing symmetry constraints. I will introduce a simple class of interacting bCFTs where the interaction is restricted to the boundary. Finally, I will discuss relationships between boundary trace anomalies and boundary limits of stress-tensor correlation functions. (Tea and biscuits + wine at the end!)
Regular Seminar Per Sundell (Andres Bello University)
We review the global formulation of higher spin gravity using topological field theory methods and non-commutative geometry and related recent progress in constructing micro states for black holes, domain walls and cosmologies.
Regular Seminar Martin Zirnbauer (University of Cologne)
room G O Jones 610
The scaling behavior near the transition between plateaus of the integer quantum Hall effect has traditionally been interpreted on the basis of a two-parameter renormalization group flow conjectured from the non-linear sigma model of Pruisken. Yet, this scaling picture never led to any analytical understanding of the critical point. Here we propose a novel description of the critical point as Pruisken's nonlinear sigma model coupled to a maximally gauged Wess-Zumino-Witten model of level 4. This proposal explains the existing numerical data for the multifractal scaling exponents of critical wavefunctions.