|Abstract: The class of Non-Linear Sigma Models NLSM in two space-time dimensions
have many interesting physical applications.
Within the path integral formulation,
forced to focus on the NLSM whose target space has Euclidean signature.
However among the
most prominent applications of the models are the description of the universality classes in disordered systems, where the requirement of Euclidean signature for the target space
which is closely related to unitarity may be too severe.
When faced with the study of a NLSM whose metric is of Lorentzian signature,
the first thing that may come to mind is to apply the Wick rotation to the target manifold similar to
the famous trick for the world-sheet. However, how would the results on
the Euclidean NLSM help in understanding its Lorentzian counterpart beyond the
scope of the classical field theory? Generally speaking, no reliable resolution is currently available.
In the talk some recent progress for
the so-called Euclidean/Lorentzian black hole NLSMs will be described
these models can be obtained by gauging the
SL2,R WZW model over the compact/non-compact one dimensional subgroup.
The results were obtained using a surprising relation between the sigma models and a certain integrable spin chain.
Link to the Event Video