Speaker
Description
Topology enters in quantum in quantum field theory in multiple forms: one of the
most important being the identification of the $\theta$ vacuum in QCD.
A very relevant aspect of this connection is through the phenomenon of
the anomalies, both chiral and conformal.
It has been realized recently that a class of materials, comprising topological insulators and Weyl semimetals,
exhibit the phenomenon of anomalies, which produce several exotic phenomena in these
materials. The presence of superconducting currents, resilient under perturbations and scattering
by impurities, indeed, has been associated with the phenomenon of quantum field theory anomalies. For instance, the description of the
response functions of these materials under thermal and mechanical stress involves general relativity, and
correlation functions of stress energy tensors, therefore, play an important role in this context.
In this work we discuss local and nonlocal effective actions relevant for their quantum field theory descriptions, their consistent
definition in Dimensional Regularization, and the long-range interactions appearing in their expansion respect to the external
sources.
