Twist operators and other conformal defects

by Marco Meineri (Perimeter & SNS Pisa)

Monday 7 Dec 2015, 11:00 → 12:00 Europe/Zurich

4/2-011 - TH common room (CERN)

The computation of the Rényi entropies in a QFT can be performed in principle using the so-called replica trick. In turn, the replica trick can be described as the insertion of a co-dimension two twist operator in the path-integral. I will focus on conformal field theories in the vacuum state, where the twist operator can be interpreted as a conformal defect, with the usual set of CFT data attached to it. Deformations of the defect are captured by the insertion of a local operator, and the shape dependence of Rényi and entanglement entropy in even dimensions has the structure of a defect anomaly. This opens the possibility of applying the bootstrap program to the study of entanglement in CFT. Along the way, I will review some general features of conformal defects.