Boundary Condition Changing Operators in Conformal Field Theory and Condensed Matter Physics

TL;DR

This paper reviews boundary condition changing operators in conformal field theory, connecting them to condensed matter phenomena like the X-ray edge singularity, and extends the formalism to include bound states and finite-size effects.

Contribution

It provides a general derivation linking the X-ray edge singularity, Anderson orthogonality catastrophe, and finite-size scaling, along with extensions to include bound states.

Findings

Derived a connection between X-ray edge singularity and finite-size scaling.

Extended the formalism to incorporate bound states.

Reviewed boundary condition changing operators in condensed matter physics.

Abstract

Boundary condition changing operators in conformal field theory describe various types of "sudden switching" problems in condensed matter physics such as the X-ray edge singularity. We review this subject and give two extensions of previous work. A general derivation of a connection between the X-ray edge singularity, the Anderson orthogonality catastrophe and finite-size scaling of energies is given. The formalism is also extended to include boundstates.