Stress-tensor OPE in N=2 Superconformal Theories

TL;DR

This paper analyzes the operator product expansion of stress-tensor multiplets in N=2 superconformal theories, deriving a universal bound on the central charge c and exploring conformal blocks for scalar primaries.

Contribution

It provides a detailed superspace analysis of the OPE in N=2 SCFTs and establishes a universal bound on the central charge c, valid across all such theories.

Findings

Derived an analytic bound on the central charge c for N=2 SCFTs.

Performed a partial conformal block analysis for scalar superconformal primaries.

Bound is saturated by the Argyres-Douglas fixed point.

Abstract

We carry out a detailed superspace analysis of the OPE of two N=2 stress-tensor multiplets. Knowledge of the multiplets appearing in the expansion, together with the two-dimensional chiral algebra description of N=2 SCFTs, imply an analytic bound on the central charge c. This bound is valid for any N=2 SCFT regardless of its matter content and flavor symmetries, and is saturated by the simplest Argyres-Douglas fixed point. We also present a partial conformal block analysis for the scalar superconformal primary of the multiplet.