Information Theoretic Inequalities as Bounds in Superconformal Field Theory

Abstract

An information theoretic approach to bounds in superconformal field theories is proposed. It is proved that the supersymmetric R\'enyi entropy $\bar S_\alpha$ is a monotonically decreasing function of $\alpha$ and $(\alpha-1)\bar S_\alpha$ is a concave function of $\alpha$. Under the assumption that the thermal entropy associated with the "replica trick" time circle is bounded from below by the charge at $\alpha\to\infty$, it is further proved that both ${\alpha-1\over \alpha}\bar S_\alpha$ and $(\alpha-1)\bar S_\alpha$ monotonically increase as functions of $\alpha$. Because $\bar S_\alpha$ enjoys universal relations with the Weyl anomaly coefficients in even-dimensional superconformal field theories, one therefore obtains a set of bounds on these coefficients by imposing the inequalities of $\bar S_\alpha$. Some of the bounds coincide with Hofman-Maldacena bounds and the others are new. We also check the inequalities for examples in odd-dimensions.