Private life of the Liouville field that causes new anomalies in the Nambu-Goto string

TL;DR

This paper investigates higher-order heat kernel terms in string theory, revealing new anomalies in the Nambu-Goto string that differ from the Polyakov string, impacting the understanding of string effective actions.

Contribution

It demonstrates how higher-order heat kernel terms induce anomalies in the string effective action, highlighting differences between Nambu-Goto and Polyakov string formulations.

Findings

Higher-order heat kernel terms cause anomalies in string actions.

Polyakov string anomalies match conformal field theory results.

Nambu-Goto string shows deviations from Polyakov results.

Abstract

I consider higher-order terms of the Seeley expansion of the heat kernel, which for smooth metrics are suppressed as inverse powers of the UV cutoff $\Lambda$, and demonstrate how they result in an anomalous contribution to the string effective action after doing uncertainties $\Lambda^{-2}\times \Lambda^2$. For the Polyakov string these anomalies precisely reproduce at one loop the result of KPZ-DDK obtained for the Liouville theory by the conformal field theory technique. For the Nambu-Goto string I find a deviation from this result which shows that the two string formulations may differ.