Loop Corrections to the Universal Hypermultiplet

TL;DR

This paper investigates one-loop quantum corrections to the moduli space of the universal hypermultiplet in string theory compactifications, revealing a correction proportional to the Calabi-Yau's Euler characteristic that vanishes at infinite Planck mass.

Contribution

It demonstrates that the universal hypermultiplet's moduli space receives a one-loop correction linked to the Calabi-Yau's Euler number, which can be absorbed by a field shift.

Findings

One-loop correction proportional to Euler character.

Correction vanishes as Planck mass approaches infinity.

Correction is gravitational in origin.

Abstract

The universal hypermultiplet arises as a subsector of every Calabi-Yau compactification of M-theory or Type II string theory. Classically its moduli space is the quaternionic space $SU(2,1)/U(2)$. We show that this moduli space receives a one-loop correction proportional to the Euler character of the Calabi-Yau, which can locally be absorbed by a certain constant shift of the fields. The correction vanishes in the limit that the Planck mass is taken to infinity, and hence is essentially gravitational in nature.