On a conjecture of H. Fang, Z. Lu and K.-I. Yoshikawa

Abstract

A few years ago, Fang, Lu and Yoshikawa conjectured that a certain string-theoretic invariant of Calabi-Yau threefolds is a birational invariant. We prove a weak form of this conjecture.

arXiv commentSecond version; a mistake in the formulation of the main theorem in the first version is corrected