On threefold canonical thresholds

Abstract

We show that the set of threefold canonical thresholds satisfies the ascending chain condition. Moreover, we derive that threefold canonical thresholds in the interval $(\frac{1}{2},1)$ consists of $\{\frac{1}{2}+\frac{1}{n}{\}}_{n\ge 3}\cup \{\frac{4}{5}\}$.

arXiv comment31 pages, to appear in Advances in Mathematics