2026/08/03 by Yujie Luo, Sheng Meng
Mathematics · #math.AG #math.DS #msc:14E22 #msc:14B05 #msc:37F80
26 pages, comments are welcome!
arxiv created 2026/08/03 · arxiv updated 2026/08/04
Let f:Pn\toPn be a q-polarized endomorphism, where q>1, and let Rf be its ramification divisor. We study the singularities of the ramification pair (Pn,Rf). We show that, for a general f, the pair (Pn,Rf) is log canonical. When n=2, we prove that there exists an integer s≥1 such that the log canonical threshold lct(P2;Rfs)≥1/(qs-1). The passage to an iterate is necessary in general, and the lower bound is optimal. In particular, (P2,Rfs/(qs-1)) is a log Calabi--Yau pair, completing the proof of Gongyo's conjecture for smooth projective surfaces.