On a connectedness principle of Shokurov-Kollr type

作     者：Christopher D.Hacon Jingjun Han 

作者机构：Department of Mathematics University of Utah Beijing International Center for Mathematical Research Peking University 

出 版 物：《Science China Mathematics》 (中国科学：数学（英文版）)

年 卷 期：2019年第62卷第3期

页      面：411-416页

核心收录：

学科分类：07[理学] 070104[理学-应用数学] 0701[理学-数学] 

基　　金：supported by National Science Foundation of USA (Grant Nos. DMS-1300750 and DMS-1265285) by a grant from the Simons Foundation (Grant No. 256202) 

主　　题：minimal model program non-klt locus connectedness 

摘      要：Let(X, ?) be a log pair over S, such that-(KX+ ?) is nef over S. It is conjectured that the intersection of the non-klt(non Kawamata log terminal) locus of(X, ?) with any fiber Xs has at most two connected components. We prove this conjecture in dimension no greater than 4 and in arbitrary dimension assuming the termination of klt flips.