Existence of log canonical modifications and its applications
arXiv:2103.01417
Abstract
The main purpose of this paper is to establish some useful partial resolutions of singularities for pairs from the minimal model theoretic viewpoint. We first establish the existence of log canonical modifications of normal pairs under some suitable assumptions. It recovers Kawakita's inversion of adjunction on log canonicity in full generality. We also discuss the existence of semi-log canonical modifications for demi-normal pairs and construct dlt blow-ups with several extra good properties. As applications, we study lengths of extremal rational curves and so on.
25 pages. version 2. Example 1.2 was added, other minor changes. arXiv admin note: text overlap with arXiv:2102.11986