{ "id": "1710.04351", "version": "v1", "published": "2017-10-12T03:22:20.000Z", "updated": "2017-10-12T03:22:20.000Z", "title": "Extended Okounkov bodies and multi-point Seshadri constants", "authors": [ "Jaesun Shin" ], "comment": "33 pages, comments are welcome", "categories": [ "math.AG" ], "abstract": "Based on the work of Okounkov, Lazarsfeld-Mustata and Kaveh-Khovanskii independently associated a convex body, called the Okounkov body, to a big divisor on a smooth projective variety with respect to an admissible flag. Although the Okounkov bodies carry rich positivity data of big divisors, they only provide information near a single point. The purpose of this paper is to introduce a convex body of a big divisor that is effective in handling the positivity theory associated with multi-point settings. These convex bodies open the door to approach the local positivity theory at multiple points from a convex-geometric perspective. We study their various properties and their shapes, and observe local positivity data via them. Finally, we give some applications, especially for the Nagata conjecture.", "revisions": [ { "version": "v1", "updated": "2017-10-12T03:22:20.000Z" } ], "analyses": { "subjects": [ "14C20", "14J99" ], "keywords": [ "multi-point seshadri constants", "okounkov body", "extended okounkov bodies", "convex body", "big divisor" ], "note": { "typesetting": "TeX", "pages": 33, "language": "en", "license": "arXiv", "status": "editable" } } }