On the Seshadri constants of adjoint line bundles

被引:3
|
作者
Bauer, Thomas [1 ]
Szemberg, Tomasz [2 ]
机构
[1] Univ Marburg, Fachbereich Math & Informat, D-35032 Marburg, Germany
[2] Inst Matematyki UP, PL-30084 Krakow, Poland
关键词
SURFACES; CURVES;
D O I
10.1007/s00229-010-0418-5
中图分类号
O1 [数学];
学科分类号
0701 ; 070101 ;
摘要
In the present paper we study the possible values of Seshadri constants. While in general every positive rational number appears as the local Seshadri constant of some ample line bundle, we point out that for adjoint line bundles there are explicit lower bounds depending only on the dimension of the underlying variety. In the surface case, where the optimal lower bound is 1/2, we characterize all possible values in the range between 1/2 and 1-there are surprisingly few. As expected, one obtains even more restrictive results for the Seshadri constants of adjoints of very ample line bundles. Finally, we study Seshadri constants of adjoint line bundles in the multi-point setting.
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页码:215 / 228
页数:14
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