The behavior of essential dimension under specialization, II

被引：0
作者：
Reichstein, Zinovy [1 ]
Scavia, Federico [2 ]
机构：
[1] Univ British Columbia, Dept Math, Vancouver, BC, Canada
[2] Univ Calif Los Angeles, Dept Math, Los Angeles, CA USA
来源：
ALGEBRA & NUMBER THEORY | 2023年 / 17卷 / 11期
关键词：
essential dimension; algebraic group; group action; torsor; complete intersection; TORSORS; INDEX;
D O I：
10.2140/ant.2023.17.1925
中图分类号：
O1 [数学];
学科分类号：
0701 ; 070101 ;
摘要：
Let G be a linear algebraic group over a field. We show that, under mild assumptions, in a family of primitive generically free G -varieties over a base variety B, the essential dimension of the geometric fibers may drop on a countable union of Zariski closed subsets of B and stays constant away from this countable union. We give several applications of this result.
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收藏
页码：1925 / 1958
页数：37
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