7 research outputs found
Infinite transitivity, finite generation, and Demazure roots
An affine algebraic variety X of dimension at least 2 is called flexible if
the subgroup SAut(X) in Aut(X) generated by the one-parameter unipotent
subgroups acts m-transitively on reg(X) for any m 1. In the previous
paper we proved that any nondegenerate toric affine variety X is flexible. In
the present paper we show that one can find a subgroup of SAut(X) generated by
a finite number of one-parameter unipotent subgroups which has the same
transitivity property, provided the toric variety X is smooth in codimension 2.
For X= with n2, three such subgroups suffice.Comment: 25 page
多項式環のある指数自己同型の余順性
kを標数0の体とする.k代数k[x]の自己同型ϕが余順であるとは,ϕとアフィン自己同型全体で生成されるk[x]の自己同型群の部分群が順部分群を含むときにいう。本論分では,ある指数自己同型の余順性を決定した。首都大学東京, 2018-09-30, 修士(理学)首都大学東