Lie Groups and Representation Theory

Seminar information archive ~03/28Next seminarFuture seminars 03/29~

Date, time & place Tuesday 16:30 - 18:00 126Room #126 (Graduate School of Math. Sci. Bldg.)

2021/06/22

17:00-18:00   Room #Online (Graduate School of Math. Sci. Bldg.)
Yosuke MORITA (Kyoto University)
Cartan projections of some nonreductive subgroups and the existence problem of compact Clifford-Klein forms (Japanese)
[ Abstract ]
Let G be a reductive Lie group, H a closed subgroup of G, and Γ a discrete subgroup of G.
According to the Kobayashi-Benoist criterion, the properness of the Γ-action on G/H is determined by the Cartan projections of H and Γ.
Although the Cartan projections of nonreductive subgroups are usually difficult to compute, there are some exceptions. Using them, we give some examples of homogeneous spaces of reductive type that do not admit compact Clifford-Klein forms.