Twisted root system of a (*)-subgroup. (arXiv:1805.06330v1 [math.GR])

We classify (*)-subgroups of compact Lie groups of adjoint type, and associate a twisted root system to every (*)-subgroup. We study the structure of twisted root system in several aspects: properties of the small Weyl group W_{small} and its normal subgroups W_{tiny} and W_{f}; properties of finite root datum; structure of strips of infinite roots. 查看全文>>