2018/11/15 by Damian Sercombe, Sercombe, Damian
Mathematics · #20G20 #FOS: Mathematics #Group Theory (math.GR) #math.GR #msc:20G20
paper · pdf · doi:10.48550/arxiv.1811.06327
arxiv created 2018/11/15 · arxiv updated 2018/11/16
Let G be a connected real algebraic group. An unrefinable chain of G is a chain of subgroups G=G0>G1>...>Gt=1 where each Gi is a maximal connected real subgroup of Gi-1. The maximal (respectively, minimal) length of such an unrefinable chain is called the length (respectively, depth) of G. We give a precise formula for the length of G, which generalises results of Burness, Liebeck and Shalev on complex algebraic groups and also on compact Lie groups. If G is simple then we bound the depth of G above and below, and in many cases we compute the exact value. In particular, the depth of any simple G is at most 9.