A note on the Tits systems of Kac-Moody Steinberg groups
Let \(G\) and \(H\) denote the Chevalley (adjoint) and the Steinberg (nonadjoint) Kac-Moody group corresponding to a Kac-Moody algebra \(L\), respectively. Let \(\sigma\) denote the canonical homomorphism of \(H\) onto \(G\) which by an earlier result of the author is a canonical group map of the Weyl simple subgroup of \(H\) onto \(G\). In this note the author proves that the \(\sigma\)-inverse image of a Tits system in \(G\) forms a Tits system in the Weyl simple subgroup of \(H\).
scientific article; zbMATH DE number 1102797