Volumes of S-arithmetic quotients of semi-simple groups. With an appendix by Moshe Jarden and Gopal Prasad. (English) Zbl 0695.22005

Let k be a global field and G a semi-simple algebraic group defined over k. Let S be a finite set of places of k containing the archimedean ones. For G simply connected and absolutely quasi-simple a formula is given for the volume of \(G(k_ S)/\Lambda\), where \(\Lambda\) is an S-arithmetic subgroup of G(k). The derivation of this formula is possible thanks to the theory of reductive groups over local fields of Bruhat and Tits. The same computations give a bound for class numbers.
Reviewer: J.G.M.Mars


22E46 Semisimple Lie groups and their representations
20G30 Linear algebraic groups over global fields and their integers
22E40 Discrete subgroups of Lie groups
11R23 Iwasawa theory
Full Text: DOI Numdam EuDML