
Journal of Lie Theory 32 (2022), No. 3, 813819 Copyright Heldermann Verlag 2022 On Semisimple Standard Compact CliffordKlein Forms Maciej Bochenski Faculty of Mathematics and Computer Science, University of Warmia and Mazury, Olsztyn, Poland mabo@matman.uwm.edu.pl We give the classification of standard compact CliffordKlein forms corresponding to triples (g, h, l) such that g = h + l and g is a sum of two absolutely simple ideals. The classification is done using Onishchik's results concerning semisimple decompositions of semisimple Lie algebras. Using this classification we obtain new examples of reductive homogeneous spaces admitting nonstandard compact CliffordKlein forms. Keywords: Homogeneous spaces, proper actions, discrete subgroups, CliffordKlein forms. MSC: 57S30, 17B20, 22F30. [ Fulltextpdf (102 KB)] for subscribers only. 