Abstract
Let G be a simple Lie group with finite center. We show that G can be algebraically generated as a semigroup by a one-parameter subsemigroup X + and one additional element g. In fact, given one of the two, a non-constant X + or a non-central g, there is a g, respectively X +, such that the two together generate G as a semigroup. It follows that given a non-constant one-parameter subsemigroup X + of G there is another one-parameter subsemigroup Y + such that the two generate G as a semigroup. Similarly, given a non-central element g of G there is an element h of G such that the two generate a dense subsemigroup of G. We have analogous results for semismple Lie groups. For SL(2, ℝ) and its universal cover we spell out when two one-parameter subsemigroups generate the group as a semigroup. On the way we prove results on open subsets of subsemigroups and on exponentiality, which may be of independent interest.
Similar content being viewed by others
References
H. Abels, E. B. Vinberg, Generating semisimple groups by tori, J. Algebra 328 (2011), 114–121.
R. El Assoudi, J. P. Gauthier, I. A. K. Kupka, On subsemigroups of semisimple Lie groups, Annales de l’I.H.P., Sect. C 13 (1996), 117–133.
R. C. Gunning, H. Rossi, Analytic Functions of Several Complex Variables, Prentice-Hall, Englewood Cliffs, N.J., 1965. Russian transl.: Р. Ганниг, Х. Росси, Аналиmические функции многих комплексных переменных, Мир, M, 1969.
J. Hilgert, K. H. Hofmann, Old and new on SL(2), Manuscripta Math. 54 (1986), 17–52.
K. H. Hofmann, J. D. Lawson, Foundations of Lie semigroups, in: Recent Developments in the Algebraic, Analytical, and Topological Theory of Semigroups (Oberwolfach, 1981), Lecture Notes in Mathematics, Vol. 998, Springer, Berlin, 1983, pp. 128–201.
K. H. Hofmann, W. A. F. Ruppert, On the interior of subsemigroups of Lie groups, Trans. Amer. Math. Soc. 324 (1991), 169–179.
S. Kobayashi, K. Nomizu, Foundations of Differential Geometry, Vol. I, Interscience Tracts in Pure and Applied Mathematics, No. 15, Vol. I, Interscience Publishers, Wiley, New York, 1963. Russian transl.: Ш. Кобаяси, К. Номидзу, Основы дифференциальной геомеmрии, т. 1, Наука, M., 1981.
K.-H. Neeb, Semigroups in the universal covering group of SL(2), Semigroup Forum 43 (1991) 33–43.
L. San Martin, Invariant control sets on flag manifolds, Math. Control Signals Systems 6 (1993), 41–61.
M. Wüstner, Supplements on the theory of exponential Lie groups, J. Algebra 265 (2003)148-170.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
ABELS, H. SUBSEMIGROUPS OF SEMISIMPLE LIE GROUPS. Transformation Groups 20, 307–318 (2015). https://doi.org/10.1007/s00031-015-9303-3
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00031-015-9303-3