Abstract
The classical Waring problem deals with expressing every natural number as a sum of g(k) k th powers. Similar problems were recently studied in group theory, where we aim to present group elements as short products of values of a given word w ≠ 1. In this paper we study this problem for Lie groups and Chevalley groups over infinite fields.
We show that for a fixed word w ≠ 1 and for a classical connected real compact Lie group G of sufficiently large rank we have w(G)2 = G, namely every element of G is a product of 2 values of w.
We prove a similar result for non-compact Lie groups of arbitrary rank, arising from Chevalley groups over ℝ or over a p-adic field. We also study this problem for Chevalley groups over arbitrary infinite fields, and show in particular that every element in such a group is a product of two squares.
Similar content being viewed by others
References
N. Avni, T. Gelander, M. Kassabov and A. Shalev, Word values in p-adic and adelic groups, Bulletin London Mathematical Society 45 (2013), 1323–1330.
A. Borel, On free subgroups of semisimple groups, L’Enseignement Mathématique 29 (1983), 151–164.
E. W. Ellers and N. L. Gordeev, Gauss decomposition with prescribed semisimple part in classical Chevalley groups, Communications in Algebra 22 (1994), 5935–5950.
E. W. Ellers and N. L. Gordeev, Gauss decomposition with prescribed semisimple part in classical Chevalley groups II: Exceptional cases, Communications in Algebra 23 (1995), 3085–3098.
E. W. Ellers and N. L. Gordeev, Gauss decomposition with prescribed semisimple part in classical Chevalley groups III: Finite twisted groups, Communications in Algebra 24 (1996), 4447–4475.
A. Elkasapy and A. Thom, About Got?o’s method showing surjectivity of word maps, Indiana University Mathematics Journal 63 (2014), 1553–1565.
W. Fulton and J. Harris, Representation Theory, Graduate Texts in Mathematics 129 (1st ed.), Springer-Verlag, Berlin, 1991.
M. Gotô, A theorem on compact semi-simple groups, Journal of the Mathematical Society of Japan 1 (1949), 270–272.
M. Larsen, Word maps have large image, Israel Journal of Mathematics 139 (2004), 149–156.
M. Larsen and A. Shalev, Word maps and Waring type problems, Journal of the American Mathematical Society 22 (2009), 437–466.
M. Larsen and A. Shalev, Characters of symmetric groups: sharp bounds and applications, Inventiones mathematicae 174 (2008), 645–687.
M. Larsen and A. Shalev, On the distribution of values of certain word maps, Transactions of the American Mathematical Society, to appear. arXiv:1308.1286.
A. Lev, Products of cyclic conjugacy classes in the groups PSL(n, F), Linear Algebra and its Applications 179 (1993), 59–83.
M. Larsen, A. Shalev and P. Tiep, The Waring problem for finite simple groups, Annals of Mathematics 174 (2011), 1885–1950.
M. Larsen, A. Shalev and Ph. Tiep, Waring problem for finite quasisimple groups, International Mathematics Research Notices rns109 (2012), 26 pages.
M. W. Liebeck, E. A. O’Brien, A. Shalev and P. H. Tiep, The Ore Conjecture, Journal of the European Mathematical Society 12 (2010), 939–1008.
D. Segal, Words: Notes on Verbal Width in Groups, London Mathematical Society Lecture Note Series 361, Cambridge University Press, Cambridge, 2009.
J.-P. Serre, Exemples de plongements des groupes PSL2(F p) dans des groupes de Lie simples, Inventiones mathematicae 124 (1996), 525–562.
A. Shalev, Word maps, conjugacy classes, and a non-commutative Waring-type theorem, Annals of Mathematics 170 (2009), 1383–1416.
A. Shalev, Some problems and results in the theory of word maps, in Erdős Centennial, Lovász et al., eds. Bolyai Soc. Math. Studies 25 2013, pp. 611–649.
R. Steinberg, Lectures on Chevalley Groups, Yale University, 1967.
A. Thom Convergent sequences in discrete groups, The Canadian Mathematical Bulletin 56 (2013), 424–433.
R. C. Thompson Commutators in the special and general linear groups, Transactions of the American Mathematical Society 101 (1961), 16–33.
L. N. Vaserstein and E. Wheland, Products of conjugacy classes of two by two matrices, Linear Algebra and its Applications 230 (1995), 165–188.
Author information
Authors and Affiliations
Corresponding author
Additional information
The first author was supported by ERC Advanced Grant no. 247034.
The second author was partially supported by the Simons Foundation, the MSRI, NSF Grant DMS-1101424, and BSF Grant no. 2008194.
The third author was partially supported by ERC Advanced Grant no. 247034, ISF grant no. 1117/13, BSF Grant no. 2008194 and the Vinik Chair of Mathematics which he holds
Rights and permissions
About this article
Cite this article
Hui, C.Y., Larsen, M. & Shalev, A. The Waring problem for Lie groups and Chevalley groups. Isr. J. Math. 210, 81–100 (2015). https://doi.org/10.1007/s11856-015-1246-9
Received:
Revised:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11856-015-1246-9