Abstract
The Gordon-Rodriguez-Villegas theorem says that, in a finite group, the number of solutions to a system of coefficient-free equations is divisible by the order of the group if the rank of the matrix composed of the exponent sums of the j-th unknown in the i-th equation is less than the number of unknowns. We obtain analogues of this and similar facts for algebraic groups. In particular, our results imply that the dimension of each irreducible component of the variety of homomorphisms from a finitely generated group with infinite abelianization into an algebraic group G is at least dimG.
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References
A. Amit and U. Vishne, Characters and solutions to equations in finite groups, Journal of Algebra and its Applications 10 (2011), 675–686.
A. Borel, Linear Algebraic Groups. W. A. Benjamin, New York-Amsterdam, 1969.
E. Breuillard, B. Green, R. Guralnick and T. Tao, Strongly dense free subgroups of semisimple algebraic groups, Israel Journal of Mathematics 192 (2012), 347–379.
E. K. Brusyanskaya, A. A. Klyachko and A. V. Vasil'ev, What do Frobenius's, Solomon's, and Iwasaki's theorems on divisibility in groups have in common?, Pacific Journal of Mathematics 302 (2019), 437–452.
N. L. Gordeev, B. E. Kunyavskiĭ and E. B. Plotkin, Geometry of word equations in simple algebraic groups over special fields, Russian Mathematical Surveys 73 (2018), 753–796.
C. Gordon and F. Rodriguez-Villegas, On the divisibility of #Hom(ΓG) |G|, Journal of Algebra 350 (2012), 300–307.
I. M. Isaacs, Systems of equations and generalized characters in groups, Canadian Journal of Mathematics 22 (1970), 1040–1046.
K. Kishore, Representation variety of surface groups, Proceedings of the American Mathematical Society 146 (2018), 953–959.
A. A. Klyachko and A. A. Mkrtchyan, How many tuples of group elements have a given property? With an appendix by Dmitrii V. Trushin, International Journal of Algebra and Computation 24 (2014), 413–428.
A. A. Klyachko and A. M. krtchyan, Strange divisibility in groups and rings, Archiv der Mathematik 108 (2017), 441–451.
M. Larsen and A. Lubotzky, Representation varieties of Fuchsian groups, in From Fourier Analysis and Number Theory to Radon Transforms and Geometry, Developments in Mathematics, Vol. 28, Springer, New York, 2013, pp. 375–397.
M. Liebeck and A. Shalev, Fuchsian groups, finite simple groups and representation varieties, Inventiones mathematicae 159 (2005), 317–367.
S. Liriano and S. Majewicz, Algebro-geometric invariants of groups (the dimension sequence of representation variety), International Journal of Algebra and Computation 21 (2011), 595–614.
D. D. Long and M. B. Thistlethwaite, The dimension of the Hitchin component for triangle groups, Geometriae Dedicata 200 (2019), 363–370.
J. Martín-Morales and A. M. Oller-Marcén, On the number of irreducible components of the representation variety of a family of one-relator groups, International Journal of Algebra and Computation 20 (2010), 77–87.
A. L. Onishchik and E. B. Vinberg, Lie Groups and Algebraic Groups, Springer Series in Soviet Mathematics, Springer, Berlin-Heidelberg, 1990.
A. S. Rapinchuk, V. V. Benyash-Krivetz and V. I. Chernousov, Representation varieties of the fundamental groups of compact orientable surfaces, Israel Journal of Mathematics 93 (1996), 29–71.
L. Solomon, The solutions of equations in groups, Archiv der Mathematik 20 (1969), 241–247.
S. P. Strunkov, On the theory of equations in finite groups, Izvestiya: Mathematics 59 (1995), 1273–1282.
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The work of the first author was supported by the Russian Foundation for Basic Research, project no. 19-01-00591.
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Klyachko, A.A., Ryabtseva, M.A. The dimension of solution sets to systems of equations in algebraic groups. Isr. J. Math. 237, 141–154 (2020). https://doi.org/10.1007/s11856-020-2002-3
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DOI: https://doi.org/10.1007/s11856-020-2002-3