Representation growth of linear groups
Journal of the European Mathematical Society, Tome 10 (2008) no. 2, pp. 351-390
Cet article a éte moissonné depuis la source EMS Press
Let Γ be a group and rn(Γ) the number of its n-dimensional irreducible complex representations. We define and study the associated representation zeta function ZΓ(s)=∑n=1∞rn(Γ)n−s. When Γ is an arithmetic group satisfying the congruence subgroup property then ZΓ(s) has an “Euler factorization”. The “factor at infinity” is sometimes called the “Witten zeta function” counting the rational representations of an algebraic group. For these we determine precisely the abscissa of convergence. The local factor at a finite place counts the finite representations of suitable open subgroups U of the associated simple group G over the associated local field K. Here we show a surprising dichotomy: if G(K) is compact (i.e. G anisotropic over K) the abscissa of convergence goes to 0 when dimG goes to infinity, but for isotropic groups it is bounded away from 0. As a consequence, there is an unconditional positive lower bound for the abscissa for arbitrary finitely generated linear groups. We end with some observations and conjectures regarding the global abscissa.
Classification :
11-XX, 20-XX, 22-XX, 00-XX
Keywords: Representation growth, p-adic group, arithmetic group
Keywords: Representation growth, p-adic group, arithmetic group
@article{JEMS_2008_10_2_a2,
author = {Michael Larsen and Alexander Lubotzky},
title = {Representation growth of linear groups},
journal = {Journal of the European Mathematical Society},
pages = {351--390},
year = {2008},
volume = {10},
number = {2},
doi = {10.4171/jems/113},
url = {http://geodesic.mathdoc.fr/articles/10.4171/jems/113/}
}
Michael Larsen; Alexander Lubotzky. Representation growth of linear groups. Journal of the European Mathematical Society, Tome 10 (2008) no. 2, pp. 351-390. doi: 10.4171/jems/113
Cité par Sources :