LIMIT MULTIPLICITIES FOR PRINCIPAL CONGRUENCE SUBGROUPS OF GL(n) AND SL(n)

作者：Finis Tobias^*; Lapid Erez; Mueller Werner

来源：Journal of the Institute of Mathematics of Jussieu, 2015, 14(3): 589-638.

DOI：10.1017/S1474748014000103

• limit multiplicities
• lattices in Lie groups
• trace formula

We study the limiting behavior of the discrete spectra associated to the principal congruence subgroups of a reductive group over a number field. While this problem is well understood in the cocompact case (i.e., when the group is anisotropic modulo the center), we treat groups of unbounded rank. For the groups GL(n) and SL(n) we show that the suitably normalized spectra converge to the Plancherel measure (the limit multiplicity property). For general reductive groups we obtain a substantial reduction of the problem. Our main tool is the recent refinement of the spectral side of Arthur's trace formula obtained in [Finis, Lapid, and Muller, Ann. of Math. (2) 174(1) (2011), 173-195; Finis and Lapid, Ann. of Math. (2) 174(1) (2011), 197-223], which allows us to show that for GL(n) and SL(n) the contribution of the continuous spectrum is negligible in the limit.

• 出版日期2015-7