Saved in:
Bibliographic Details
Main Author: Peterson, Carsten
Format: Preprint
Published: 2023
Subjects:
Online Access:https://arxiv.org/abs/2304.08641
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866909056352911360
author Peterson, Carsten
author_facet Peterson, Carsten
contents We study joint eigenfunctions of the spherical Hecke algebra acting on $L^2(Γ_n \backslash G / K)$ where $G = \text{PGL}(3, F)$ with $F$ a non-archimedean local field of arbitrary characteristic, $K = \text{PGL}(3, O)$ with $O$ the ring of integers of $F$, and $(Γ_n)$ is a sequence of torsion-free lattices. We prove a form of equidistribution on average for eigenfunctions whose spectral parameters lie in the tempered spectrum when the associated sequence of quotients of the Bruhat-Tits building Benjamini-Schramm converges to the building itself. This result is a higher rank non-archimedean analogue of existing results for graphs and locally symmetric spaces. A recurring theme in the proof is the reduction of many computations to computing the sum of an exponential function over lattice points in a polytope; such expressions can subsequently be simplified using Brion's formula. Along the way of proving our main result we prove several other results which may be of independent interest including a "degenerate" version of Brion's formula which "interpolates" between the usual Brion's formula and the Ehrhart polynomial, an effective rate of convergence for the distribution of spectral parameters to the Plancherel measure under Benjamini-Schramm convergence, and a classification of relative positions of triples of points in buildings of type $\tilde{A}_2$.
format Preprint
id arxiv_https___arxiv_org_abs_2304_08641
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Quantum ergodicity on the Bruhat-Tits building for $\text{PGL}(3, F)$ in the Benjamini-Schramm limit
Peterson, Carsten
Representation Theory
Combinatorics
Metric Geometry
Spectral Theory
58J51, 20E42, 11F85, 11F72, 51E24, 22E35, 22E50, 37A46, 52B20
We study joint eigenfunctions of the spherical Hecke algebra acting on $L^2(Γ_n \backslash G / K)$ where $G = \text{PGL}(3, F)$ with $F$ a non-archimedean local field of arbitrary characteristic, $K = \text{PGL}(3, O)$ with $O$ the ring of integers of $F$, and $(Γ_n)$ is a sequence of torsion-free lattices. We prove a form of equidistribution on average for eigenfunctions whose spectral parameters lie in the tempered spectrum when the associated sequence of quotients of the Bruhat-Tits building Benjamini-Schramm converges to the building itself. This result is a higher rank non-archimedean analogue of existing results for graphs and locally symmetric spaces. A recurring theme in the proof is the reduction of many computations to computing the sum of an exponential function over lattice points in a polytope; such expressions can subsequently be simplified using Brion's formula. Along the way of proving our main result we prove several other results which may be of independent interest including a "degenerate" version of Brion's formula which "interpolates" between the usual Brion's formula and the Ehrhart polynomial, an effective rate of convergence for the distribution of spectral parameters to the Plancherel measure under Benjamini-Schramm convergence, and a classification of relative positions of triples of points in buildings of type $\tilde{A}_2$.
title Quantum ergodicity on the Bruhat-Tits building for $\text{PGL}(3, F)$ in the Benjamini-Schramm limit
topic Representation Theory
Combinatorics
Metric Geometry
Spectral Theory
58J51, 20E42, 11F85, 11F72, 51E24, 22E35, 22E50, 37A46, 52B20
url https://arxiv.org/abs/2304.08641