PreprintarXiv licencearXiv
Improved sup-norm bounds for locally symmetric spaces
Abstract
Let X=G/K be a symmetric space of noncompact type, of dimension n and rank r, and let Y=Γbackslash X. Sarnak's local bound for an L2-normalized spherical joint eigenfunction with regular tempered parameter of size T is |ϕ|∞≪ T(n−r)/2. We prove o(T(n−r)/2) locally uniformly on every quotient. On finite-volume real hyperbolic manifolds this is uniform in the expanding cusp range y≤ Tβ, β<1/2. If the injectivity radius is bounded below, we prove the global estimate T(n−r)/2(log T)−r/2. The proof makes use of a novel kernel argument and a uniform bound on the spherical function.
Related
- Locally symmetric hypersurfaces in globally symmetric spaces
- Relevant sampling of non-decaying signals in Orlicz and mixed-norm Orlicz spaces defined on a locally compact group
- Perverse Euler Characteristics of Hermitian Locally Symmetric Spaces
- Bounded orbits on homogeneous spaces and bounded geodesics on locally symmetric spaces
- Minimal Submanifolds and Waists of Locally Symmetric Spaces
BibTeX
@misc{lutsko2026improved,
title = {{Improved sup-norm bounds for locally symmetric spaces}},
author = {Christopher Lutsko},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2608.21580},
eprint = {2608.21580},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2608.21580},
}
RIS
TY - UNPB
TI - Improved sup-norm bounds for locally symmetric spaces
AU - Christopher Lutsko
PY - 2026
DA - 2026/09/15
PB - arXiv
DO - 10.48550/arxiv.2608.21580
UR - https://arxiv.org/abs/2608.21580
AB - Let X=G/K be a symmetric space of noncompact type, of dimension n and rank r, and let Y=Γbackslash X. Sarnak's local bound for an L^2-normalized spherical joint eigenfunction with regular tempered parameter of size T is |ϕ|_∞≪ T^(n−r)/2. We prove o(T^(n−r)/2) locally uniformly on every quotient. On finite-volume real hyperbolic manifolds this is uniform in the expanding cusp range y≤ T^β, β<1/2. If the injectivity radius is bounded below, we prove the global estimate T^(n−r)/2(log T)^−r/2. The proof makes use of a novel kernel argument and a uniform bound on the spherical function.
ER -