Download this article
 Download this article For screen
For printing
Recent Issues
Volume 3, Issue 1
Volume 2, Issue 1
Volume 1, Issue 1
The Journal
About the journal
Ethics and policies
Peer-review process
 
Submission guidelines
Submission form
Editorial board
 
ISSN 2834-4634 (online)
ISSN 2834-4626 (print)
Author index
To appear
 
Other MSP Journals
Subconvexity implies effective quantum unique ergodicity for Hecke–Maa{\ss} cusp forms on $\operatorname{SL}_2(\mathbb{Z}) \backslash \operatorname{SL}_2(\mathbb{R})$

Ankit Bisain, Peter Humphries, Andrei Mandelshtam, Noah Walsh and Xun Wang

Vol. 3 (2024), No. 1, 101–144
Abstract

It is a folklore result in arithmetic quantum chaos that quantum unique ergodicity on the modular surface with an effective rate of convergence follows from subconvex bounds for certain triple product L-functions. The physical space manifestation of this result, namely the equidistribution of mass of Hecke–Maaß cusp forms, was proven to follow from subconvexity by Watson, whereas the phase space manifestation of quantum unique ergodicity has only previously appeared in the literature for Eisenstein series via work of Jakobson. We detail the analogous phase space result for Hecke–Maaß cusp forms. The proof relies on the Watson–Ichino triple product formula together with a careful analysis of certain archimedean integrals of Whittaker functions.

Keywords
quantum chaos, quantum unique ergodicity, subconvexity
Mathematical Subject Classification
Primary: 11F12
Secondary: 11F66, 11F67, 58J51, 81Q50
Milestones
Received: 23 February 2024
Revised: 5 September 2024
Accepted: 6 September 2024
Published: 26 September 2024
Authors
Ankit Bisain
Department of Mathematics
Massachusetts Institute of Technology
Cambridge, MA
United States
Peter Humphries
Department of Mathematics
University of Virginia
Charlottesville, VA
United States
Andrei Mandelshtam
Department of Mathematics
Stanford University
Stanford, CA
United States
Noah Walsh
Department of Mathematics
Massachusetts Institute of Technology
Cambridge, MA
United States
Xun Wang
Department of Mathematics
Northwestern University
Evanston, IL
United States