The necessity of conditions for graph quantum ergodicity and Cartesian products with an infinite graph

Anantharaman and Le Masson proved that any family of eigenbases of the adjacency operators of a family of graphs is quantum ergodic (a form of delocalization) assuming the graphs satisfy conditions of expansion and high girth. In this paper, we show that neither of these two conditions is sufficient...

Full description

Bibliographic Details
Main Author: McKenzie, Theo
Format: Article
Language:English
Published: Académie des sciences 2022-04-01
Series:Comptes Rendus. Mathématique
Online Access:https://comptes-rendus.academie-sciences.fr/mathematique/articles/10.5802/crmath.316/
_version_ 1797651472849043456
author McKenzie, Theo
author_facet McKenzie, Theo
author_sort McKenzie, Theo
collection DOAJ
description Anantharaman and Le Masson proved that any family of eigenbases of the adjacency operators of a family of graphs is quantum ergodic (a form of delocalization) assuming the graphs satisfy conditions of expansion and high girth. In this paper, we show that neither of these two conditions is sufficient by itself to necessitate quantum ergodicity. We also show that having conditions of expansion and a specific relaxation of the high girth constraint present in later papers on quantum ergodicity is not sufficient. We do so by proving new properties of the Cartesian product of two graphs where one is infinite.
first_indexed 2024-03-11T16:16:18Z
format Article
id doaj.art-6a92276ae8e4446ca32109989b31b678
institution Directory Open Access Journal
issn 1778-3569
language English
last_indexed 2024-03-11T16:16:18Z
publishDate 2022-04-01
publisher Académie des sciences
record_format Article
series Comptes Rendus. Mathématique
spelling doaj.art-6a92276ae8e4446ca32109989b31b6782023-10-24T14:19:45ZengAcadémie des sciencesComptes Rendus. Mathématique1778-35692022-04-01360G439940810.5802/crmath.31610.5802/crmath.316The necessity of conditions for graph quantum ergodicity and Cartesian products with an infinite graphMcKenzie, Theo0Evans Hall, University of California, Berkeley, CA, USAAnantharaman and Le Masson proved that any family of eigenbases of the adjacency operators of a family of graphs is quantum ergodic (a form of delocalization) assuming the graphs satisfy conditions of expansion and high girth. In this paper, we show that neither of these two conditions is sufficient by itself to necessitate quantum ergodicity. We also show that having conditions of expansion and a specific relaxation of the high girth constraint present in later papers on quantum ergodicity is not sufficient. We do so by proving new properties of the Cartesian product of two graphs where one is infinite.https://comptes-rendus.academie-sciences.fr/mathematique/articles/10.5802/crmath.316/
spellingShingle McKenzie, Theo
The necessity of conditions for graph quantum ergodicity and Cartesian products with an infinite graph
Comptes Rendus. Mathématique
title The necessity of conditions for graph quantum ergodicity and Cartesian products with an infinite graph
title_full The necessity of conditions for graph quantum ergodicity and Cartesian products with an infinite graph
title_fullStr The necessity of conditions for graph quantum ergodicity and Cartesian products with an infinite graph
title_full_unstemmed The necessity of conditions for graph quantum ergodicity and Cartesian products with an infinite graph
title_short The necessity of conditions for graph quantum ergodicity and Cartesian products with an infinite graph
title_sort necessity of conditions for graph quantum ergodicity and cartesian products with an infinite graph
url https://comptes-rendus.academie-sciences.fr/mathematique/articles/10.5802/crmath.316/
work_keys_str_mv AT mckenzietheo thenecessityofconditionsforgraphquantumergodicityandcartesianproductswithaninfinitegraph
AT mckenzietheo necessityofconditionsforgraphquantumergodicityandcartesianproductswithaninfinitegraph