Karlheinz Gröchenig, José Luis Romero, Michael Speckbacher
{"title":"Hölder-Continuity of Extreme Spectral Values of Pseudodifferential Operators, Gabor Frame Bounds, and Saturation","authors":"Karlheinz Gröchenig, José Luis Romero, Michael Speckbacher","doi":"arxiv-2407.18065","DOIUrl":null,"url":null,"abstract":"We build on our recent results on the Lipschitz dependence of the extreme\nspectral values of one-parameter families of pseudodifferential operators with\nsymbols in a weighted Sj\\\"ostrand class. We prove that larger symbol classes\nlead to H\\\"older continuity with respect to the parameter. This result is then\nused to investigate the behavior of frame bounds of families of Gabor systems\n$\\mathcal{G}(g,\\alpha\\Lambda)$ with respect to the parameter $\\alpha>0$, where\n$\\Lambda$ is a set of non-uniform, relatively separated time-frequency shifts,\nand $g\\in M^1_s(\\mathbb{R}^d)$, $0\\leq s\\leq 2$. In particular, we show that\nthe frame bounds depend continuously on $\\alpha$ if $g\\in M^1(\\mathbb{R}^d)$,\nand are H\\\"older continuous if $g\\in M^1_s(\\mathbb{R}^d)$, $0<s\\leq 2$, with\nthe H\\\"older exponent explicitly given.","PeriodicalId":501373,"journal":{"name":"arXiv - MATH - Spectral Theory","volume":"15 1","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"arXiv - MATH - Spectral Theory","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/arxiv-2407.18065","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
Abstract
We build on our recent results on the Lipschitz dependence of the extreme
spectral values of one-parameter families of pseudodifferential operators with
symbols in a weighted Sj\"ostrand class. We prove that larger symbol classes
lead to H\"older continuity with respect to the parameter. This result is then
used to investigate the behavior of frame bounds of families of Gabor systems
$\mathcal{G}(g,\alpha\Lambda)$ with respect to the parameter $\alpha>0$, where
$\Lambda$ is a set of non-uniform, relatively separated time-frequency shifts,
and $g\in M^1_s(\mathbb{R}^d)$, $0\leq s\leq 2$. In particular, we show that
the frame bounds depend continuously on $\alpha$ if $g\in M^1(\mathbb{R}^d)$,
and are H\"older continuous if $g\in M^1_s(\mathbb{R}^d)$, $0