{"title":"巢代数的大扰动","authors":"Kenneth R. Davidson","doi":"arxiv-2408.03317","DOIUrl":null,"url":null,"abstract":"Let $\\mathcal{M}$ and $\\mathcal{N}$ be nests on separable Hilbert space. If\nthe two nest algebras are distance less than 1\n($d(\\mathcal{T}(\\mathcal{M}),\\mathcal{T}(\\mathcal{N})) < 1$), then the nests\nare distance less than 1 ($d(\\mathcal{M},\\mathcal{N})<1$). If the nests are\ndistance less than 1 apart, then the nest algebras are similar, i.e. there is\nan invertible $S$ such that $S\\mathcal{M} = \\mathcal{N}$, so that $S\n\\mathcal{T}(\\mathcal{M})S^{-1} = \\mathcal{T}(\\mathcal{N})$. However there are\nexamples of nests closer than 1 for which the nest algebras are distance 1\napart.","PeriodicalId":501114,"journal":{"name":"arXiv - MATH - Operator Algebras","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Large Perturbations of Nest Algebras\",\"authors\":\"Kenneth R. Davidson\",\"doi\":\"arxiv-2408.03317\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Let $\\\\mathcal{M}$ and $\\\\mathcal{N}$ be nests on separable Hilbert space. If\\nthe two nest algebras are distance less than 1\\n($d(\\\\mathcal{T}(\\\\mathcal{M}),\\\\mathcal{T}(\\\\mathcal{N})) < 1$), then the nests\\nare distance less than 1 ($d(\\\\mathcal{M},\\\\mathcal{N})<1$). If the nests are\\ndistance less than 1 apart, then the nest algebras are similar, i.e. there is\\nan invertible $S$ such that $S\\\\mathcal{M} = \\\\mathcal{N}$, so that $S\\n\\\\mathcal{T}(\\\\mathcal{M})S^{-1} = \\\\mathcal{T}(\\\\mathcal{N})$. However there are\\nexamples of nests closer than 1 for which the nest algebras are distance 1\\napart.\",\"PeriodicalId\":501114,\"journal\":{\"name\":\"arXiv - MATH - Operator Algebras\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2024-08-06\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"arXiv - MATH - Operator Algebras\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/arxiv-2408.03317\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"arXiv - MATH - Operator Algebras","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/arxiv-2408.03317","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
Let $\mathcal{M}$ and $\mathcal{N}$ be nests on separable Hilbert space. If
the two nest algebras are distance less than 1
($d(\mathcal{T}(\mathcal{M}),\mathcal{T}(\mathcal{N})) < 1$), then the nests
are distance less than 1 ($d(\mathcal{M},\mathcal{N})<1$). If the nests are
distance less than 1 apart, then the nest algebras are similar, i.e. there is
an invertible $S$ such that $S\mathcal{M} = \mathcal{N}$, so that $S
\mathcal{T}(\mathcal{M})S^{-1} = \mathcal{T}(\mathcal{N})$. However there are
examples of nests closer than 1 for which the nest algebras are distance 1
apart.