{"title":"操作性 2-局部自动形态/派生","authors":"Liguang Wang, Ngai-Ching Wong","doi":"arxiv-2407.10150","DOIUrl":null,"url":null,"abstract":"Let $\\phi: A\\to A$ be a (not necessarily linear, additive or continuous) map of a standard operator algebra. Suppose for any $a,b\\in A$ there is an\nalgebra automorphism $\\theta_{a,b}$ of $ A$ such that \\begin{align*}\n\\phi(a)\\phi(b) = \\theta_{a,b}(ab). \\end{align*} We show that either $\\phi$ or\n$-\\phi$ is a linear Jordan homomorphism. Similar results are obtained when any of the following conditions is\nsatisfied: \\begin{align*} \\phi(a) + \\phi(b) &= \\theta_{a,b}(a+b), \\\\\n\\phi(a)\\phi(b)+\\phi(b)\\phi(a) &= \\theta_{a,b}(ab+ba), \\quad\\text{or} \\\\\n\\phi(a)\\phi(b)\\phi(a) &= \\theta_{a,b}(aba). \\end{align*} We also show that a map $\\phi: M\\to M$ of a semi-finite von Neumann algebra $\nM$ is a linear derivation if for every $a,b\\in M$ there is a linear derivation\n$D_{a,b}$ of $M$ such that $$ \\phi(a)b + a\\phi(b) = D_{a,b}(ab). $$","PeriodicalId":501114,"journal":{"name":"arXiv - MATH - Operator Algebras","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2024-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Operational 2-local automorphisms/derivations\",\"authors\":\"Liguang Wang, Ngai-Ching Wong\",\"doi\":\"arxiv-2407.10150\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Let $\\\\phi: A\\\\to A$ be a (not necessarily linear, additive or continuous) map of a standard operator algebra. Suppose for any $a,b\\\\in A$ there is an\\nalgebra automorphism $\\\\theta_{a,b}$ of $ A$ such that \\\\begin{align*}\\n\\\\phi(a)\\\\phi(b) = \\\\theta_{a,b}(ab). \\\\end{align*} We show that either $\\\\phi$ or\\n$-\\\\phi$ is a linear Jordan homomorphism. Similar results are obtained when any of the following conditions is\\nsatisfied: \\\\begin{align*} \\\\phi(a) + \\\\phi(b) &= \\\\theta_{a,b}(a+b), \\\\\\\\\\n\\\\phi(a)\\\\phi(b)+\\\\phi(b)\\\\phi(a) &= \\\\theta_{a,b}(ab+ba), \\\\quad\\\\text{or} \\\\\\\\\\n\\\\phi(a)\\\\phi(b)\\\\phi(a) &= \\\\theta_{a,b}(aba). \\\\end{align*} We also show that a map $\\\\phi: M\\\\to M$ of a semi-finite von Neumann algebra $\\nM$ is a linear derivation if for every $a,b\\\\in M$ there is a linear derivation\\n$D_{a,b}$ of $M$ such that $$ \\\\phi(a)b + a\\\\phi(b) = D_{a,b}(ab). $$\",\"PeriodicalId\":501114,\"journal\":{\"name\":\"arXiv - MATH - Operator Algebras\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2024-07-14\",\"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-2407.10150\",\"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-2407.10150","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
Let $\phi: A\to A$ be a (not necessarily linear, additive or continuous) map of a standard operator algebra. Suppose for any $a,b\in A$ there is an
algebra automorphism $\theta_{a,b}$ of $ A$ such that \begin{align*}
\phi(a)\phi(b) = \theta_{a,b}(ab). \end{align*} We show that either $\phi$ or
$-\phi$ is a linear Jordan homomorphism. Similar results are obtained when any of the following conditions is
satisfied: \begin{align*} \phi(a) + \phi(b) &= \theta_{a,b}(a+b), \\
\phi(a)\phi(b)+\phi(b)\phi(a) &= \theta_{a,b}(ab+ba), \quad\text{or} \\
\phi(a)\phi(b)\phi(a) &= \theta_{a,b}(aba). \end{align*} We also show that a map $\phi: M\to M$ of a semi-finite von Neumann algebra $
M$ is a linear derivation if for every $a,b\in M$ there is a linear derivation
$D_{a,b}$ of $M$ such that $$ \phi(a)b + a\phi(b) = D_{a,b}(ab). $$