M. Asadi, Zahra Hassanpour Yakhdani, Fatemeh Olyaninezhad, A. Sahleh
{"title":"Hilbert \\(C_{0}(Z)\\) -模上的近似正交保持映射","authors":"M. Asadi, Zahra Hassanpour Yakhdani, Fatemeh Olyaninezhad, A. Sahleh","doi":"10.3336/gm.57.1.05","DOIUrl":null,"url":null,"abstract":"In this paper, we will use the categorical approach to\nHilbert \\(C^{\\ast}\\)-modules over a commutative \\(C^{\\ast}\\)-algebra\nto investigate the approximately orthogonality preserving mappings\non Hilbert \\(C^{\\ast}\\)-modules over a commutative\n\\(C^{\\ast}\\)-algebra.\n\n Indeed, we show that if \\(\\Psi:\\Gamma \\rightarrow \\Gamma^{\\prime}\n\\) is a nonzero \\( C_{0}(Z) \\)-linear\n \\(( \\delta , \\varepsilon)\\)-orthogonality preserving mapping\n between the continuous fields of Hilbert spaces on a locally\ncompact Hausdorff space \\(Z\\), then \\(\\Psi\\) is injective, continuous\nand also for every \\( x, y \\in \\Gamma \\) and \\(z \\in Z\\),\n\\[\n\n\n\n\\vert\n\\langle \\Psi(x),\\Psi(y) \\rangle(z) - \\varphi^2(z) \\langle x,y\n\\rangle(z) \\vert \\leq \\frac{4(\\varepsilon -\n\\delta)}{(1-\\delta)(1+\\varepsilon)} \\Vert \\Psi(x) \\Vert \\Vert\n\\Psi(y) \\Vert,\n\n\n\\]\nwhere \\(\\varphi(z) = \\sup \\{ \\Vert \\Psi(u)(z)\n\\Vert : u ~ \\text{is a unit vector in} ~ \\Gamma \\}\\).","PeriodicalId":0,"journal":{"name":"","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Approximately orthogonality preserving mappings on Hilbert \\\\(C_{0}(Z)\\\\)-modules\",\"authors\":\"M. Asadi, Zahra Hassanpour Yakhdani, Fatemeh Olyaninezhad, A. Sahleh\",\"doi\":\"10.3336/gm.57.1.05\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"In this paper, we will use the categorical approach to\\nHilbert \\\\(C^{\\\\ast}\\\\)-modules over a commutative \\\\(C^{\\\\ast}\\\\)-algebra\\nto investigate the approximately orthogonality preserving mappings\\non Hilbert \\\\(C^{\\\\ast}\\\\)-modules over a commutative\\n\\\\(C^{\\\\ast}\\\\)-algebra.\\n\\n Indeed, we show that if \\\\(\\\\Psi:\\\\Gamma \\\\rightarrow \\\\Gamma^{\\\\prime}\\n\\\\) is a nonzero \\\\( C_{0}(Z) \\\\)-linear\\n \\\\(( \\\\delta , \\\\varepsilon)\\\\)-orthogonality preserving mapping\\n between the continuous fields of Hilbert spaces on a locally\\ncompact Hausdorff space \\\\(Z\\\\), then \\\\(\\\\Psi\\\\) is injective, continuous\\nand also for every \\\\( x, y \\\\in \\\\Gamma \\\\) and \\\\(z \\\\in Z\\\\),\\n\\\\[\\n\\n\\n\\n\\\\vert\\n\\\\langle \\\\Psi(x),\\\\Psi(y) \\\\rangle(z) - \\\\varphi^2(z) \\\\langle x,y\\n\\\\rangle(z) \\\\vert \\\\leq \\\\frac{4(\\\\varepsilon -\\n\\\\delta)}{(1-\\\\delta)(1+\\\\varepsilon)} \\\\Vert \\\\Psi(x) \\\\Vert \\\\Vert\\n\\\\Psi(y) \\\\Vert,\\n\\n\\n\\\\]\\nwhere \\\\(\\\\varphi(z) = \\\\sup \\\\{ \\\\Vert \\\\Psi(u)(z)\\n\\\\Vert : u ~ \\\\text{is a unit vector in} ~ \\\\Gamma \\\\}\\\\).\",\"PeriodicalId\":0,\"journal\":{\"name\":\"\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":0.0,\"publicationDate\":\"2022-06-28\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"\",\"FirstCategoryId\":\"100\",\"ListUrlMain\":\"https://doi.org/10.3336/gm.57.1.05\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"","FirstCategoryId":"100","ListUrlMain":"https://doi.org/10.3336/gm.57.1.05","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
Approximately orthogonality preserving mappings on Hilbert \(C_{0}(Z)\)-modules
In this paper, we will use the categorical approach to
Hilbert \(C^{\ast}\)-modules over a commutative \(C^{\ast}\)-algebra
to investigate the approximately orthogonality preserving mappings
on Hilbert \(C^{\ast}\)-modules over a commutative
\(C^{\ast}\)-algebra.
Indeed, we show that if \(\Psi:\Gamma \rightarrow \Gamma^{\prime}
\) is a nonzero \( C_{0}(Z) \)-linear
\(( \delta , \varepsilon)\)-orthogonality preserving mapping
between the continuous fields of Hilbert spaces on a locally
compact Hausdorff space \(Z\), then \(\Psi\) is injective, continuous
and also for every \( x, y \in \Gamma \) and \(z \in Z\),
\[
\vert
\langle \Psi(x),\Psi(y) \rangle(z) - \varphi^2(z) \langle x,y
\rangle(z) \vert \leq \frac{4(\varepsilon -
\delta)}{(1-\delta)(1+\varepsilon)} \Vert \Psi(x) \Vert \Vert
\Psi(y) \Vert,
\]
where \(\varphi(z) = \sup \{ \Vert \Psi(u)(z)
\Vert : u ~ \text{is a unit vector in} ~ \Gamma \}\).