Gerardo M. Escolano, Antonio M. Peralta, Armando R. Villena
{"title":"算子交换性的保全器","authors":"Gerardo M. Escolano, Antonio M. Peralta, Armando R. Villena","doi":"arxiv-2409.06799","DOIUrl":null,"url":null,"abstract":"Let $\\mathfrak{M}$ and $\\mathfrak{J}$ be JBW$^*$-algebras admitting no\ncentral summands of type $I_1$ and $I_2,$ and let $\\Phi: \\mathfrak{M}\n\\rightarrow \\mathfrak{J}$ be a linear bijection preserving operator\ncommutativity in both directions, that is, $$[x,\\mathfrak{M},y] = 0\n\\Leftrightarrow [\\Phi(x),\\mathfrak{J},\\Phi(y)] = 0,$$ for all $x,y\\in\n\\mathfrak{M}$, where the associator of three elements $a,b,c$ in $\\mathfrak{M}$\nis defined by $[a,b,c]:=(a\\circ b)\\circ c - (c\\circ b)\\circ a$. We prove that\nunder these conditions there exist a unique invertible central element $z_0$ in\n$\\mathfrak{J}$, a unique Jordan isomorphism $J: \\mathfrak{M} \\rightarrow\n\\mathfrak{J}$, and a unique linear mapping $\\beta$ from $\\mathfrak{M}$ to the\ncentre of $\\mathfrak{J}$ satisfying $$ \\Phi(x) = z_0 \\circ J(x) + \\beta(x), $$\nfor all $x\\in \\mathfrak{M}.$ Furthermore, if $\\Phi$ is a symmetric mapping\n(i.e., $\\Phi (x^*) = \\Phi (x)^*$ for all $x\\in \\mathfrak{M}$), the element\n$z_0$ is self-adjoint, $J$ is a Jordan $^*$-isomorphism, and $\\beta$ is a\nsymmetric mapping too. In case that $\\mathfrak{J}$ is a JBW$^*$-algebra admitting no central\nsummands of type $I_1$, we also address the problem of describing the form of\nall symmetric bilinear mappings $B : \\mathfrak{J}\\times \\mathfrak{J}\\to\n\\mathfrak{J}$ whose trace is associating (i.e., $[B(a,a),b,a] = 0,$ for all $a,\nb \\in \\mathfrak{J})$ providing a complete solution to it. We also determine the\nform of all associating linear maps on $\\mathfrak{J}$.","PeriodicalId":501114,"journal":{"name":"arXiv - MATH - Operator Algebras","volume":"2 1","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Preservers of Operator Commutativity\",\"authors\":\"Gerardo M. Escolano, Antonio M. Peralta, Armando R. Villena\",\"doi\":\"arxiv-2409.06799\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Let $\\\\mathfrak{M}$ and $\\\\mathfrak{J}$ be JBW$^*$-algebras admitting no\\ncentral summands of type $I_1$ and $I_2,$ and let $\\\\Phi: \\\\mathfrak{M}\\n\\\\rightarrow \\\\mathfrak{J}$ be a linear bijection preserving operator\\ncommutativity in both directions, that is, $$[x,\\\\mathfrak{M},y] = 0\\n\\\\Leftrightarrow [\\\\Phi(x),\\\\mathfrak{J},\\\\Phi(y)] = 0,$$ for all $x,y\\\\in\\n\\\\mathfrak{M}$, where the associator of three elements $a,b,c$ in $\\\\mathfrak{M}$\\nis defined by $[a,b,c]:=(a\\\\circ b)\\\\circ c - (c\\\\circ b)\\\\circ a$. We prove that\\nunder these conditions there exist a unique invertible central element $z_0$ in\\n$\\\\mathfrak{J}$, a unique Jordan isomorphism $J: \\\\mathfrak{M} \\\\rightarrow\\n\\\\mathfrak{J}$, and a unique linear mapping $\\\\beta$ from $\\\\mathfrak{M}$ to the\\ncentre of $\\\\mathfrak{J}$ satisfying $$ \\\\Phi(x) = z_0 \\\\circ J(x) + \\\\beta(x), $$\\nfor all $x\\\\in \\\\mathfrak{M}.$ Furthermore, if $\\\\Phi$ is a symmetric mapping\\n(i.e., $\\\\Phi (x^*) = \\\\Phi (x)^*$ for all $x\\\\in \\\\mathfrak{M}$), the element\\n$z_0$ is self-adjoint, $J$ is a Jordan $^*$-isomorphism, and $\\\\beta$ is a\\nsymmetric mapping too. In case that $\\\\mathfrak{J}$ is a JBW$^*$-algebra admitting no central\\nsummands of type $I_1$, we also address the problem of describing the form of\\nall symmetric bilinear mappings $B : \\\\mathfrak{J}\\\\times \\\\mathfrak{J}\\\\to\\n\\\\mathfrak{J}$ whose trace is associating (i.e., $[B(a,a),b,a] = 0,$ for all $a,\\nb \\\\in \\\\mathfrak{J})$ providing a complete solution to it. We also determine the\\nform of all associating linear maps on $\\\\mathfrak{J}$.\",\"PeriodicalId\":501114,\"journal\":{\"name\":\"arXiv - MATH - Operator Algebras\",\"volume\":\"2 1\",\"pages\":\"\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2024-09-10\",\"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-2409.06799\",\"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-2409.06799","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
Let $\mathfrak{M}$ and $\mathfrak{J}$ be JBW$^*$-algebras admitting no
central summands of type $I_1$ and $I_2,$ and let $\Phi: \mathfrak{M}
\rightarrow \mathfrak{J}$ be a linear bijection preserving operator
commutativity in both directions, that is, $$[x,\mathfrak{M},y] = 0
\Leftrightarrow [\Phi(x),\mathfrak{J},\Phi(y)] = 0,$$ for all $x,y\in
\mathfrak{M}$, where the associator of three elements $a,b,c$ in $\mathfrak{M}$
is defined by $[a,b,c]:=(a\circ b)\circ c - (c\circ b)\circ a$. We prove that
under these conditions there exist a unique invertible central element $z_0$ in
$\mathfrak{J}$, a unique Jordan isomorphism $J: \mathfrak{M} \rightarrow
\mathfrak{J}$, and a unique linear mapping $\beta$ from $\mathfrak{M}$ to the
centre of $\mathfrak{J}$ satisfying $$ \Phi(x) = z_0 \circ J(x) + \beta(x), $$
for all $x\in \mathfrak{M}.$ Furthermore, if $\Phi$ is a symmetric mapping
(i.e., $\Phi (x^*) = \Phi (x)^*$ for all $x\in \mathfrak{M}$), the element
$z_0$ is self-adjoint, $J$ is a Jordan $^*$-isomorphism, and $\beta$ is a
symmetric mapping too. In case that $\mathfrak{J}$ is a JBW$^*$-algebra admitting no central
summands of type $I_1$, we also address the problem of describing the form of
all symmetric bilinear mappings $B : \mathfrak{J}\times \mathfrak{J}\to
\mathfrak{J}$ whose trace is associating (i.e., $[B(a,a),b,a] = 0,$ for all $a,
b \in \mathfrak{J})$ providing a complete solution to it. We also determine the
form of all associating linear maps on $\mathfrak{J}$.