{"title":"具有约当积性质的双线性映射","authors":"Jorge J. Garcés , Mykola Khrypchenko","doi":"10.1016/j.laa.2025.09.013","DOIUrl":null,"url":null,"abstract":"<div><div>We study symmetric continuous bilinear maps <em>V</em> on a C<sup>⁎</sup> -algebra <em>A</em> that have the Jordan product property at a fixed element <span><math><mi>z</mi><mo>∈</mo><mi>A</mi></math></span>. We show that, whenever <em>A</em> is a finite direct sum of infinite simple von Neumann algebras, such a map <em>V</em> has the square-zero property. Then, it is proved that <span><math><mi>V</mi><mo>(</mo><mi>a</mi><mo>,</mo><mi>b</mi><mo>)</mo><mo>=</mo><mi>T</mi><mo>(</mo><mi>a</mi><mo>∘</mo><mi>b</mi><mo>)</mo></math></span> for some bounded linear map <em>T</em> on <em>A</em>. As a consequence, Jordan homomorphisms and derivations at <span><math><mi>z</mi><mo>∈</mo><mi>A</mi></math></span> are characterized.</div></div>","PeriodicalId":18043,"journal":{"name":"Linear Algebra and its Applications","volume":"728 ","pages":"Pages 435-448"},"PeriodicalIF":1.1000,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Bilinear maps having Jordan product property\",\"authors\":\"Jorge J. Garcés , Mykola Khrypchenko\",\"doi\":\"10.1016/j.laa.2025.09.013\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>We study symmetric continuous bilinear maps <em>V</em> on a C<sup>⁎</sup> -algebra <em>A</em> that have the Jordan product property at a fixed element <span><math><mi>z</mi><mo>∈</mo><mi>A</mi></math></span>. We show that, whenever <em>A</em> is a finite direct sum of infinite simple von Neumann algebras, such a map <em>V</em> has the square-zero property. Then, it is proved that <span><math><mi>V</mi><mo>(</mo><mi>a</mi><mo>,</mo><mi>b</mi><mo>)</mo><mo>=</mo><mi>T</mi><mo>(</mo><mi>a</mi><mo>∘</mo><mi>b</mi><mo>)</mo></math></span> for some bounded linear map <em>T</em> on <em>A</em>. As a consequence, Jordan homomorphisms and derivations at <span><math><mi>z</mi><mo>∈</mo><mi>A</mi></math></span> are characterized.</div></div>\",\"PeriodicalId\":18043,\"journal\":{\"name\":\"Linear Algebra and its Applications\",\"volume\":\"728 \",\"pages\":\"Pages 435-448\"},\"PeriodicalIF\":1.1000,\"publicationDate\":\"2025-09-23\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Linear Algebra and its Applications\",\"FirstCategoryId\":\"100\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0024379525003866\",\"RegionNum\":3,\"RegionCategory\":\"数学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"MATHEMATICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Linear Algebra and its Applications","FirstCategoryId":"100","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0024379525003866","RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MATHEMATICS","Score":null,"Total":0}
We study symmetric continuous bilinear maps V on a C⁎ -algebra A that have the Jordan product property at a fixed element . We show that, whenever A is a finite direct sum of infinite simple von Neumann algebras, such a map V has the square-zero property. Then, it is proved that for some bounded linear map T on A. As a consequence, Jordan homomorphisms and derivations at are characterized.
期刊介绍:
Linear Algebra and its Applications publishes articles that contribute new information or new insights to matrix theory and finite dimensional linear algebra in their algebraic, arithmetic, combinatorial, geometric, or numerical aspects. It also publishes articles that give significant applications of matrix theory or linear algebra to other branches of mathematics and to other sciences. Articles that provide new information or perspectives on the historical development of matrix theory and linear algebra are also welcome. Expository articles which can serve as an introduction to a subject for workers in related areas and which bring one to the frontiers of research are encouraged. Reviews of books are published occasionally as are conference reports that provide an historical record of major meetings on matrix theory and linear algebra.