{"title":"带内卷的可表示正则环的直接有限性:一个反例","authors":"Christian Herrmann","doi":"arxiv-2408.16437","DOIUrl":null,"url":null,"abstract":"Bruns and Roddy constructed a $3$-generated modular ortholattice $L$ which\ncannot be embedded into any complete modular ortholattice. Motivated by their\napproach, we use shift operators to construct a $*$-regular $*$-ring $R$ of\nendomorphisms of an inner product space (which can be chosen as the Hilbert\nspace $\\ell^2$) such that direct finiteness fails for $R$.","PeriodicalId":501136,"journal":{"name":"arXiv - MATH - Rings and Algebras","volume":"53 1","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Direct finiteness of representable regular rings with involution: A counterexample\",\"authors\":\"Christian Herrmann\",\"doi\":\"arxiv-2408.16437\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Bruns and Roddy constructed a $3$-generated modular ortholattice $L$ which\\ncannot be embedded into any complete modular ortholattice. Motivated by their\\napproach, we use shift operators to construct a $*$-regular $*$-ring $R$ of\\nendomorphisms of an inner product space (which can be chosen as the Hilbert\\nspace $\\\\ell^2$) such that direct finiteness fails for $R$.\",\"PeriodicalId\":501136,\"journal\":{\"name\":\"arXiv - MATH - Rings and Algebras\",\"volume\":\"53 1\",\"pages\":\"\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2024-08-29\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"arXiv - MATH - Rings and Algebras\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/arxiv-2408.16437\",\"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 - Rings and Algebras","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/arxiv-2408.16437","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
Direct finiteness of representable regular rings with involution: A counterexample
Bruns and Roddy constructed a $3$-generated modular ortholattice $L$ which
cannot be embedded into any complete modular ortholattice. Motivated by their
approach, we use shift operators to construct a $*$-regular $*$-ring $R$ of
endomorphisms of an inner product space (which can be chosen as the Hilbert
space $\ell^2$) such that direct finiteness fails for $R$.