{"title":"广义矩阵环上群的部分作用","authors":"Dirceu Bagio , Héctor Pinedo","doi":"10.1016/j.jalgebra.2024.09.018","DOIUrl":null,"url":null,"abstract":"<div><div>Let <em>n</em> be a positive integer and <span><math><mi>R</mi><mo>=</mo><msub><mrow><mo>(</mo><msub><mrow><mi>M</mi></mrow><mrow><mi>i</mi><mi>j</mi></mrow></msub><mo>)</mo></mrow><mrow><mn>1</mn><mo>≤</mo><mi>i</mi><mo>,</mo><mi>j</mi><mo>≤</mo><mi>n</mi></mrow></msub></math></span> be a generalized matrix ring. For each <span><math><mn>1</mn><mo>≤</mo><mi>i</mi><mo>,</mo><mi>j</mi><mo>≤</mo><mi>n</mi></math></span>, let <span><math><msub><mrow><mi>I</mi></mrow><mrow><mi>i</mi></mrow></msub></math></span> be an ideal of the ring <span><math><msub><mrow><mi>R</mi></mrow><mrow><mi>i</mi></mrow></msub><mo>:</mo><mo>=</mo><msub><mrow><mi>M</mi></mrow><mrow><mi>i</mi><mi>i</mi></mrow></msub></math></span> and denote <span><math><msub><mrow><mi>I</mi></mrow><mrow><mi>i</mi><mi>j</mi></mrow></msub><mo>=</mo><msub><mrow><mi>I</mi></mrow><mrow><mi>i</mi></mrow></msub><msub><mrow><mi>M</mi></mrow><mrow><mi>i</mi><mi>j</mi></mrow></msub><mo>+</mo><msub><mrow><mi>M</mi></mrow><mrow><mi>i</mi><mi>j</mi></mrow></msub><msub><mrow><mi>I</mi></mrow><mrow><mi>j</mi></mrow></msub></math></span>. We give sufficient conditions for the subset <span><math><mi>I</mi><mo>=</mo><msub><mrow><mo>(</mo><msub><mrow><mi>I</mi></mrow><mrow><mi>i</mi><mi>j</mi></mrow></msub><mo>)</mo></mrow><mrow><mn>1</mn><mo>≤</mo><mi>i</mi><mo>,</mo><mi>j</mi><mo>≤</mo><mi>n</mi></mrow></msub></math></span> of <em>R</em> to be an ideal of <em>R</em>. Also, suppose that <span><math><msup><mrow><mi>α</mi></mrow><mrow><mo>(</mo><mi>i</mi><mo>)</mo></mrow></msup></math></span> is a partial action of a group <span>G</span> on <span><math><msub><mrow><mi>R</mi></mrow><mrow><mi>i</mi></mrow></msub></math></span>, for all <span><math><mn>1</mn><mo>≤</mo><mi>i</mi><mo>≤</mo><mi>n</mi></math></span>. We construct, under certain conditions, a partial action <em>γ</em> of <span>G</span> on <em>R</em> such that <em>γ</em> restricted to <span><math><msub><mrow><mi>R</mi></mrow><mrow><mi>i</mi></mrow></msub></math></span> coincides with <span><math><msup><mrow><mi>α</mi></mrow><mrow><mo>(</mo><mi>i</mi><mo>)</mo></mrow></msup></math></span>. We study the relation between this construction and the notion of Morita equivalent partial group action given in <span><span>[1]</span></span>. Moreover, we investigate properties related to Galois theory for the extension <span><math><msup><mrow><mi>R</mi></mrow><mrow><mi>γ</mi></mrow></msup><mo>⊂</mo><mi>R</mi></math></span>. Some examples to illustrate the results are considered in the last part of the paper.</div></div>","PeriodicalId":0,"journal":{"name":"","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Partial actions of groups on generalized matrix rings\",\"authors\":\"Dirceu Bagio , Héctor Pinedo\",\"doi\":\"10.1016/j.jalgebra.2024.09.018\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>Let <em>n</em> be a positive integer and <span><math><mi>R</mi><mo>=</mo><msub><mrow><mo>(</mo><msub><mrow><mi>M</mi></mrow><mrow><mi>i</mi><mi>j</mi></mrow></msub><mo>)</mo></mrow><mrow><mn>1</mn><mo>≤</mo><mi>i</mi><mo>,</mo><mi>j</mi><mo>≤</mo><mi>n</mi></mrow></msub></math></span> be a generalized matrix ring. For each <span><math><mn>1</mn><mo>≤</mo><mi>i</mi><mo>,</mo><mi>j</mi><mo>≤</mo><mi>n</mi></math></span>, let <span><math><msub><mrow><mi>I</mi></mrow><mrow><mi>i</mi></mrow></msub></math></span> be an ideal of the ring <span><math><msub><mrow><mi>R</mi></mrow><mrow><mi>i</mi></mrow></msub><mo>:</mo><mo>=</mo><msub><mrow><mi>M</mi></mrow><mrow><mi>i</mi><mi>i</mi></mrow></msub></math></span> and denote <span><math><msub><mrow><mi>I</mi></mrow><mrow><mi>i</mi><mi>j</mi></mrow></msub><mo>=</mo><msub><mrow><mi>I</mi></mrow><mrow><mi>i</mi></mrow></msub><msub><mrow><mi>M</mi></mrow><mrow><mi>i</mi><mi>j</mi></mrow></msub><mo>+</mo><msub><mrow><mi>M</mi></mrow><mrow><mi>i</mi><mi>j</mi></mrow></msub><msub><mrow><mi>I</mi></mrow><mrow><mi>j</mi></mrow></msub></math></span>. We give sufficient conditions for the subset <span><math><mi>I</mi><mo>=</mo><msub><mrow><mo>(</mo><msub><mrow><mi>I</mi></mrow><mrow><mi>i</mi><mi>j</mi></mrow></msub><mo>)</mo></mrow><mrow><mn>1</mn><mo>≤</mo><mi>i</mi><mo>,</mo><mi>j</mi><mo>≤</mo><mi>n</mi></mrow></msub></math></span> of <em>R</em> to be an ideal of <em>R</em>. Also, suppose that <span><math><msup><mrow><mi>α</mi></mrow><mrow><mo>(</mo><mi>i</mi><mo>)</mo></mrow></msup></math></span> is a partial action of a group <span>G</span> on <span><math><msub><mrow><mi>R</mi></mrow><mrow><mi>i</mi></mrow></msub></math></span>, for all <span><math><mn>1</mn><mo>≤</mo><mi>i</mi><mo>≤</mo><mi>n</mi></math></span>. We construct, under certain conditions, a partial action <em>γ</em> of <span>G</span> on <em>R</em> such that <em>γ</em> restricted to <span><math><msub><mrow><mi>R</mi></mrow><mrow><mi>i</mi></mrow></msub></math></span> coincides with <span><math><msup><mrow><mi>α</mi></mrow><mrow><mo>(</mo><mi>i</mi><mo>)</mo></mrow></msup></math></span>. We study the relation between this construction and the notion of Morita equivalent partial group action given in <span><span>[1]</span></span>. Moreover, we investigate properties related to Galois theory for the extension <span><math><msup><mrow><mi>R</mi></mrow><mrow><mi>γ</mi></mrow></msup><mo>⊂</mo><mi>R</mi></math></span>. Some examples to illustrate the results are considered in the last part of the paper.</div></div>\",\"PeriodicalId\":0,\"journal\":{\"name\":\"\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":0.0,\"publicationDate\":\"2024-10-11\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"\",\"FirstCategoryId\":\"100\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0021869324005258\",\"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://www.sciencedirect.com/science/article/pii/S0021869324005258","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
摘要
设 n 为正整数,R=(Mij)1≤i,j≤n 为广义矩阵环。对于每个 1≤i,j≤n,设 Ii 为环 Ri:=Mii 的理想,并表示 Iij=IiMij+MijIj 。我们给出了 R 的子集 I=(Iij)1≤i,j≤n 是 R 的理想的充分条件。同时,假设 α(i) 是一个群 G 对 Ri 的部分作用,对于所有 1≤i≤n。我们在一定条件下构造了 G 在 Ri 上的部分作用 γ,使得限制于 Ri 的 γ 与 α(i) 重合。我们将研究这一构造与 [1] 中给出的莫里塔等价部分群作用概念之间的关系。此外,我们还研究了扩展 Rγ⊂R 的伽罗瓦理论相关性质。本文的最后一部分列举了一些例子来说明这些结果。
Partial actions of groups on generalized matrix rings
Let n be a positive integer and be a generalized matrix ring. For each , let be an ideal of the ring and denote . We give sufficient conditions for the subset of R to be an ideal of R. Also, suppose that is a partial action of a group G on , for all . We construct, under certain conditions, a partial action γ of G on R such that γ restricted to coincides with . We study the relation between this construction and the notion of Morita equivalent partial group action given in [1]. Moreover, we investigate properties related to Galois theory for the extension . Some examples to illustrate the results are considered in the last part of the paper.