{"title":"小组的模同构问题——对Eick算法的再认识","authors":"Leo Margolis , Tobias Moede","doi":"10.1016/j.jaca.2022.100001","DOIUrl":null,"url":null,"abstract":"<div><p>We study the Modular Isomorphism Problem for groups of small order based on an improvement of an algorithm described by Eick. Our improvement allows to determine quotients <span><math><mi>I</mi><mo>(</mo><mi>k</mi><mi>G</mi><mo>)</mo><mo>/</mo><mi>I</mi><msup><mrow><mo>(</mo><mi>k</mi><mi>G</mi><mo>)</mo></mrow><mrow><mi>m</mi></mrow></msup></math></span> of the augmentation ideal without first computing the full augmentation ideal <span><math><mi>I</mi><mo>(</mo><mi>k</mi><mi>G</mi><mo>)</mo></math></span>. Our computations yield a positive answer to the MIP for groups of order 3<sup>7</sup> and strongly reduce the cases that need to be checked for groups of order 5<sup>6</sup>. We also show that the counterexamples to the Modular Isomorphism Problem found recently by García-Lucas, Margolis and del Río are the only 2- or 3-generated counterexamples of order 2<sup>9</sup>. Furthermore, we provide a proof for an observation of Bagiński, which is helpful in eliminating computationally difficult cases.</p></div>","PeriodicalId":100767,"journal":{"name":"Journal of Computational Algebra","volume":"1 ","pages":"Article 100001"},"PeriodicalIF":0.0000,"publicationDate":"2022-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2772827722000018/pdfft?md5=7c90799e7bad9a898c2e3d2a2e564ebc&pid=1-s2.0-S2772827722000018-main.pdf","citationCount":"7","resultStr":"{\"title\":\"The Modular Isomorphism Problem for small groups – revisiting Eick's algorithm\",\"authors\":\"Leo Margolis , Tobias Moede\",\"doi\":\"10.1016/j.jaca.2022.100001\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>We study the Modular Isomorphism Problem for groups of small order based on an improvement of an algorithm described by Eick. Our improvement allows to determine quotients <span><math><mi>I</mi><mo>(</mo><mi>k</mi><mi>G</mi><mo>)</mo><mo>/</mo><mi>I</mi><msup><mrow><mo>(</mo><mi>k</mi><mi>G</mi><mo>)</mo></mrow><mrow><mi>m</mi></mrow></msup></math></span> of the augmentation ideal without first computing the full augmentation ideal <span><math><mi>I</mi><mo>(</mo><mi>k</mi><mi>G</mi><mo>)</mo></math></span>. Our computations yield a positive answer to the MIP for groups of order 3<sup>7</sup> and strongly reduce the cases that need to be checked for groups of order 5<sup>6</sup>. We also show that the counterexamples to the Modular Isomorphism Problem found recently by García-Lucas, Margolis and del Río are the only 2- or 3-generated counterexamples of order 2<sup>9</sup>. Furthermore, we provide a proof for an observation of Bagiński, which is helpful in eliminating computationally difficult cases.</p></div>\",\"PeriodicalId\":100767,\"journal\":{\"name\":\"Journal of Computational Algebra\",\"volume\":\"1 \",\"pages\":\"Article 100001\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2022-06-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://www.sciencedirect.com/science/article/pii/S2772827722000018/pdfft?md5=7c90799e7bad9a898c2e3d2a2e564ebc&pid=1-s2.0-S2772827722000018-main.pdf\",\"citationCount\":\"7\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of Computational Algebra\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S2772827722000018\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Computational Algebra","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2772827722000018","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
The Modular Isomorphism Problem for small groups – revisiting Eick's algorithm
We study the Modular Isomorphism Problem for groups of small order based on an improvement of an algorithm described by Eick. Our improvement allows to determine quotients of the augmentation ideal without first computing the full augmentation ideal . Our computations yield a positive answer to the MIP for groups of order 37 and strongly reduce the cases that need to be checked for groups of order 56. We also show that the counterexamples to the Modular Isomorphism Problem found recently by García-Lucas, Margolis and del Río are the only 2- or 3-generated counterexamples of order 29. Furthermore, we provide a proof for an observation of Bagiński, which is helpful in eliminating computationally difficult cases.