{"title":"关于有限群 m-semiregular 代表锦标赛的说明","authors":"Jia-Li Du","doi":"10.1016/j.jcta.2024.105952","DOIUrl":null,"url":null,"abstract":"<div><p>For a positive integer <em>m</em>, a group <em>G</em> is said to admit a <em>tournament m-semiregular representation</em> (T<em>m</em>SR for short) if there exists a tournament Γ such that the automorphism group of Γ is isomorphic to <em>G</em> and acts semiregularly on the vertex set of Γ with <em>m</em> orbits. It is easy to see that every finite group of even order does not admit a T<em>m</em>SR for any positive integer <em>m</em>. The T1SR is the well-known tournament regular representation (TRR for short). In 1970s, Babai and Imrich proved that every finite group of odd order admits a TRR except for <span><math><msubsup><mrow><mi>Z</mi></mrow><mrow><mn>3</mn></mrow><mrow><mn>2</mn></mrow></msubsup></math></span>, and every group (finite or infinite) without element of order 2 having an independent generating set admits a T2SR in (1979) <span><span>[3]</span></span>. Later, Godsil correct the result by showing that the only finite groups of odd order without a TRR are <span><math><msubsup><mrow><mi>Z</mi></mrow><mrow><mn>3</mn></mrow><mrow><mn>2</mn></mrow></msubsup></math></span> and <span><math><msubsup><mrow><mi>Z</mi></mrow><mrow><mn>3</mn></mrow><mrow><mn>3</mn></mrow></msubsup></math></span> by a probabilistic approach in (1986) <span><span>[11]</span></span>. In this note, it is shown that every finite group of odd order has a T<em>m</em>SR for every <span><math><mi>m</mi><mo>≥</mo><mn>2</mn></math></span>.</p></div>","PeriodicalId":50230,"journal":{"name":"Journal of Combinatorial Theory Series A","volume":"209 ","pages":"Article 105952"},"PeriodicalIF":0.9000,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0097316524000918/pdfft?md5=9f9703a561ce567e377942546fcc91e2&pid=1-s2.0-S0097316524000918-main.pdf","citationCount":"0","resultStr":"{\"title\":\"A note on tournament m-semiregular representations of finite groups\",\"authors\":\"Jia-Li Du\",\"doi\":\"10.1016/j.jcta.2024.105952\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>For a positive integer <em>m</em>, a group <em>G</em> is said to admit a <em>tournament m-semiregular representation</em> (T<em>m</em>SR for short) if there exists a tournament Γ such that the automorphism group of Γ is isomorphic to <em>G</em> and acts semiregularly on the vertex set of Γ with <em>m</em> orbits. It is easy to see that every finite group of even order does not admit a T<em>m</em>SR for any positive integer <em>m</em>. The T1SR is the well-known tournament regular representation (TRR for short). In 1970s, Babai and Imrich proved that every finite group of odd order admits a TRR except for <span><math><msubsup><mrow><mi>Z</mi></mrow><mrow><mn>3</mn></mrow><mrow><mn>2</mn></mrow></msubsup></math></span>, and every group (finite or infinite) without element of order 2 having an independent generating set admits a T2SR in (1979) <span><span>[3]</span></span>. Later, Godsil correct the result by showing that the only finite groups of odd order without a TRR are <span><math><msubsup><mrow><mi>Z</mi></mrow><mrow><mn>3</mn></mrow><mrow><mn>2</mn></mrow></msubsup></math></span> and <span><math><msubsup><mrow><mi>Z</mi></mrow><mrow><mn>3</mn></mrow><mrow><mn>3</mn></mrow></msubsup></math></span> by a probabilistic approach in (1986) <span><span>[11]</span></span>. In this note, it is shown that every finite group of odd order has a T<em>m</em>SR for every <span><math><mi>m</mi><mo>≥</mo><mn>2</mn></math></span>.</p></div>\",\"PeriodicalId\":50230,\"journal\":{\"name\":\"Journal of Combinatorial Theory Series A\",\"volume\":\"209 \",\"pages\":\"Article 105952\"},\"PeriodicalIF\":0.9000,\"publicationDate\":\"2024-09-04\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://www.sciencedirect.com/science/article/pii/S0097316524000918/pdfft?md5=9f9703a561ce567e377942546fcc91e2&pid=1-s2.0-S0097316524000918-main.pdf\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of Combinatorial Theory Series A\",\"FirstCategoryId\":\"100\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0097316524000918\",\"RegionNum\":2,\"RegionCategory\":\"数学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"MATHEMATICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Combinatorial Theory Series A","FirstCategoryId":"100","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0097316524000918","RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MATHEMATICS","Score":null,"Total":0}
A note on tournament m-semiregular representations of finite groups
For a positive integer m, a group G is said to admit a tournament m-semiregular representation (TmSR for short) if there exists a tournament Γ such that the automorphism group of Γ is isomorphic to G and acts semiregularly on the vertex set of Γ with m orbits. It is easy to see that every finite group of even order does not admit a TmSR for any positive integer m. The T1SR is the well-known tournament regular representation (TRR for short). In 1970s, Babai and Imrich proved that every finite group of odd order admits a TRR except for , and every group (finite or infinite) without element of order 2 having an independent generating set admits a T2SR in (1979) [3]. Later, Godsil correct the result by showing that the only finite groups of odd order without a TRR are and by a probabilistic approach in (1986) [11]. In this note, it is shown that every finite group of odd order has a TmSR for every .
期刊介绍:
The Journal of Combinatorial Theory publishes original mathematical research concerned with theoretical and physical aspects of the study of finite and discrete structures in all branches of science. Series A is concerned primarily with structures, designs, and applications of combinatorics and is a valuable tool for mathematicians and computer scientists.