{"title":"绝对闭半群。","authors":"Taras Banakh, Serhii Bardyla","doi":"10.1007/s13398-023-01519-2","DOIUrl":null,"url":null,"abstract":"<p><p>Let <math><mi>C</mi></math> be a class of topological semigroups. A semigroup <i>X</i> is called <i>absolutely</i> <math><mi>C</mi></math><i>-closed</i> if for any homomorphism <math><mrow><mi>h</mi><mo>:</mo><mi>X</mi><mo>→</mo><mi>Y</mi></mrow></math> to a topological semigroup <math><mrow><mi>Y</mi><mo>∈</mo><mi>C</mi></mrow></math>, the image <i>h</i>[<i>X</i>] is closed in <i>Y</i>. Let <math><mrow><msub><mi>T</mi><mrow><mspace></mspace><mn>1</mn></mrow></msub><mi>S</mi></mrow></math>, <math><mrow><msub><mi>T</mi><mrow><mspace></mspace><mn>2</mn></mrow></msub><mi>S</mi></mrow></math>, and <math><mrow><msub><mi>T</mi><mrow><mspace></mspace><mi>z</mi></mrow></msub><mi>S</mi></mrow></math> be the classes of <math><msub><mi>T</mi><mn>1</mn></msub></math>, Hausdorff, and Tychonoff zero-dimensional topological semigroups, respectively. We prove that a commutative semigroup <i>X</i> is absolutely <math><mrow><msub><mi>T</mi><mrow><mspace></mspace><mi>z</mi></mrow></msub><mi>S</mi></mrow></math>-closed if and only if <i>X</i> is absolutely <math><mrow><msub><mi>T</mi><mrow><mspace></mspace><mn>2</mn></mrow></msub><mi>S</mi></mrow></math>-closed if and only if <i>X</i> is chain-finite, bounded, group-finite and Clifford + finite. On the other hand, a commutative semigroup <i>X</i> is absolutely <math><mrow><msub><mi>T</mi><mrow><mspace></mspace><mn>1</mn></mrow></msub><mi>S</mi></mrow></math>-closed if and only if <i>X</i> is finite. Also, for a given absolutely <math><mi>C</mi></math>-closed semigroup <i>X</i> we detect absolutely <math><mi>C</mi></math>-closed subsemigroups in the center of <i>X</i>.</p>","PeriodicalId":1,"journal":{"name":"Accounts of Chemical Research","volume":null,"pages":null},"PeriodicalIF":16.4000,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10632307/pdf/","citationCount":"0","resultStr":"{\"title\":\"Absolutely closed semigroups.\",\"authors\":\"Taras Banakh, Serhii Bardyla\",\"doi\":\"10.1007/s13398-023-01519-2\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><p>Let <math><mi>C</mi></math> be a class of topological semigroups. A semigroup <i>X</i> is called <i>absolutely</i> <math><mi>C</mi></math><i>-closed</i> if for any homomorphism <math><mrow><mi>h</mi><mo>:</mo><mi>X</mi><mo>→</mo><mi>Y</mi></mrow></math> to a topological semigroup <math><mrow><mi>Y</mi><mo>∈</mo><mi>C</mi></mrow></math>, the image <i>h</i>[<i>X</i>] is closed in <i>Y</i>. Let <math><mrow><msub><mi>T</mi><mrow><mspace></mspace><mn>1</mn></mrow></msub><mi>S</mi></mrow></math>, <math><mrow><msub><mi>T</mi><mrow><mspace></mspace><mn>2</mn></mrow></msub><mi>S</mi></mrow></math>, and <math><mrow><msub><mi>T</mi><mrow><mspace></mspace><mi>z</mi></mrow></msub><mi>S</mi></mrow></math> be the classes of <math><msub><mi>T</mi><mn>1</mn></msub></math>, Hausdorff, and Tychonoff zero-dimensional topological semigroups, respectively. We prove that a commutative semigroup <i>X</i> is absolutely <math><mrow><msub><mi>T</mi><mrow><mspace></mspace><mi>z</mi></mrow></msub><mi>S</mi></mrow></math>-closed if and only if <i>X</i> is absolutely <math><mrow><msub><mi>T</mi><mrow><mspace></mspace><mn>2</mn></mrow></msub><mi>S</mi></mrow></math>-closed if and only if <i>X</i> is chain-finite, bounded, group-finite and Clifford + finite. On the other hand, a commutative semigroup <i>X</i> is absolutely <math><mrow><msub><mi>T</mi><mrow><mspace></mspace><mn>1</mn></mrow></msub><mi>S</mi></mrow></math>-closed if and only if <i>X</i> is finite. Also, for a given absolutely <math><mi>C</mi></math>-closed semigroup <i>X</i> we detect absolutely <math><mi>C</mi></math>-closed subsemigroups in the center of <i>X</i>.</p>\",\"PeriodicalId\":1,\"journal\":{\"name\":\"Accounts of Chemical Research\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":16.4000,\"publicationDate\":\"2024-01-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10632307/pdf/\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Accounts of Chemical Research\",\"FirstCategoryId\":\"100\",\"ListUrlMain\":\"https://doi.org/10.1007/s13398-023-01519-2\",\"RegionNum\":1,\"RegionCategory\":\"化学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"2023/11/9 0:00:00\",\"PubModel\":\"Epub\",\"JCR\":\"Q1\",\"JCRName\":\"CHEMISTRY, MULTIDISCIPLINARY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Accounts of Chemical Research","FirstCategoryId":"100","ListUrlMain":"https://doi.org/10.1007/s13398-023-01519-2","RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2023/11/9 0:00:00","PubModel":"Epub","JCR":"Q1","JCRName":"CHEMISTRY, MULTIDISCIPLINARY","Score":null,"Total":0}
Let be a class of topological semigroups. A semigroup X is called absolutely-closed if for any homomorphism to a topological semigroup , the image h[X] is closed in Y. Let , , and be the classes of , Hausdorff, and Tychonoff zero-dimensional topological semigroups, respectively. We prove that a commutative semigroup X is absolutely -closed if and only if X is absolutely -closed if and only if X is chain-finite, bounded, group-finite and Clifford + finite. On the other hand, a commutative semigroup X is absolutely -closed if and only if X is finite. Also, for a given absolutely -closed semigroup X we detect absolutely -closed subsemigroups in the center of X.
期刊介绍:
Accounts of Chemical Research presents short, concise and critical articles offering easy-to-read overviews of basic research and applications in all areas of chemistry and biochemistry. These short reviews focus on research from the author’s own laboratory and are designed to teach the reader about a research project. In addition, Accounts of Chemical Research publishes commentaries that give an informed opinion on a current research problem. Special Issues online are devoted to a single topic of unusual activity and significance.
Accounts of Chemical Research replaces the traditional article abstract with an article "Conspectus." These entries synopsize the research affording the reader a closer look at the content and significance of an article. Through this provision of a more detailed description of the article contents, the Conspectus enhances the article's discoverability by search engines and the exposure for the research.