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Absolutely closed semigroups
Let [Formula: see text] be a class of topological semigroups. A semigroup X is called absolutely [Formula: see text] -closed if for any homomorphism [Formula: see text] to a topological semigroup [Formula: see text] , the image h[X] is closed in Y. Let [Formula: see text] , [Formula: see text] , and...
Autores principales: | , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Springer International Publishing
2023
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10632307/ https://www.ncbi.nlm.nih.gov/pubmed/37970590 http://dx.doi.org/10.1007/s13398-023-01519-2 |
Sumario: | Let [Formula: see text] be a class of topological semigroups. A semigroup X is called absolutely [Formula: see text] -closed if for any homomorphism [Formula: see text] to a topological semigroup [Formula: see text] , the image h[X] is closed in Y. Let [Formula: see text] , [Formula: see text] , and [Formula: see text] be the classes of [Formula: see text] , Hausdorff, and Tychonoff zero-dimensional topological semigroups, respectively. We prove that a commutative semigroup X is absolutely [Formula: see text] -closed if and only if X is absolutely [Formula: see text] -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 [Formula: see text] -closed if and only if X is finite. Also, for a given absolutely [Formula: see text] -closed semigroup X we detect absolutely [Formula: see text] -closed subsemigroups in the center of X. |
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