Results 1 to 10 of about 72 (54)

On the closure of the extended bicyclic semigroup

open access: yesKarpatsʹkì Matematičnì Publìkacìï, 2011
In the paper we study the semigroup $mathscr{C}_{mathbb{Z}}$which is a generalization of the bicyclic semigroup. We describemain algebraic properties of the semigroup$mathscr{C}_{mathbb{Z}}$ and prove that every non-trivialcongruence $mathfrak{C}$ on the
I. R. Fihel, O. V. Gutik
doaj   +5 more sources

The bicyclic semigroup hasP 4 *

open access: yesSemigroup Forum, 1993
A semigroup \(S\) is said to have the property \(P^*_ n\), where \(n > 1\) is an integer, if for any \(s_ 1,\dots,s_ n \in S\) there exist distinct permutations \(\sigma\), \(\tau\) in the symmetric group of degree \(n\) such that \[ s_{\sigma(1)} \dots s_{\sigma(n)} = s_{\tau(1)} \dots s_{\tau(n)}. \] \textit{J. Justin} and \textit{G.
Vachuska, C ., Vachuska, P.
exaly   +3 more sources

Embedding the bicyclic semigroup into countably compact topological semigroups

open access: yesTopology and Its Applications, 2010
We study algebraic and topological properties of topological semigroups containing a copy of the bicyclic semigroup C(p,q). We prove that each topological semigroup S with pseudocompact square contains no dense copy of C(p,q). On the other hand, we construct a (consistent) example of a pseudocompact (countably compact) Tychonov semigroup containing a ...
Taras Banakh, Oleg Gutik
exaly   +4 more sources

The α-bicyclic semigroup as a topological semigroup

open access: yesSemigroup Forum, 1984
C. Eberhart and J. Selden showed that the only Hausdorff topology on the bicyclic semigroup which makes it a topological semigroup is the discrete topology. A related result proved in this paper is the following: Let \(W_{\alpha}\) be the \(\alpha\)-bisimple semigroup. The only locally compact Hausdorff semigroup topology on \(W_{\alpha}\) is discrete.
exaly   +3 more sources

Hausdorff topologies on the α-bicyclic semigroup

open access: yesSemigroup Forum, 1987
The author presents a characterization of Hausdorff topologies on the \(\alpha\)-bicyclic semigroup \(W_{\alpha}\) under which \(W_{\alpha}\) is a topological inverse semigroup. Results and conditions are very technical in nature, and the author executes the steps necessary to expose these with substantial precision. The paper concludes with an example
exaly   +3 more sources

Identities in upper triangular tropical matrix semigroups and the bicyclic monoid [PDF]

open access: yesJournal of Algebra, 2018
We establish necessary and sufficient conditions for a semigroup identity to hold in the monoid of $n\times n$ upper triangular tropical matrices, in terms of equivalence of certain tropical polynomials. This leads to an algorithm for checking whether such an identity holds, in time polynomial in the length of the identity and size of the alphabet.
Laure Daviaud   +2 more
exaly   +6 more sources

A nonlocally compact nondiscrete topology for the α-bicyclic semigroup

open access: yesSemigroup Forum, 1985
For any ordinal number \(\alpha\), let \(H_{\alpha}\) be the set of ordinal numbers less than \(\omega^{\alpha}\). The \(\alpha\)-bicyclic semigroup is \(H_{\alpha}\times H_{\alpha}\) with the operation \[ (\beta,\gamma)(\delta,\eta)=(\beta +(\max (\gamma,\delta)-\gamma,\quad \eta +(\max (\gamma,\delta)-\delta), \] where \(+\) is ordinal addition.
Annie Selden
exaly   +2 more sources

On a semitopological semigroup $\boldsymbol{B}_{\omega}^{\mathscr{F}}$ when a family $\mathscr{F}$ consists of inductive non-empty subsets of $\omega$

open access: yesМатематичні Студії, 2023
Let $\boldsymbol{B}_{\omega}^{\mathscr{F}}$ be the bicyclic semigroup extension for the family $\mathscr{F}$ of ${\omega}$-closed subsets of $\omega$ which is introduced in \cite{Gutik-Mykhalenych=2020}.
O. V. Gutik, M. S. Mykhalenych
doaj   +1 more source

On endomorphisms of the bicyclic semigroup and the extended bicyclic semigroup

open access: yesVisnyk Lvivskogo Universytetu Seriya Mekhaniko-Matematychna, 2021
It is proved that the semigroups $\mathrm{\mathbf{End}}(\boldsymbol{B}_ω)$ and $\mathrm{\mathbf{End}}(\boldsymbol{B}_{\mathbb{Z}})$ of the endomorphisms of the bicyclic semigroup $\boldsymbol{B}_ω$ and the endomorphisms of the extended bicyclic semigroup $\boldsymbol{B}_{\mathbb{Z}}$ are isomorphic to the semidirect products $(ω,+)\rtimes_φ(ω,*)$ and $\
Gutik, Oleg   +2 more
openaire   +2 more sources

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