Results 1 to 10 of about 140 (43)

On an equivalence between regular ordered Γ-semigroups and regular ordered semigroups

open access: yesOpen Mathematics, 2020
In this paper, we develop a technique which enables us to obtain several results from the theory of Γ-semigroups as logical implications of their semigroup theoretical analogues.
Çullhaj Fabiana, Krakulli Anjeza
doaj   +1 more source

On extensions of completely simple semigroups by groups [PDF]

open access: yes, 2013
An example of an extension of a completely simple semigroup U by a group H is given which cannot be embedded into the wreath product of U by H. On the other hand, every central extension of U by H is shown to be embeddable in the wreath product of U by H,
Dékány, Tamás
core   +2 more sources

Cross-connections and variants of the full transformation semigroup [PDF]

open access: yes, 2017
Cross-connection theory propounded by K. S. S. Nambooripad describes the ideal structure of a regular semigroup using the categories of principal left (right) ideals.
Muhammed, P. A. Azeef
core   +1 more source

Idempotent rank in the endomorphism monoid of a non-uniform partition [PDF]

open access: yes, 2015
We calculate the rank and idempotent rank of the semigroup $E(X,P)$ generated by the idempotents of the semigroup $T(X,P)$, which consists of all transformations of the finite set $X$ preserving a non-uniform partition $P$. We also classify and enumerate
Dolinka, Igor   +2 more
core   +2 more sources

On the regularization of solution of an inverse ultraparabolic equation associated with perturbed final data [PDF]

open access: yes, 2014
In this paper, we study the inverse problem for a class of abstract ultraparabolic equations which is well-known to be ill-posed. We employ some elementary results of semi-group theory to present the formula of solution, then show the instability cause ...
Hung, Tran The   +3 more
core   +2 more sources

Special subgroups of regular semigroups [PDF]

open access: yes, 2016
This work was partially supported by the Portuguese Foundation for Science and Technology through the grant UID/MAT/00297/2013 (CMA).Extending the notions of inverse transversal and associate subgroup, we consider a regular semigroup S with the property ...
Almeida Santos, M. H., Blyth, T. S.
core   +1 more source

Adjoint regular rings

open access: yesInternational Journal of Mathematics and Mathematical Sciences, Volume 30, Issue 8, Page 459-466, 2002., 2002
Let R be a ring. The circle operation is the operation a∘b = a + b − ab, for all a, b ∈ R. This operation gives rise to a semigroup called the adjoint semigroup or circle semigroup of R. We investigate rings in which the adjoint semigroup is regular. Examples are given which illustrate and delimit the theory developed.
Henry E. Heatherly, Ralph P. Tucci
wiley   +1 more source

Ordered Regular Semigroups with Biggest Associates

open access: yesDiscussiones Mathematicae - General Algebra and Applications, 2019
We investigate the class BA of ordered regular semigroups in which each element has a biggest associate x† = max {y | xyx = x}. This class properly contains the class PO of principally ordered regular semigroups (in which there exists x⋆ = max {y | xyx ...
Blyth T.S., Santos M.H. Almeida
doaj   +1 more source

Infinite partition monoids [PDF]

open access: yes, 2014
Let $\mathcal P_X$ and $\mathcal S_X$ be the partition monoid and symmetric group on an infinite set $X$. We show that $\mathcal P_X$ may be generated by $\mathcal S_X$ together with two (but no fewer) additional partitions, and we classify the pairs ...
Banach S.   +8 more
core   +1 more source

Non-commutative finite monoids of a given order n ≥ 4

open access: yesAnalele Stiintifice ale Universitatii Ovidius Constanta: Seria Matematica, 2014
For a given integer n=p1α1p2α2⋯pkαk$n = p_1^{\alpha _1 } p_2^{\alpha _2 } \cdots p_k^{\alpha _k }$ (k ≥ 2), we give here a class of finitely presented finite monoids of order n. Indeed the monoids Mon(π), where π=〈a1,a2,…,ak|aipiαi=ai, (i=1,2,…,k),aiai+
Ahmadi B., Campbell C.M., Doostie H.
doaj   +1 more source

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