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Decidable and undecidable problems related to completely 0simple semigroups
, 1996
"... The undecidable problems of the title are concerned with the question: is a given finite semigroup embeddable in a given type of completely 0simple semigroups? It is shown, for example, that the embeddability of a (finite) 3nilpotent semigroup in a finite completely 0simple semigroup is decidabl ..."
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is decidable yet such embeddability is undecidable for a (finite) 4nilpotent semigroup. As well the membership of the pseudovariety generated by finite completely 0simple semigroups (or alternatively by finite Brandt semigroups) over groups from a pseudovariety of groups with decidable membership is shown
Adaptive Finite Element Methods For Parabolic Problems. VI. Analytic Semigroups
 SIAM J. Numer. Anal
, 1998
"... . We continue our work on adaptive finite element methods with a study of time discretization of analytic semigroups. We prove optimal a priori and a posteriori error estimates for the discontinuous Galerkin method showing, in particular, that analytic semigroups allow longtime integration without ..."
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Cited by 215 (3 self)
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. We continue our work on adaptive finite element methods with a study of time discretization of analytic semigroups. We prove optimal a priori and a posteriori error estimates for the discontinuous Galerkin method showing, in particular, that analytic semigroups allow longtime integration without
On finitely related semigroups
, 2012
"... An algebraic structure is finitely related (has finite degree) if its term functions are determined by some finite set of finitary relations. We show that the following finite semigroups are finitely related: commutative semigroups, 3nilpotent monoids, regular bands, semigroups with a single idemp ..."
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idempotent, and Clifford semigroups. Further we provide the first example of a semigroup that is not finitely related: the 6element Brandt monoid. This answers a question by Davey, Jackson, Pitkethly, and Szabó from Davey et al. (Semigroup Forum, 83(1):89–122, 2011).
ON COUNTABLY COMPACT BRANDT λ0EXTENSIONS OF TOPOLOGICAL SEMIGROUPS
"... All topological spaces will be assumed to be Hausdorff. We shall follow the terminology of [1, 2, 3]. A topological space X is called countably compact if any countable open cover of X contains a finite subcover [3]. A topological (inverse) semigroup is a Hausdorff topological space with a continuou ..."
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All topological spaces will be assumed to be Hausdorff. We shall follow the terminology of [1, 2, 3]. A topological space X is called countably compact if any countable open cover of X contains a finite subcover [3]. A topological (inverse) semigroup is a Hausdorff topological space with a
The qtheory of finite semigroups
 Ann. of Math
, 1968
"... When people are trying to learn mathematics for the purpose of research, they usually start at the forefront and then go backwards as needed in order to understand the results more fully. Yet with a mathematics book, it is not uncommon for people to start on page one and read onwards. This book is a ..."
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Cited by 83 (31 self)
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to stateoftheart Finite Semigroup Theory. There was the famous “Arbib ” book in the 1960s [165] containing the lectures of Kenneth Krohn, John Rhodes and Bret Tilson. Samuel Eilenberg’s treatise [82], with two chapters by Tilson [351,352], appeared over 30 years ago. It revolutionized semigroup theory
Pseudoamenability of Brandt semigroup algebras
 COMMENT.MATH.UNIV.CAROLIN. 50,3 (2009) 413–419
, 2009
"... In this paper it is shown that for a Brandt semigroup S over a group G with an arbitrary index set I, if G is amenable, then the Banach semigroup algebra ℓ1(S) is pseudoamenable. ..."
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Cited by 1 (0 self)
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In this paper it is shown that for a Brandt semigroup S over a group G with an arbitrary index set I, if G is amenable, then the Banach semigroup algebra ℓ1(S) is pseudoamenable.
MORITA EQUIVALENCE OF BRANDT SEMIGROUP ALGEBRAS
, 2008
"... We prove that for every group G and any two sets I, J, the Brandt semigroup algebras ℓ 1 (B(I, G)) and ℓ 1 (B(J, G)) are Morita equivalent with respect to the Morita theory of selfinduced Banach algebras introduced by Grønbæk. As applications, we show that if G is an amenable group, then for a wide ..."
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We prove that for every group G and any two sets I, J, the Brandt semigroup algebras ℓ 1 (B(I, G)) and ℓ 1 (B(J, G)) are Morita equivalent with respect to the Morita theory of selfinduced Banach algebras introduced by Grønbæk. As applications, we show that if G is an amenable group, then for a
ON THE BRANDT λ 0EXTENSIONS OF MONOIDS WITH ZERO
, 910
"... Abstract. We study algebraic properties of the Brandt λ 0extensions of monoids with zero and nontrivial homomorphisms between the Brandt λ 0extensions of monoids with zero. We introduce finite, compact topological Brandt λ 0extensions of topological semigroups and countably compact topological B ..."
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Abstract. We study algebraic properties of the Brandt λ 0extensions of monoids with zero and nontrivial homomorphisms between the Brandt λ 0extensions of monoids with zero. We introduce finite, compact topological Brandt λ 0extensions of topological semigroups and countably compact topological
On semidirectly closed pseudovarieties of aperiodic semigroups
 J. Pure Appl. Algebra
"... Abstract. This paper presents a study of the semidirectly closed pseudovariety generated by the aperiodic Brandt semigroup B2, denoted V¤(B2). We construct a basis of pseudoidentities for the semidirect powers of the pseudovariety generated by B2 which leads to the main result, which states that V¤( ..."
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Cited by 2 (0 self)
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Abstract. This paper presents a study of the semidirectly closed pseudovariety generated by the aperiodic Brandt semigroup B2, denoted V¤(B2). We construct a basis of pseudoidentities for the semidirect powers of the pseudovariety generated by B2 which leads to the main result, which states that V
Syntactic Semigroups
, 1997
"... Introduction This chapter gives an overview on what is often called the algebraic theory of finite automata. It deals with languages, automata and semigroups, and has connections with model theory in logic, boolean circuits, symbolic dynamics and topology. Kleene's theorem [70] is usually con ..."
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Cited by 54 (0 self)
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Introduction This chapter gives an overview on what is often called the algebraic theory of finite automata. It deals with languages, automata and semigroups, and has connections with model theory in logic, boolean circuits, symbolic dynamics and topology. Kleene's theorem [70] is usually
Results 1  10
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