Results 1 - 10 of 1,120

Decidable and undecidable problems related to completely 0-simple semigroups

by T. E. Hall, S. I. Kublanovskii, S. Margolis, M. V. Sapir, P. G. Trotter , 1996
"... The undecidable problems of the title are concerned with the question:- is a given finite semigroup embeddable in a given type of completely 0-simple semigroups? It is shown, for example, that the embeddability of a (finite) 3-nilpotent semigroup in a finite completely 0-simple semigroup is decidabl ..."
Abstract - Add to MetaCart
is decidable yet such embeddability is undecidable for a (finite) 4-nilpotent semigroup. As well the membership of the pseudovariety generated by finite completely 0-simple 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

by Kenneth Eriksson, Claes Johnson, Stig Larsson - 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 long-time integration without ..."
Abstract - Cited by 215 (3 self) - Add to MetaCart
. 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 long-time integration without

On finitely related semigroups

by Peter Mayr , 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, 3-nilpotent monoids, regular bands, semigroups with a single idemp ..."
Abstract - Add to MetaCart
idempotent, and Clifford semigroups. Further we provide the first example of a semigroup that is not finitely related: the 6-element 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 λ0-EXTENSIONS OF TOPOLOGICAL SEMIGROUPS

by Oleg Gutik, Kateryna Pavlyk
"... 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 ..."
Abstract - Add to MetaCart
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 q-theory of finite semigroups

by Benjamin Steinberg - 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 ..."
Abstract - Cited by 83 (31 self) - Add to MetaCart
to state-of-theart 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

Pseudo-amenability of Brandt semigroup algebras

by Maysam Maysami Sadr - 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 pseudo-amenable. ..."
Abstract - Cited by 1 (0 self) - Add to MetaCart
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 pseudo-amenable.

MORITA EQUIVALENCE OF BRANDT SEMIGROUP ALGEBRAS

by Maysam Maysami Sadr , 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 ..."
Abstract - Add to MetaCart
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 0-EXTENSIONS OF MONOIDS WITH ZERO

by unknown authors , 910
"... Abstract. We study algebraic properties of the Brandt λ 0-extensions of monoids with zero and non-trivial homomorphisms between the Brandt λ 0-extensions of monoids with zero. We introduce finite, compact topological Brandt λ 0-extensions of topological semigroups and countably compact topological B ..."
Abstract - Add to MetaCart
Abstract. We study algebraic properties of the Brandt λ 0-extensions of monoids with zero and non-trivial homomorphisms between the Brandt λ 0-extensions of monoids with zero. We introduce finite, compact topological Brandt λ 0-extensions of topological semigroups and countably compact topological

On semidirectly closed pseudovarieties of aperiodic semigroups

by M. Lurdes Teixeira - 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¤( ..."
Abstract - Cited by 2 (0 self) - Add to MetaCart
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

by Jean-Eric Pin , 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 ..."
Abstract - Cited by 54 (0 self) - Add to MetaCart
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 of 1,120