Results 21 to 30 of about 140 (43)
The algebra of adjacency patterns: Rees matrix semigroups with reversion [PDF]
, 2009 We establish a surprisingly close relationship between universal Horn classes of directed graphs and varieties generated by so-called adjacency semigroups which are Rees matrix semigroups over the trivial group with the unary operation of reversion.
D.M. Clark +18 more
core +2 more sources
The classification of partition homogeneous groups with applications to semigroup theory [PDF]
, 2016 Let λ=(λ1,λ2,...) be a partition of n, a sequence of positive integers in non-increasing order with sum n. Let Ω:={1,...,n}. An ordered partition P=(A1,A2,...) of Ω has type λ if |Ai|=λi.Following Martin and Sagan, we say that G is λ-transitive if, for ...
André, Jorge +2 more
core +2 more sources
Enumeration of idempotents in planar diagram monoids [PDF]
, 2018 We classify and enumerate the idempotents in several planar diagram monoids: namely, the Motzkin, Jones (a.k.a. Temperley-Lieb) and Kauffman monoids.
Dolinka, Igor +7 more
core +2 more sources
Variants of finite full transformation semigroups
, 2015 The variant of a semigroup S with respect to an element a in S, denoted S^a, is the semigroup with underlying set S and operation * defined by x*y=xay for x,y in S.
Dolinka, Igor, East, James
core +1 more source
Faithful linear representations of bands [PDF]
, 2009 A band is a semigroup consisting of idempotents. It is proved that for any field K and any band S with finitely many components, the semigroup algebra K [S] can be embedded in upper triangular matrices over a commutative K-algebra. The proof of a theorem
Cedó, Ferran, Okniński, Jan
core +2 more sources
Motzkin monoids and partial Brauer monoids [PDF]
, 2016 We study the partial Brauer monoid and its planar submonoid, the Motzkin monoid. We conduct a thorough investigation of the structure of both monoids, providing information on normal forms, Green's relations, regularity, ideals, idempotent generation ...
Aigner +78 more
core +2 more sources
A family of varieties of pseudosemilattices
, 2013 In [3], a basis of identities {u_n = v_n | n\geq 2} for the variety SPS of all strict pseudosemilattices was determined. Each one of these identities u_n = v_n has a peculiar 2-content D_n.
Oliveira, Luis
core +1 more source
Diagram monoids and Graham–Houghton graphs: Idempotents and generating sets of ideals [PDF]
, 2016 We study the ideals of the partition, Brauer, and Jones monoid, establishing various combinatorial results on generating sets and idempotent generating sets via an analysis of their Graham–Houghton graphs.
East, James, Gray, Robert D.
core +2 more sources
Sandwich semigroups in locally small categories I: Foundations
, 2018 Fix (not necessarily distinct) objects $i$ and $j$ of a locally small category $S$, and write $S_{ij}$ for the set of all morphisms $i\to j$. Fix a morphism $a\in S_{ji}$, and define an operation $\star_a$ on $S_{ij}$ by $x\star_ay=xay$ for all $x,y\in ...
Dolinka, Igor +6 more
core +1 more source
A note on embedding of semigroup amalgams [PDF]
, 2014 We give necessary conditions for the embedding of completely regular semigroup, Clifford semigroup and commutative regular semigroup ...
Rahkema, Kristiina, Sohail, Nasir
core +2 more sources