Any extension of a group A by a group B can be embedded in their wreath product A Wr B. Here we consider generalizations of this result for inverse semigroups.Suppose S is an inverse semigroup and ρ0 is a congruence on S. We put T = S/ρ0 and denote the natural map from S to T by ρ. The kernel of ρ is the inverse image ETρ−1 of the semilattice ET of idempotents of T. First we show that if each ρ0-class of idempotents of S is inversely well-ordered, then S can be embedded in K Wr T, the standard wreath product of K and T. In general, not all elements of K Wr T have inverses. However, we can define a wreath product W(K, T) which is an inverse semigroup and which contains S when the previous condition holds. If ρ0 is idempotent-separating and S is 0-bisimple, K is the union of zero and a family of isomorphic groups. In this case, we can replace K by a single component group G of K, augmented by zero, and show that S can be embedded in W(G0, T). These results are analogous to the extension theories of D'Alarcao [1] and Munn [3] and they give conditions under which all inverse semigroup extensions of an inverse semigroup A by an inverse semigroup T are contained in a semigroup with structure depending only on A and T.
Houghton, C. H. Embedding inverse semigroups in wreath products. Glasgow mathematical journal, Tome 17 (1976) no. 2, pp. 77-82. doi: 10.1017/S0017089500002767
@article{10_1017_S0017089500002767,
author = {Houghton, C. H.},
title = {Embedding inverse semigroups in wreath products},
journal = {Glasgow mathematical journal},
pages = {77--82},
year = {1976},
volume = {17},
number = {2},
doi = {10.1017/S0017089500002767},
url = {http://geodesic.mathdoc.fr/articles/10.1017/S0017089500002767/}
}
TY - JOUR
AU - Houghton, C. H.
TI - Embedding inverse semigroups in wreath products
JO - Glasgow mathematical journal
PY - 1976
SP - 77
EP - 82
VL - 17
IS - 2
UR - http://geodesic.mathdoc.fr/articles/10.1017/S0017089500002767/
DO - 10.1017/S0017089500002767
ID - 10_1017_S0017089500002767
ER -