Rank Properties of the Semigroup of Singular Transformations on a Finite Set
Titel:
Rank Properties of the Semigroup of Singular Transformations on a Finite Set
Auteur:
Ayık, Gonca Ayık, Hayrullah unlu, Yusuf Howie, John M.
Verschenen in:
Communications in algebra
Paginering:
Jaargang 36 (2008) nr. 7 pagina's 2581-2587
Jaar:
2008-07
Inhoud:
It is known that the semigroup Singn of all singular self-maps of Xn = {1,2,…, n} has rank n(n - 1)/2. The idempotent rank, defined as the smallest number of idempotents generating Singn, has the same value as the rank. (See Gomes and Howie, 1987.) Idempotents generating Singn can be seen as special cases (with m = r = 2) of (m, r)-path-cycles, as defined in Ay\i k et al. (2005). The object of this article is to show that, for fixed m and r, the (m, r)-rank of Singn, defined as the smallest number of (m, r)-path-cycles generating Singn, is once again n(n - 1)/2.