Subspace Semigroups
✍ Scribed by Jan Okniński; Mohan S. Putcha
- Publisher
- Elsevier Science
- Year
- 2000
- Tongue
- English
- Weight
- 134 KB
- Volume
- 233
- Category
- Article
- ISSN
- 0021-8693
No coin nor oath required. For personal study only.
✦ Synopsis
For a finite dimensional algebra A over an infinite field K, the subspace Ž . Ž . semigroup S S A consists of all subspaces of A with operation V )W s lin VW .
K
Ž .
We describe the structure of S S A , showing in particular that, similarly to any Ž . algebraic linear semigroup, S S A is strongly -regular; we describe its regular elements and regular T T-classes. As the key intermediate step, for an arbitrary Ž . connected algebraic monoid M, we study the semigroup C C M consisting of all irreducible closed subsets with operation X и Y s XY, and we transfer the informa-Ž . Ž . Ž . tion to S S A via the natural onto homomorphism C C A ª S S A . With potential applications in mind, our primary focus in this paper is on the case of the full Ž . matrix algebra A s M K .
📜 SIMILAR VOLUMES
It is proved that any multiplicative semigroup consisting of compact quasinilpotent operators on a Banach space is triangularizable. The consequences are discussed.
269 305) that a semigroup of matrices is triangularizable if the ranks of all the commutators of elements of the semigroup are at most 1. Our main theorem is an extension of this result to semigroups of algebraic operators on a Banach space. We also obtain a related theorem for a pair [A, B] of arbi