Strong linear preservers of symmetric doubly stochastic or doubly substochastic matrices
โ Scribed by Shwu-Huey Lin; Bit-Shun Tam
- Publisher
- Elsevier Science
- Year
- 2004
- Tongue
- English
- Weight
- 279 KB
- Volume
- 379
- Category
- Article
- ISSN
- 0024-3795
No coin nor oath required. For personal study only.
โฆ Synopsis
Let S denote either the set of n ร n symmetric doubly stochastic matrices or the set of n ร n symmetric doubly substochastic matrices and let T be a linear map on span S. We prove that T (S) = S if and only if there exists an n ร n permutation matrix P such that T (X) = P t XP for all X โ span S. Our proofs make use of the concept of neighborly extreme points of a polytope and depend on some intricate graph theory.
๐ SIMILAR VOLUMES
In this paper, we study the region s n of R n where the decreasingly ordered spectra of all the nรn symmetric doubly stochastic matrices lie with emphasis on the boundary set of s n . As applications, we study the case n = 4 and in particular we solve the inverse eigenvalue problem for 4ร4 symmetric