Linear Maps which Preserve or Strongly Preserve Weak Majorization

oleh: Mohammad Ali Vali, Ahmad Mohammad Hasani

Format: Article
Diterbitkan: SpringerOpen 2008-02-01

Deskripsi

For x,y∈â„Ân, we say x is weakly submajorized (weakly supermajorized) by y, and write x≺Éy (x≺Éy), if ∑1kx[i]≤∑1ky[i], k=1,2,…,n (∑1kx(i)≥∑1ky(i), k=1,2,…,n), where x[i] (x(i)) denotes the ith component of the vector x↓ (x↑) whose components are a decreasing (increasing) rearrangment of the components of x. We characterize the linear maps that preserve (strongly preserve) one of the majorizations ≺É or ≺É.