Abstract
Let Mn be the space of n × n complex matrices. For A ∈ Mn, let s(A) ≡ (s1(A), . . . , Sn(A)), where s1(A) ≥ ⋯ ≥ Sn(A) are the singular values of A. We prove that if A, B ∈ Mn are positive semidefinite, then (i) sj(A - B) ≤ sj(A ⊕ B), j = 1,2, . . . , n, and (ii) the weak log-majorization relations s(A-|z|B) ≺wlog s(A+zB) ≺wlog s(A + \z\B) hold for any complex number z. This sharpens some results due to R. Bhatia and F. Kittaneh.
| Original language | English |
|---|---|
| Pages (from-to) | 819-823 |
| Number of pages | 5 |
| Journal | SIAM Journal on Matrix Analysis and Applications |
| Volume | 22 |
| Issue number | 3 |
| DOIs | |
| State | Published - Oct 2000 |
| Externally published | Yes |
Keywords
- Majorization
- Positive semidefinite matrices
- Singular values
- Unitarily invariant norms