Abstract
In this paper we solve the inverse mean problem of contraharmonic and geometric means of positive definite matrices (proposed in [W.N. Anderson, M.E. Mays, T.D. Morley, G.E. Trapp, The contraharmonic mean of HSD matrices, SIAM J. Algebra Disc. Meth. 8 (1987) 674-682])A=X+Y-2(X-1+Y-1)-1,B=X#Y,by proving its equivalence to the well-known nonlinear matrix equation X = T - BX -1B where T=12(A+A#(A+8BA-1B)) is the unique positive definite solution of X = A + 2BX-1B. The inverse mean problem is solvable if and only if B ≤ A.
| Original language | English |
|---|---|
| Pages (from-to) | 221-229 |
| Number of pages | 9 |
| Journal | Linear Algebra and Its Applications |
| Volume | 408 |
| Issue number | 1-3 |
| DOIs | |
| State | Published - 1 Oct 2005 |
| Externally published | Yes |
Keywords
- Contraharmonic mean
- Geometric mean
- Inverse mean problem
- Nonlinear matrix equation
- Positive definite matrix