Abstract
Proposed by Oskar Maria Baksalary, Adam Mickiewicz University, Poznan, Poland, and Götz Trenkler, Technische Universität Dortmund, Dortmund,Germany. Let Cn,n denote the set of n x n complex matrices. Determine the shortest interval [a, b] such that if P and Q in Cn,n are nonzero orthogonal projectors, that is, Hermitian idempotent matrices, then all eigenvalues of PQ + QP belong to [a, b].
| Original language | English |
|---|---|
| Pages (from-to) | 746-747 |
| Journal | American Mathematical Monthly |
| Volume | 117 |
| Issue number | 8 |
| Publication status | Published - 2010 |