The Horn conjecture for sums of compact selfadjoint operators. (English) Zbl 1205.47022
Given three decreasing sequences with limit zero, the authors characterize, in terms of Horn type inequalities, when there exist two compact positive operators such that the given sequences are the sets of eigenvalues of the two operators and of their sum, respectively. Also, finite sums of compact selfadjoint operators are considered.
Reviewer: Jaroslav Zemánek (Warszawa)
MSC:
47B06 | Riesz operators; eigenvalue distributions; approximation numbers, \(s\)-numbers, Kolmogorov numbers, entropy numbers, etc. of operators |