A softer, stronger Lidskii theorem
Let A, B be selfadjoint matrices. The theorem of Lidskii relates the eigenvalues of A-B to those of A and B. The authors introduce a notion of weak majorization (their ``soft'' inequalities) and use it to study the relations among the eigenvalues of A, B, and A-B and the behavior of weakly unitarily invariant norms.
scientific article; zbMATH DE number 4105132
scientific article