Linear algebra and matrix theory have long been fundamental tools in mathematical disciplines as well as fertile fields for research. In this book the authors present classical and recent results ofâ€¦ (More)

The question of which partial Hermitian matrices (some entries specified, some free) may be completed to positive definite matrices is addressed. It is shown that if the diagonal entries areâ€¦ (More)

mathematical development). These provide surveys with pleasant points of view and could be used as textual material in a number of contexts (e.g. undergraduate applied mathematics students in someâ€¦ (More)

Characterized are all simple undirected graphs G such that any real symmetric matrix that has graph G has no eigenvalues of multiplicity more than 2. All such graphs are partial 2-trees (and thisâ€¦ (More)

Given a nonnegative, symmetric matrix of weights, H , we study the problem of finding an Hermitian, positive semidefinite matrix which is closest to a given Hermitian matrix, A, with respect to theâ€¦ (More)