Perturbation bounds for eigenvalues of diagonalizable matrices are derived that do not depend on any quantities associated with the perturbed matrix; in particular the perturbed matrix can be defective. Furthermore, Gerschgorin-like inclusion regions in the Frobenius are derived, as well as bounds on the departure from normality. 1. Introduction. The results in this paper are based on two eigen...

The Hermite Normal Form is a canonical matrix analogue of Reduced Echelon Form, but involving matrices over more general rings. In this work we formalise an algorithm to compute the Hermite Normal Form of a matrix by means of elementary row operations, taking advantage of the Echelon Form AFP entry. We have proven the correctness of such an algorithm and refined it to immutable arrays. Furtherm...

Smith normal form evaluations found by Bessenrodt and Stanley for some Hankel matrices of q-Catalan numbers are proven in two ways. One argument generalizes the Bessenrodt–Stanley results for the Smith normal form of a certain multivariate matrix that refines one studied by Berlekamp, Carlitz, Roselle, and Scoville. The second argument, which uses orthogonal polynomials, generalizes to a number...

We introduce the notion of a "short normal path" between matrices S and T, that is, a continuous path from S to T consisting of normal matrices and having the same length as the straight line path from S to T. By this means we prove that for certain normal matrices S and T the eigenvalues of S and T may be paired in such a way that the maximum distance (in the complex plane) between the pairs i...

Let $a, b, k,in K$ and $u, v in U(K)$. We show for any idempotent $ein K$, $(a 0|b 0)$ is e-clean iff $(a 0|u(vb + ka) 0)$ is e-clean and if $(a 0|b 0)$ is 0-clean, $(ua 0|u(vb + ka) 0)$ is too.