3 papers
math.NA2026
Nearest matrix with multiple eigenvalues by Riemannian optimization
Vanni Noferini, Lauri Nyman, Federico Poloni
Given a square complex matrix , we tackle the problem of finding the nearest matrix with multiple eigenvalues or, equivalently when had distinct eigenvalues, the nearest def…
math.NA2026
Structured distance to singularity as a nonlinear system of equations
Miryam Gnazzo, Nicola Guglielmi, Federico Poloni +1
In this article we study the structured distance to singularity for a nonsingular matrix , with a prescribed linear structure (for instanc…
math.NA2025
Riemann-Oracle: A general-purpose Riemannian optimizer to solve nearness problems in matrix theory
Miryam Gnazzo, Vanni Noferini, Lauri Nyman +1
We propose an extremely versatile approach to address a large family of matrix nearness problems, possibly with additional linear constraints. Our method is based on splitting a ma…