3 papers
math.NA2026
Matrix nearness problems: Do real inputs admit real solutions?
Vanni Noferini, Matvei Zhukov
Given a real square matrix and a nonempty closed target set of complex matrices , invariant by complex conjugation and containing real matrices, does the subset of…
math.NA2026
Closest Normal Matrix Found Again Using Riemannian Optimization
Vanni Noferini, Matvei Zhukov
We propose an approach based on Riemannian optimization to compute a nearest normal matrix to a given one. The problem can be formulated as the minimization of a smooth function ei…
math.PR2025
Sharp constants relating the sub-Gaussian norm and the sub-Gaussian parameter
Lasse Leskelä, Matvei Zhukov
We determine the optimal constants in the classical inequalities relating the sub-Gaussian norm \(\|X\|_{ψ_2}\) and the sub-Gaussian parameter \(σ_X\) for centered real-valued rand…