English

Disk matrices and the proximal mapping for the numerical radius

Optimization and Control 2020-05-01 v1

Abstract

Optimal matrices for problems involving the matrix numerical radius often have fields of values that are disks, a phenomenon associated with partial smoothness. Such matrices are highly structured: we experiment in particular with the proximal mapping for the radius, which often maps n-by-n random matrix inputs into a particular manifold of disk matrices that has real codimension 2n. The outputs, computed via semidefinite programming, also satisfy an unusual rank property at optimality.

Keywords

Cite

@article{arxiv.2004.14542,
  title  = {Disk matrices and the proximal mapping for the numerical radius},
  author = {X. Y. Han and Adrian S. Lewis},
  journal= {arXiv preprint arXiv:2004.14542},
  year   = {2020}
}

Comments

18 pages, 2 figures

R2 v1 2026-06-23T15:12:05.388Z