English

The structured distance to ill-posedness for conic systems

Optimization and Control 2025-10-20 v1 Numerical Analysis Numerical Analysis

Abstract

An important measure of conditioning of a conic linear system is the size of the smallest structured perturbation making the system ill-posed. We show that this measure is unchanged if we restrict to perturbations of low rank. We thereby derive a broad generalization of the classical Eckart-Young result characterizing the distance to ill-posedness for a linear map.

Keywords

Cite

@article{arxiv.math/0309100,
  title  = {The structured distance to ill-posedness for conic systems},
  author = {Adrian S. Lewis},
  journal= {arXiv preprint arXiv:math/0309100},
  year   = {2025}
}

Comments

16 pages