On Kippenhahn curves of low rank partial isometries
Functional Analysis
2026-01-21 v1
Abstract
Conditions are established for rank three partial isometries to have circular components contained in their Kippenhahn curves. In particular, such matrices with circular numerical ranges are described. It is also established that the Gau-Wang-Wu conjecture holds for matrices under consideration.
Cite
@article{arxiv.2601.12923,
title = {On Kippenhahn curves of low rank partial isometries},
author = {Nikita Popov and Eric Shen and Ilya M. Spitkovsky},
journal= {arXiv preprint arXiv:2601.12923},
year = {2026}
}