English

On the elliptical range theorems for the Davis-Wielandt shell, the numerical range, and the conformal range

Spectral Theory 2026-03-10 v2

Abstract

We consider the elliptical range theorems for the Davis--Wielandt shell, the numerical range, and the conformal range in terms of and related to their quadratic representations. The emphasis is on exposing a variety of elementary approaches.

Keywords

Cite

@article{arxiv.2211.13145,
  title  = {On the elliptical range theorems for the Davis-Wielandt shell, the numerical range, and the conformal range},
  author = {Gyula Lakos},
  journal= {arXiv preprint arXiv:2211.13145},
  year   = {2026}
}