English

Invertible positive maps that are not automorphism

Functional Analysis 2026-05-15 v1

Abstract

Let XX be a real normed vector space with a cone KXK\subseteq X satisfying either (i) KK is closed with non-empty interior or (ii) KK has non-zero extremals or (iii) KK is closed and XX is a Banach space. In this short note, we provide a method to construct an invertible linear map T ⁣:XXT\colon X\to X such that T[K]KT[K]\subseteq K but T1[K]⊈ KT^{-1}[K]\not\subseteq~K. In particular, we show that, for every cone automorphism S ⁣:XXS\colon X\to X, there exists a rank one perturbation of SS which is positive and invertible, but does not have a positive inverse. We provide examples from four diverse situations.

Keywords

Cite

@article{arxiv.2605.14739,
  title  = {Invertible positive maps that are not automorphism},
  author = {Pavankumar Raickwade and K. C. Sivakumar},
  journal= {arXiv preprint arXiv:2605.14739},
  year   = {2026}
}

Comments

9 Pages

R2 v1 2026-07-22T07:12:13.943Z