中文

实C*代数上单完全积分类映射的C*-极点

算子代数 2025-09-30 v2 泛函分析

摘要

本文研究了CC^*-凸集UCP(A,B(H))\mathrm{UCP}(\mathcal{A},B(\mathcal{H}))中所有单完全积(complete positive, UCP)映射的实C*-极点的一般性质和结构。我们分析了实C*代数情况与复C*代数情况之间C*-极点结构的差异。特别地,我们证明了矩阵代数之间的UCP映射为C*-极点的必要充分条件在实和复矩阵代数情况下是相同的。我们还注意到,当A\mathcal{A}是交换实C*代数时,与当A\mathcal{A}是交换复C*代数时,C*-极点结构存在显著差异。我们对A\mathcal{A}为单部交换实C*代数且H\mathcal{H}为有限维实希尔伯特空间时UCP(A,B(H))\mathrm{UCP}(\mathcal{A},B(\mathcal{H}))的C*-极点进行了完整分类。作为应用,我们对allall contractive skew-symmetric real matrices in Mn(R)M_n(\mathbb{R})中的所有C*-极点进行了分类。

关键词

引用

@article{arxiv.2502.15362,
  title  = {$C^*$-extreme points of unital completely positive maps on real $C^*$-algebras},
  author = {Anand O. R and K. Sumesh and Arindam Sutradhar},
  journal= {arXiv preprint arXiv:2502.15362},
  year   = {2025}
}

备注

A shorter proof of Theorem 3.18 is added. Proposition 4.3 and Lemma 4.4 are newly added. Modified the proof of Proposition 4.8. This work is accepted for publication in Studia Mathematica