中文

量子Hellinger距离再探

数学物理 2020-07-29 v4 泛函分析 math.MP 量子物理

摘要

本短札旨在研究Bhatia等人近期考察的量子Hellinger距离[Lett. Math. Phys. 109 (2019), 1777-1804],特别关注重心问题。我们引入广义量子Hellinger散度族,其形式为ϕ(A,B)=Tr((1c)A+cBAσB)\phi(A,B)=\mathrm{Tr} \left((1-c)A + c B - A \sigma B \right),其中σ\sigma为任意Kubo-Ando平均,c(0,1)c \in (0,1)σ\sigma的权重。我们注意到这些散度属于极大量子ff-散度族,因此联合凸且满足数据处理不等式(DPI)。我们推导了这些广义量子Hellinger散度下有限个正定算子重心的刻画。我们注意到,上述Bhatia等人工作中所声称的重心即加权多元1/21/2-幂平均的刻画,在可交换算子情形下成立,但在一般情形下并不正确。

关键词

引用

@article{arxiv.1903.10455,
  title  = {Quantum Hellinger distances revisited},
  author = {József Pitrik and Dániel Virosztek},
  journal= {arXiv preprint arXiv:1903.10455},
  year   = {2020}
}

备注

v2: Section 4 on the commutative case, and Subsection 5.2 on a possible measure of non-commutativity added, as well as references to the maximal quantum $f$-divergence literature; v3: Section 4 on the commutative case improved, and the proposed measure of non-commutativiy changed accordingly; v4: accepted manuscript version