中文

Schatten-von Neumann 范理想空间中 $\sigma$ -初等变换的扩展 Cauchy-Schwarz 不等式

泛函分析 2025-11-12 v1

摘要

q,r,s1q, r, s \geqslant 1 满足 12q+12r=1s\frac{1}{2q} + \frac{1}{2r} = \frac{1}{s}XCs(H)X \in \mathcal{C}_s(\mathcal{H})。若 (λn)n=1,(wn)n=1(\lambda_n)_{n=1}^{\infty}, (w_n)_{n=1}^{\infty}(0,+)(0,+\infty) 中的序列,且 (λn(1q)/(2q)An)n=1(\lambda_n^{(1-q)/(2q)} A_n)_{n=1}^{\infty}, (λn1/(2q)An)n=1(\lambda_n^{1/(2q)} A_n^*)_{n=1}^{\infty}, (wn1/(2r)Bn)n=1(w_n^{-1/(2r)} B_n)_{n=1}^{\infty}(wn(r1)/(2r)Bn)n=1(w_n^{(r-1)/(2r)} B_n^*)_{n=1}^{\infty} 均为强平方可和,则存在 \sidesetCs ⁣ ⁣n=1+AnXBn\sideset{^{_{{\scriptstyle\,\mathcal{C}}_{\large s}\!\!}}}{\phantom{}}{\textstyle\sum_{n=1}^{+\infty}}A_nXB_n,且\n\begin{equation*}\begin{split} &\bigg\|\!\sideset{^{_{{\scriptscriptstyle\,\Large\mathcal{C}_{\!s}\!\!}}}}{\phantom{}} \sum_{\,\,n=1}^{\,\,n=\infty}A_nXB_n\bigg\|_s \\ &\leqslant\bigg\|\!\sideset{^{_{{\scriptstyle\,{s}\!}}}}{\phantom{}}\sum_{\,n=1}^{\,\infty} \lambda_n^{\frac{1}{q}} A_n A_n^* \bigg\|^{\!\frac{1}{2} - \frac{1}{2q}}\! \bigg\|\!\sideset{^{_{{\scriptstyle\,{s}\!}}}}{\phantom{}}\sum_{\,n=1}^{\,\infty}w_n^{\!-\frac{1}{r}}\! B_n^* B_n \bigg\|^{\!\frac{1}{2} - \frac{1}{2r}}\! \bigg\|\!\bigg(\!\!\sideset{^{_{{\scriptstyle\,{s}\!}}}}{\phantom{}}\sum_{\,n=1}^{\,\infty} \lambda_n^{\!\frac{1}{q}-1}\! A_n^* A_n\! \bigg)^{\!\frac{1}{2q}}\! X\bigg(\!\!\sideset{^{_{{\scriptstyle\,{s}\!}}}}{\phantom{}}\sum_{\,n=1}^{\,\infty} w_n^{1-\frac{1}{r}}\! B_n B_n^*\! \bigg)^{\!\frac{1}{2r}}\! \bigg\|_s\!. \end{split} \end{equation*} 还给出等价不等式,并给出适用于 (λn)n=1(\lambda_n)_{n=1}^{\infty}(wn)n=1(w_n)_{n=1}^{\infty}B(H)\mathcal{B}(\mathcal{H}) 中但不为双强平方可和的序列 (An)n=1(A_n)_{n=1}^{\infty}(Bn)n=1(B_n)_{n=1}^{\infty} 的一些应用。本文所述结果显著扩展了关于 σ\sigma -初等变换在 Schatten-von Neumann 范理想空间中的先前作者的结果。

关键词

引用

@article{arxiv.2511.07613,
  title  = {Extended Cauchy-Schwarz inequalities for $\sigma$-elementary transformers in Schatten-von Neumann norm ideals},
  author = {Danko R. Jocić and Mihailo Krstić and Milan Lazarević and Stevan Milašinović},
  journal= {arXiv preprint arXiv:2511.07613},
  year   = {2025}
}