论文标题
正同质对运算符
Orthonormal pairs of operators
论文作者
论文摘要
我们考虑成对的运算符$ a,b \ in B(h)$中,其中$ h $是hilbert空间,因此从$ \ {a,b \} $的跨度中存在线性等距$ f $,in $ \ {a,b \} $ in $ \ mathbb {c}^c}^2 $ mapping $ a,b $ b $ b $ in of OrthononMormal Vectors。我们证明了这种$ F $的存在,并确定通勤正常运营商中的所有这些对。然后,我们表征所有这些对$ a,b $(实际上,我们考虑一般集而不是对成对)的额外要求,即$ f $是完整的等值线,当$ h $带有列(或行)操作员空间结构时。我们还按照与正交范围的c $^*$ - 代数中的元素进行测量表征。
We consider pairs of operators $A,B\in B(H)$, where $H$ is a Hilbert space, such that there exist a linear isometry $f$ from the span of $\{A,B\}$ into $\mathbb{C}^2$ mapping $A,B$ into orthonormal vectors. We prove some necessary conditions for the existence of such an $f$ and determine all such pairs among commuting normal operators. Then we characterize all such pairs $A,B$ (in fact, we consider general sets instead of just pairs) under the additional requirement that $f$ is a complete isometry, when $H$ carries the column (or the row) operator space structure. We also metrically characterize elements in a C$^*$-algebra with orthogonal ranges.