摘要： Let H be a Hilbert space. and f(z) is an analytic function in unit disk,|f(z)|<1, then
||f'(A)|| ≤ (||I-f*(A)f(A)||(1)/2||I-f(A)f*(A)|(1)/2)/1-||A||2 where A is a proper contraction operator on H.
杨长森. A GENERALIZATION OF CARATHEODORY INERUALITY[J]. 数学物理学报(英文版), 1994, 14(2): 235-239.
Yang Chang-sen. A GENERALIZATION OF CARATHEODORY INERUALITY[J]. Acta mathematica scientia,Series B, 1994, 14(2): 235-239.