强次可加函数
Strongly subadditive functions
摘要：
设f是定义在正数上的函数。本文的主题是迹不等式$Tr f(A) + Tr f(P_2AP_2) \le Tr f(P_{12}AP_{12}) + \Tr f(P_{23}AP_{23})$，其中$A$是正算子，$P_1,P_2,P_3$是正交投影，使得$P_1+P_2+P_3=I$，$P_{12}=P_1+P_2$和$P_{23}=P_2+P_3$ .有几个函数f满足不等式（称为（SSA））的例子，并描述了等式的情况。
英文摘要：
Let f be a function defined on positive numbers. The subject is the trace inequality $Tr f(A) + Tr f(P_2AP_2) \le Tr f(P_{12}AP_{12}) + \Tr f(P_{23}AP_{23})$, where $A$ is a positive operator, $P_1,P_2,P_3$ are orthogonal projections such that $P_1+P_2+P_3=I$, $P_{12}=P_1+P_2$ and $P_{23}=P_2+P_3$. There are several examples of functions f satisfying the inequality (called (SSA)) and the case of equality is described.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
