查询词典 commutants

Although many results have been obtained, there are still a number of very interesting questions about composition operators unsolved. There is much more to be learned about the collective compactness and convergence of composition operator sequences, compactness of various product of composition operators, cyclicity, closed range and spectra of composition operators in various settings. Commutants of composition operators seem to be very difficult to characterize. Only a little is known about their reducing invariant subspaces. There has been no work on C〓 algebras generated by composition operators.

尽管已取得如此丰富的结果，但是关于复合算子仍然有大量非常有意义的问题值得研究，例如：复合算子序列的总体紧性及收敛性、复合算子的各种乘积的紧性、复合算子的闭值域问题、复合算子在各种解析函数空间上的谱的描述、换位复合算子的刻画、复合算子诱导的不变子空间问题、循环复合算子的研究、由复合算子生成的C〓-代数的研究、不同解析函数空间之间的加权复合算子及复合算子半群等等问题。

In recent years, K-theory has played an important role in studying the Operator Algebras. C. L. Jiang, J. S. Fang and Y. Cao find the connection between the uniquely strongly irreducible decomposition up to similarity of Type I operators and the K_0-groups of the commutants of the operators in 1990s.

近年来，K理论对算子代数与算子理论的发展起到了重要的推动作用。20世纪90年代，蒋春澜，房军生，曹阳等人发现了Ⅰ型算子的强不可约分解在相似意义下的唯一性与其换位代数的K_0群之间的内在联系。

Hanna: That's over now, isn't it?

都结束了，对吗

You must be ill. You look so pale.

你一定是病了，你的脸色苍白。