CP^2# n 上反近复结构的非存在性定理(英文)

Non-existence Theorem of Opposite Almost K■hler Structure on CP^2 # n ■~2

本文利用Seibery－Witten不变量，证明了：对于CP2#n2，n＝3，5和7，上任何Khler度量关于反近复结构不能成为近Khler度量。

In this short note, using Seiberg - Witten invariants, we prove that: any khler metric g on one of the surfaces CP2 # n CP2, for n = 3,5, and 7, cannot be almost khler with respect to the opposite almost complex structure. This problem was open in [2].