This is an announcement for the paper "A note on closedness of the sum of two closed subspaces in a Banach space" by Zhe-Ming Zheng and Hui-Sheng Ding.

Abstract: Let $X$ be a Banach space, and $M,N$ be two closed subspaces of $X$. We present several necessary and sufficient conditions for the closedness of $M+N$ ($M+N$ is not necessarily direct sum).

Archive classification: math.FA

Submitted from: dinghs@mail.ustc.edu.cn

The paper may be downloaded from the archive by web browser from URL

http://front.math.ucdavis.edu/1509.06445

or

http://arXiv.org/abs/1509.06445