Published online by Cambridge University Press: 14 March 2011
We obtain necessary and sufficient conditions for the compactness of differences of composition operators acting on the weighted Bergman spaces in the unit ball. A representation of a composition operator as a finite sum of composition operators modulo compact operators is also studied.
The first author is supported by the Natural Science Foundation of Yunnan Province in China (Grant No. 2009ZC013X) and the Basic Research Foundation of the Education Bureau of Yunnan Province in China (Grant No. 09Y0079).