a1 Department of Economics, University of California at Berkeley, Evans Hall, Berkeley, CA 94720, United States of America, e-mail: raimondo@econ.berkeley.edu
Abstract
We prove that if an operator A is a finite sum of finite products of Toeplitz operators on the Bergman space of the unit ball Bn, then A is compact if and only if its Berezin transform vanishes at the boundary. For n = 1 the result was obtained by Axler and Zheng in 1997.
(Received January 10 2000)