On approximately dual frames for Hilbert C * -modules


Ljiljana Arambašić




In this paper we discuss approximately dual frames for a frame or an outer frame of a Hilbert C *-module. We show that every frame or an outer frame, up to a scalar multiple, is approximately dual to itself. This enables us to get a canonical dual frame of a given frame (x n) n as a limit of approximately dual frames defined by (x n) n