Published online by Cambridge University Press: 01 October 2008
Near exact Banach frames are introduced and studied, and examples demonstrating the existence of near exact Banach frames are given. Also, a sufficient condition for a Banach frame to be near exact is obtained. Further, we consider block perturbation of retro Banach frames, and prove that a block perturbation of a retro Banach frame is also a retro Banach frame. Finally, it is proved that if E and F are both Banach spaces having Banach frames, then the product space E×F has an exact Banach frame.
The research of the third author was supported by the Council of Scientific and Industrial Research (CSIR), India (vide letter no. 9/45(595)/2005-EMR-I dated 08.09.2005).