BANACH JOURNAL OF MATHEMATICAL ANALYSIS, cilt.8, sa.2, ss.16-29, 2014 (SCI İndekslerine Giren Dergi)
Let C-A((n)) := C-A((n)) (D Chi D) denote the subspace of functions in the Banach space C-(n) (D Chi D) over bar which are analytic in the bi-disc D Chi D. We consider the subspace B-zw consisting from the functions f is an element of C-A((n)) which can be represented in the form f (z, w) = g (zw), where g is a single variable function from the disc algebra C-A (D). We prove that B-zw is a Banach algebra under the Duhamel multiplication