Ak. Tsikh, CONDITIONS FOR ABSOLUTE CONVERGENCE OF THE TAYLOR COEFFICIENT SERIES OF A MEROMORPHIC FUNCTION OF 2 VARIABLES, Mathematics of the USSR. Sbornik, 74(2), 1993, pp. 337-360
It is proved that the Taylor series of a meromorphic function of two v
ariables converges absolutely in the closed unit bidisk U2BAR if this
function satisfies a Holder condition in U2BAR with exponent 1/2, whil
e for any epsilon > 0 there exists a rational function with Holder exp
onent 1/2 - epsilon such that the indicated series diverges. This resu
lt solves the problem of stability of two-dimensional recursive digita
l filters. In its proof the structure of the asymptotic behavior of th
e Taylor coefficients of a meromorphic function of two variables is in
vestigated.