Special Functions Commons^™

Interpolating With Outer Functions, Javad Mashreghi, Marek Ptak, William T. Ross

Department of Math & Statistics Faculty Publications

The classical theorems of Mittag-Leffler and Weierstrass show that when (λn)n≥1 is

a sequence of distinct points in the open unit disk D, with no accumulation points in

D, and (wn)n≥1 is any sequence of complex numbers, there is an analytic function

ϕ on D for which ϕ(λn) = wn. A celebrated theorem of Carleson [2] characterizes

when, for a bounded sequence (wn)n≥1, this interpolating problem can be solved with

a bounded analytic function. A theorem of Earl [5] goes further and shows that when

Carleson’s condition is satisfied, the interpolating function ϕ can be …