Approximation with Respect to Sums of Chebyshev Norms. (Short Communications).
Let U be an open convex set in a Banach space E, F another Banach space. We consider the space HUb(U,F) of all F-valued holomorphic functions of bounded type in U possesing an asymptotic expansion in the origin. We study classes of asymptotic approximations such that two functions in the same class with an identical asymptotic expansion must coincide. In this paper, we characterize the functions belonging to some of these classes which are optimal approximations of a given series.