AREA EXTREMAL PROBLEMS FOR NON-VANISHING FUNCTIONS

作者:Sheil Small T*
来源:Proceedings of the American Mathematical Society, 2011, 139(9): 3231-3245.
DOI:10.1090/S0002-9939-2011-11031-1

摘要

We consider the problem of finding the extremal function f which minimises the Bergman space A(2) norm for the class of non-vanishing functions whose first n+1 Taylor coefficients are given. We define an analytic function K in terms of f and show that the functions K and f satisfy a certain differential equation. This equation yields a set of relationships between the area moments and the circle moments of vertical bar f vertical bar(2), which in particular shows that the outer part of f is a polynomial of degree at most n.

  • 出版日期2011-9