30 citations · 34 across the 4 of their papers we have counts for
4 papers
On some power sum problems of Montgomery and Turan
Johan Andersson
We use an estimate for character sums over finite fields of Katz to solve open problems of Montgomery and Turan. Let h=>2 be an integer. We prove that inf_{|z_k| => 1} max_{v=1,...…
Lower bounds in some power sum problems
Johan Andersson
We study the power sum problem max_{v=1,...,m} | sum_{k=1}^n z_k^v | and by using features of Fejer kernels we give new lower bounds in the case of unimodular complex numbers z_k a…
Cross-shaped and Degenerate Singularities in an Unstable Elliptic Free Boundary Problem
J. Andersson, G. S. Weiss
We investigate singular and degenerate behavior of solutions of the unstable free boundary problem First, we construct a solution that is not of class $C^{1…
On the tangential touch between the free and the fixed boundaries for the two-phase obstacle-like problem
John Andersson, Norayr Matevosyan, Hayk Mikayelyan
In this paper we consider the following two-phase obstacle-problem-like equation in the unit half-ball . We prove that the free bou…