Sergey Zelik visited the  Istanbul Center for Mathematical Sciences for a few weeks in July and August.  The center is associated with Bogazici University in Turkey.  While there he gave a talk on Friday 2nd August on “Green functions and sharp point-wise interpolation inequalities”.  An abstract of the talk follows: a general method of finding sharp constants in interpolation inequalities on manifolds involving the Hilbertian and C-norms was presented. The method is strongly based on the properties of Green functions for the associated elliptic problems and especially on their asymptotic behavior when the spectral parameter tends to infinity. A number of examples including inequalities on spheres, tori and some manifolds with boundary were also discussed.