Alexander Schrijver - CWI and University of Amsterdam

Open problems in combinatorial optimization

Abstract: We discuss some open problems given in my recent book "Combinatorial Optimization: Polyhedra and Efficiency". We plan to select from each of the eight parts of the book one problem, and give background and motivation.

Colloquium - 16:00

Alexander Bobenko - Technische Universität Berlin

Discrete Surfaces: Differential Geometry from Combinatorics

Abstract: Discrete differential geometry aims at the development of discrete equivalents of the geometric notions and methods of differential geometry. The latter appears then as a limit of refinements of the discretization. Discrete surfaces made from circles are discussed in the talk. We define some natural special classes (such as minimal) of those and show how they can be characterized by combinatorial data using new variational principles.