Events

Title: Graphs of Homomorphisms

Abstract: If X and Y are graphs and f is a function on V (X) taking values in V (Y ), then the graph of
f is the subset formed by the pairs (x; f(x)) for x in V (X).

Title: Extending Thomassen’s Theorem to Two Faces

Abstract:

Let G be a planar graph and let L be a list-assignment for G in which there is a precolored edge on the outer face, every other vertex on the outer face has a list of size at least 3, and every other vertex in G has a list of size at least 5.

Title: Primal-dual and Lagrangian relaxation techniques for k-median

Abstract: We will develop primal-dual algorithms to obtain constant-factor approximations for the uncapacitated facility location problem.

Title: New algorithms for maximum disjoint paths based on tree-likeness

Abstract:

We study the classical NP-hard problems of finding maximum-size subsets from given sets of k terminal pairs that can be routed via edge-disjoint paths (MaxEDP) or node-disjoint paths (MaxNDP) in a given graph.

Title: Maximum Independent Sets in Erdos-Ko-Rado Combinatorics

Abstract:  We discuss a general algebraic method for characterizing maximum independent sets in graphs that arise in Erdos-Ko-Rado combinatorics, provided the graphs are large enough. 

Title: Some problems on the size Ramsey numbers

Abstract: For given simple graphs $G_1$ and $G_2$, the size Ramsey number $\hat{R}(G_1,G_2)$ is the smallest positive integer $m$,

Title:Local Search Guarantees on Facility Location Problems

Abstract: We will show that guarantees can be given on algorithms for the k-median problem based on local search heuristics.

Title: Vertex Minors

Abstract:

I will give an introduction to vertex-minors of graphs. At first sight vertex minors are a bit peculiar but they are closely related to graph minors and possibly even easier to work with.

Title: Approximating k-Median via Pseudo-Approximation

Abstract: In the last two talks we saw two approaches for approximating k-median.

Title: Razborov's flag algebras: Ten years on

Abstract:

Many of the classical results in extremal combinatorics were obtained by ingenious application of elementary techniques, such as induction and Cauchy-Schwarz inequality.