The Friday Seminar is an informal weekly seminar for

• members of discrete mathematics group
• students in the group
• everybody else that is interested

Every week there is one speaker that gives a talk of one of the following kind

• presentation of original research
• introduction into an open problem that he/she currently works on
• presentation of proposed plan for bachelor, master, diploma or PhD thesis
• presentation of results from bachelor, master, diploma or PhD thesis
• presentation of research paper that might be of interest for the group

Friday July 25, 14:00

Kunal Dutta

For a finite set of points in the plane, a set in the plane, and a positive integer , we say that a -element subset of is captured by if there is a homothetic copy of such that , i.e., contains exactly elements from . A -uniform -capturing hypergraph has a vertex set and a hyperedge set consisting of all -element subsets of captured by .

We study the point-capturing hypergraphs formed when belongs to certain kinds of fat convex bodies. Using a result of Axenovich and Ueckerdt, we show that for large enough, is not only -colorable, but also has a nearly balanced -coloring.

• 2014/07/18 -- Jonathan Rollin -- Conflict-Free Colorings and Factors of Regular Graphs
• 2014/07/11 -- Georg Osang -- The Local Chromatic Number
• 2014/07/04 -- Andre Kündgen -- Spanning Quadrangulations of Triangulated Surfaces
• 2014/06/27 -- Sarah Lutteropp -- On Layered Drawings of Planar Graphs
• 2014/06/13 -- Jennifer Weidelich -- Adjacent Vertex Distinguishing Colorings
• 2014/06/06 -- Jonathan Klawitter -- Transforming Rectangles Into Squares
• 2014/05/30 -- Stefan Walzer -- Disjoint Induced Subgraphs of the Same Order and Size
• 2014/05/23 -- Pascal Weiner -- Improper Colourings of Graphs
• 2014/05/16 -- Open Discussion -- Sympossium Diskrete Mathematik 2014
• 2014/05/02 -- Peter Stumpf -- Covering Numbers of Different Kinds
• 2014/04/25 -- Anika Kaufmann -- Clumsy Packings of Regular Graphs Into a Complete Graph
• 2014/04/11 -- Piotr Micek -- Lower Bounds for On-Line Graph Colorings
• 2014/02/13 -- Yury Person -- Powers of Hamilton Cycles in Pseudorandom Graphs
• 2014/02/07 -- Sarah Lutteropp -- On Layered Drawings of Planar Graphs
• 2014/01/31 -- Stefan Walzer -- Tron : A Two Player Game on Graphs
• 2014/01/24 -- Annette Karrer -- Simultaneous Embeddings of Outerplanar Graphs
• 2014/01/17 -- Torsten Ueckerdt -- The Density of Fan-Planar Graphs
• 2014/01/10 -- Maria Axenovich -- On Distinguishing Colorings
• 2013/12/13 -- Fabian Stroh -- Coloring Graphs Using Topological Lemmas
• 2013/12/06 -- Enrica Cherubini -- Coloring Mixed Hypergraphs
• 2013/11/29 -- Jonathan Rollin -- Hamiltonicity in Sparse Graphs With High Chromatic Number
• 2013/11/18 -- Torsten Ueckerdt -- Scattered Sets in Cocomparability Graphs