Webrelaunch 2020

AG Diskrete Mathematik (Winter Semester 2019/20)

The Thursday Seminar is an informal weekly seminar for

  • members of the discrete mathematics group,
  • students in the group,
  • and anyone else who is interested.

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

  • a presentation of original research
  • an introduction into an open problem that he/she currently works on
  • a presentation of proposed plan for bachelor, master, diploma or PhD thesis
  • a presentation of results from bachelor, master, diploma or PhD thesis
  • a presentation of a research paper that might be of interest to the group.
Schedule
Seminar: Thursday 14:00-15:30 SR 2.58

The seminar takes place in room SR 2.58 in the mathematics building 20.30.


Upcoming Talk

  • 2020/02/06 14:00 --Ryan Martin-- On difference graphs and the local dimension of posets


Talks: Winter Semester 2019

  • 2019/9/30 14:00 --Fabrizio Barbanera-- Covering numbers in Ramsey problems
  • 2019/10/17 14:00 --Richard Snyder-- Subdivisions of digraphs in tournaments
  • 2019/10/24 14:00 --Torsten Ueckerdt-- Plattenbauten: touching rectangles in space
  • 2019/10/31 14:00 --Sascha Stoll-- On subgraphs with minimum degree restrictions
  • 2019/11/07 14:00 --Stefan Ehard-- Blow-up lemmas: How to pack graphs
  • 2019/11/14 14:00 --Lea Weber-- The Erdos-Hajnal Conjecture in the bipartite setting
  • 2019/11/21 14:00 --Maria Axenovich-- Report from the workshop "Zero-Sum Ramsey Theory:

Graphs, Sequences and More"

  • 2019/11/27 15:45 --Jonathan Rollin-- Augmenting Geometric Graphs
  • 2019/12/05 14:00 --Richard Snyder-- Coloring graphs with no K_t minor
  • 2019/12/12 14:00 --Tamar Mirbach-- Multicolor Ramsey numbers
  • 2019/12/18 15:45 --Christian Ortlieb-- A theorem on c-strong colorings and minors in hypergraphs
  • 2020/01/09 14:00 --Maria Axenovich-- Induced Ramsey numbers for large stars versus a fixed graph
  • 2020/01/16 14:00 --Torsten Ueckerdt-- Height-2 posets with high girth, high average degree, but small dimension
  • 2020/01/23 14:00 --Ryan Martin-- Induced saturation in posets
  • 2020/01/30 14:00 --Paul Jungeblut-- Edge guarding plane graphs

Talk History

  • 2019/7/18 14:00 --Andre Kundgen-- Fractional graph coloring methods for degenerate graphs and graphs on surfaces
  • 2019/7/11 14:00 --Oscar Zamora-- Turan problems for planar graphs
  • 2019/7/4 14:00 --Jean-Sebastien Sereni-- Around the Petersen colouring conjecture
  • 2019/6/27 14:00 --Casey Tompkins-- Report on the Emlektabla workshop
  • 2019/6/13 14:00 --Maria Axenovich-- Report on Armenian workshop on Graphs, Combinatorics, Probability
  • 2019/6/6 14:00 --Tamar Mirbach-- Multicolor Turán Numbers
  • 2019/5/23 14:00 --Lasse Wulf-- Applications of Edge Coloring to Multiprocessor Communication
  • 2019/5/16 14:00 --Christian Ortlieb-- $c$-strong colorings of $t$-intersecting hypergraphs
  • 2019/5/9 14:00 --Sascha Stoll-- Full subgraphs by Victor Falgas-Ravry, Klas Markström, Jacques Verstraete
  • 2019/5/2 14:00 --Casey Tompkins-- The extremal number of Berge trees
  • 2019/4/25 14:00 --Casey Tompkins-- Extremal problems for Berge hypergraphs
  • 2019/1/24 14:00 -- Torsten Ueckerdt-- Local coverings of Young diagrams
  • 2019/1/17 14:00 -- David Offner-- Path and cycle decompositions of hypercubes
  • 2019/1/10 14:00 -- Maria Axenovich-- Clumsy packings of graphs
  • 2018/12/13 14:00 -- Nika Salia-- The structure of hypergraphs without long Berge cycles
  • 2018/12/6 14:00 -- Laurin Benz -- Complexity of induced arboricity in bipartite graphs
  • 2018/11/29 14:00 -- Tamar Mirbach -- On extremal-Ramsey function
  • 2018/11/22 14:00 -- Lea Weber -- The Erdos-Hajnal Conjecture
  • 2018/11/15 14:00 -- Annette Karrer -- The Contracting boundary of CAT(0)-groups
  • 2018/11/8 14:00 -- Casey Tompkins -- Generalised Turan Problems
  • 2018/25/18 14:00 -- David Offner -- Polychromatic colourings of hypercubes, complete graphs, and integers
  • 2018/10/18 14:00 -- Izolda Gorgol -- Two issues on induced Ramsey numbers
  • 2018/10/18 15:30 -- Dominik Dürrschnabel -- Distance Ramsey number
  • 2018/07/18-- Maximilian Müller -- Properties of 2K_2-free graphs
  • 2018/07/11-- Bundit Laekhanukit -- Geometric Representation of Graphs and Its Application to the Complexity of the Closest-Pair Problem
  • 2018/07/11-- Jonathan Noel -- Compactness of Graph and Hypergraph Limits via Entropy
  • 2018/06/27-- Lena Yuditsky -- Report from the 34th International Symposium on Computational Geometry (SoCG 2018)
  • 2018/06/20-- Torsten Ueckerdt -- Cover Decomposition for Bottomless Rectangles
  • 2018/06/13-- Maximilian Geißer -- Defective Colorings of K_{k,d}-minor-free Graphs
  • 2018/06/06-- Dominik Dürrschnabel -- Distance structure of graphs
  • 2018/05/23-- Christian Winter -- Extremal and Saturation Problems on Non-Uniform Hypergraphs
  • 2018/05/16-- Mónika Csikós -- Report from Colloquia in Combinatorics, London
  • 2018/05/02-- Torsten Ueckerdt -- A generalized Crossing Lemma
  • 2018/04/26 -- Jean-Sébastien Sereni -- On the number of 3-colourings of graphs
  • 2018/04/19 -- Mónika Csikós -- Variants of induced saturation of graphs
  • 2018/02/08 -- Oussama Bouaziz -- A closer look into signed graphs II
  • 2018/02/01 -- Maximilian Geißer -- Improper colorings of minorfree graphs
  • 2018/01/25 -- Lena Yuditsky -- The structure of almost all string graphs
  • 2018/01/18 -- Lena Yuditsky -- Report from Rio workshop on extremal and structural combinatorics
  • 2018/01/11 -- Maria Axenovich -- Induced Ramsey numbers for multiple copies of graphs
  • 2017/12/21 -- Frithjof Marquardt -- On the Chromatic Number of Graphs Forbidding Certain Induced Subgraphs
  • 2017/12/14 -- Nima Hoda -- Dismantlability, Invariant Cliques and Applications
  • 2017/12/07 -- Jonathan Rollin -- Report from 36'th Kolkom
  • 2017/11/30 -- Anika Kaufmann -- Clumsy Packings II
  • 2017/11/23 -- Torsten Ueckerdt -- On the maximum crossing number
  • 2017/11/17 -- Natasha Morrison -- Maximising the number of induced cycles in a graph
  • 2017/11/16 -- Viresh Patel -- Decomposing tournaments into paths
  • 2017/11/09 -- Mónika Csikós -- Strong Induced Saturation of Graphs
  • 2017/11/02 -- Jonathan Rollin -- Minimum Densities of Ramsey Graphs
  • 2017/10/27 -- Annette Karrer -- The universal cover of graphs with high chromatic number
  • 2017/10/26 -- Lena Yuditsky -- Andrew Suk's result for the Erdős-Szekeres problem
  • 2017/10/19 -- Lena Yuditsky -- Erdős-Szekeres without induction
  • 2017/07/28 -- Jonathan Rollin -- Hypergraph Containers and Random Graphs
  • 2017/07/21 -- Oussama Bouaziz -- A Closer Look into Signed Graphs
  • 2017/07/14 -- Peter Stumpf -- More on Different Graph Covering Numbers
  • 2017/07/07 -- Ursula Schade -- Planar Ramsey Graphs
  • 2017/06/30 -- Torsten Ueckerdt -- Induced and Weak Induced Arboricities
  • 2017/06/22 -- Ryan Martin -- The Saturation Number of Induced Subposets of the Boolean Lattice
  • 2017/06/16 -- Anika Kaufmann -- Clumsy Packings
  • 2017/06/09 -- Philip Dörr -- Induced Arboricity of Planar Graphs II
  • 2017/06/02 -- Peter Stumpf -- More on Different Graph Covering Numbers -- Structural, Extremal and Algorithmic Results
  • 2017/05/26 -- Rameez Ragheb -- Local Dimension of Posets
  • 2017/05/19 -- Torsten Ueckerdt -- The Queue Number of Posets
  • 2017/05/12 -- Robert Slomian -- Semi k-Colorable Graphs
  • 2017/05/05 -- Jonathan Rollin -- Extremal and Ramsey Type Questions for Ordered Graph
  • 2017/04/28 -- Mónika Csikós -- Induced Saturation of Graphs
  • 2017/03/10 -- Stefan Walzer -- Orientability of Random Hypergraphs
  • 2017/02/10 -- Christian Ortlieb -- Generalized Ramsey Numbers
  • 2017/02/03 -- Tamar Mirbach -- Ramsey Turnaround Numbers - A Variation of Online Ramsey Numbers
  • 2017/01/27 -- Yen Hoang Le -- Minimum Saturated Graphs
  • 2017/01/20 -- Robert Slomian -- Graphs without 4-Chromatic Ivies
  • 2017/01/13 -- Jonathan Rollin -- Ramsey Theory for Ordered Graphs
  • 2016/12/16 -- Philip Dörr -- Induced Arboricity on Planar Graphs
  • 2016/12/09 -- Mónika Csikós -- \epsilon-nets and k-union VC dimension
  • 2016/12/02 -- Christian Kouekam -- On Ordered Ramsey Numbers
  • 2016/11/18 -- Maria Axenovich -- Improper Colorings of Planar Graphs
  • 2016/11/11 -- Dominik Dürrschnabel -- Disjoint Homometric Sets in Graphs
  • 2016/11/04 -- Lasse Wulf -- Stacked Treewidth and the Colin de Verdiére Number
  • 2016/10/28 -- Peter Stumpf -- More on Different Graph Covering Numbers
  • 2016/10/21 -- Torsten Ueckerdt -- Inclusion Orders in the Plane
  • 2016/07/22 -- Fabian Stroh -- How To Share Trees Optimally
  • 2016/07/08 -- Torsten Ueckerdt -- Unit Distances in a Convex Polygon
  • 2016/07/01 -- Jonathan Klawitter -- Combinatorial Aspects of Contact Graphs
  • 2016/06/24 -- Dominik Dürrschnabel -- Disjoint Homometric Sets in Graphs
  • 2016/06/17 -- Sascha Stoll -- On Conflict-Free Colorings of Planar Graphs
  • 2016/06/10 -- Torsten Ueckerdt -- A Beginner's Guide to Tree-Width
  • 2016/06/03 -- Agnes Grünewald -- On the Induced Ramsey Number
  • 2016/05/27 -- Lasse Wulf -- An Introduction to the Colin de Verdière Number of a Graph
  • 2016/05/20 -- Jonathan Rollin -- The k-Strong Induced Arboricity of Tree-Depth d Graphs
  • 2016/05/13 -- Torsten Ueckerdt -- The Induced Arboricity of a Graph
  • 2016/05/06 -- Annette Karrer -- Non-Colorable Uniform Bihypergraphs with High Girth
  • 2016/04/29 -- Hanno Lefmann -- Edge Colorings of Graphs Without Fixed Colored Subgraphs
  • 2016/04/22 -- Pacsal Schmitt -- Disjoint Induced Subgraphs of the Same Order and Size
  • 2016/03/15 -- Daniel Goncalves -- Entropy Compression Method Applied to Graph Coloring
  • 2016/02/12 -- Jonathan Rollin -- Conflicts in Ordered Graphs
  • 2016/02/05 -- Torsten Ueckerdt -- Blossoming Trees and Planar Graphs
  • 2016/01/29 -- Yassine Marrakchi -- Approximation Scheme for Maximum Independent Set of Rectangles
  • 2016/01/22 -- Maria Axenovich -- Transversal Families for Edge-colored Complete Graphs
  • 2016/01/15 -- Gregor Lagodzinski -- Combinatorics of 2-connected Series-parallel Graphs
  • 2015/12/18 -- Torsten Ueckerdt -- Schnyder's Theorem -- continued
  • 2015/12/11 -- Fabian Stroh -- Sharing Even Spiders
  • 2015/12/04 -- Jonathan Rollin -- Ramsey Multiplicities
  • 2015/11/27 -- Torsten Ueckerdt -- The Interval Number of Planar Graphs
  • 2015/11/20 -- Annette Karrer -- Uncolorable Bihypergraphs with Few Edges
  • 2015/11/13 -- Julia Heller -- Noncrossing Partitions in Geometric Group Theory
  • 2015/11/06 -- Jonathan Rollin -- The Chromatic Number of Ordered Graphs
  • 2015/10/30 -- Kolja Knauer -- Drawing Graphs with Vertices and Edges in Convex Position
  • 2015/10/23 -- Torsten Ueckerdt -- Schnyder's Theorem
  • 2015/09/11 -- Mujiangshan Wang -- The 1-Good-Neighbor Diagnosability of Cayley Graphs Generated by Transposition Trees under the PMC Model and MM∗ Model
  • 2015/07/17 -- Maria Axenovich -- Report from Ron Graham's Birthday Conference
  • 2015/07/10 -- Stefan Walzer -- Finding Monochromatic Cubes in Coloured Cubes
  • 2015/07/03 -- Jonathan Rollin -- Degrees and Factors in Graphs
  • 2015/06/26 -- Stefan Walzer -- Secure Card-Based Computation
  • 2015/06/19 -- Jonathan Klawitter -- Crossing Minimisation in Book Embeddings
  • 2015/06/12 -- Stephen G. Kobourov -- 1-Planar Graphs
  • 2015/06/05 -- Maria Axenovich -- Hales-Jewett Theorem and Ramsey Classes
  • 2015/05/29 -- Peter Stumpf -- On Covering Numbers of Different Kinds
  • 2015/05/22 -- Sebastian Ziesche -- A Short Introduction to Percolation
  • 2015/05/15 -- Torsten Ueckerdt -- The Etiquette of Sharing a Cake
  • 2015/05/08 -- Alexander Koch and Stefan Walzer -- TikZ vs. Ipe
  • 2015/04/24 -- Felix Joos -- An Approximation of the Packing-Covering Duality
  • 2015/04/17 -- Torsten Ueckerdt -- Combinatorial Graph Sharing Games
  • 2015/02/06 -- Stefan Walzer -- 2-Dimension and Ramsey Lattices
  • 2015/01/30 -- Maria Axenovich -- Size Anti-Ramsey Numbers
  • 2015/01/23 -- Jonathan Rollin -- Ramsey Equivalent Graphs
  • 2015/01/16 -- Torsten Ueckerdt -- Contact Representations of Sparse Planar Graphs
  • 2015/01/09 -- Dirk Tröndle -- Convex Distance Function Delaunay Triangulations
  • 2014/12/19 -- Valentin Braun -- On-line Graph Colorings
  • 2014/12/12 -- Anika Kaufmann -- On Clumsy Packing of Complete Graphs
  • 2014/12/05 -- Jennifer Weidelich -- Adjacent Vertex Distinguishing Colorings of Bipartite Graphs
  • 2014/11/28 -- Pascal Weiner -- H-free Colourings of Planar Graphs
  • 2014/11/21 -- Stefan Walzer -- On the Size of Sumsets
  • 2014/11/14 -- Jonathan Klawitter -- Transforming Rectangles Into Squares
  • 2014/10/31 -- Jonathan Rollin -- Brooks Type Results for Conflict-Free Colorings and \{a,b\}-Factors
  • 2014/10/24 -- Torsten Ueckerdt -- Online Coloring Between Two Lines
  • 2014/07/25 -- Kunal Dutta -- On the Discrepancy of Certain Point-Capturing Hypergraphs
  • 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
  • 2013/12/20 -- Dirk Tröndle -- Convex Distance Funtion Delaunay Triangulations
  • 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
  • 2013/07/19 -- André Kündgen -- Central digraphs
  • 2013/02/12 -- Maria Axenovich -- On Ramsey Numbers and Size Ramsey Numbers
  • 2013/02/05 -- Torsten Ueckerdt and Maria Axenovich -- Non-crossing Connectors in the Plane and Twins
  • 2013/01/29 -- Maria Axenovich -- On a Reconstruction Problem for Sequences
  • 2013/01/22 -- Torsten Ueckerdt -- Combinatorial and Geometric Properties of Planar Laman Graphs
  • 2013/01/15 -- Jonathan Rollin -- Unique Edge Colorings
  • 2012/12/18 -- Fabian Stroh -- Coloring Kneser Graphs
  • 2012/12/11 -- Ignaz Rutter -- Research on Stack- and Queue-number of Graphs
  • 2012/12/04 -- Torsten Ueckerdt -- Research on Coloring Geometric Hypergraphs
  • 2012/11/27 -- Alexander Koch -- Representations of Graphs by Outside Obstacles
  • 2012/11/20 -- Daniel Hoske -- Book Embedding with Fixed Page Assignments
  • 2012/11/13 -- Maria Axenovich -- On Bar-Visibility Representations of Graphs
  • 2012/11/06 -- Judith Stumpp -- Online Size Anti-Ramsey Numbers
  • 2012/10/30 -- Stefan Walzer -- Clumsy Packings - Wasting Space in Geometric Puzzles
  • 2012/10/23 -- Jonathan Rollin -- Report from 4 PCC, Poznan
  • 2012/10/16 -- Torsten Ueckerdt -- The Twin Problem