Raphael Steiner

ETH Zürich
Dr. Raphael Steiner
Institut für Theoretische Informatik
CAB G 17
Universitätstrasse 6
8092 Zürich

Phone: +49 176 473 42551
E-Mail: raphaelmario.steiner@inf.ethz.ch

General Information

Since September 2021, I am an ETH Zurich Postdoctoral Fellow in the group of Prof. Angelika Steger. My research interests lie in combinatorics, in particular I am interested in graph minors, graph coloring, structural graph theory, directed graphs, extremal graph theory, discrete geometry, matroid theory and probabilistic methods applied to these areas. More information can be found on my personal webpage: LINK TO PERSONAL WEBPAGE

Here you can find my CV.

Preprints:

Subdigraphs of prescribed size and outdegree
Submitted

Inapproximability of shortest paths on perfect matching polytopes
(with J. Cardinal)
Submitted

Strengthening Hadwiger's conjecture for 4- and 5-chromatic graphs
(with A. Martinsson)
Submitted

Subdivisions with congruence constraints in digraphs of large chromatic number
Submitted

Exact matching: Correct parity and FPT parameterized by independence number
(with N. El Maalouly and L. Wulf)
Submitted

Coloring hypergraphs with excluded minors
Submitted

Hat guessing numbers of strongly degenerate graphs
(with C. Knierim and A. Martinsson)
Submitted

Tight bounds for divisible subdivisions
(with S. Das and N. Draganić)
Submitted

Journal articles:

J30. Coloring circle arrangements: New 4-chromatic planar graphs
(with M.-K. Chiu, S. Felsner, M. Scheucher, F. Schröder and B. Vogtenhuber)
European Journal of Combinatorics (accepted)

J29. Cycle lengths modulo k in expanders
(with A. Martinsson)
European Journal of Combinatorics, 2023

J28. Matching theory and Barnette's conjecture
(with M. Gorsky and S. Wiederrecht)
Discrete Mathematics, 2023

J27. On coloring digraphs with forbidden induced subgraphs
Journal of Graph Theory (accepted)

J26. Odd Hadwiger for line graphs
Discrete Mathematics, 2022

J25. Improved bound for improper colourings of graphs with no odd clique minor
Combinatorics, Probability and Computing, 2022

J24. Heroes in orientations of chordal graphs
(with P. Aboulker and G. Aubian)
SIAM Journal on Discrete Mathematics, 2022

J23. Disproof of a conjecture by Woodall
Electronic Journal of Combinatorics, 2022

J22. Improved lower bound for the list chromatic number of graphs with no K_t-minor
Combinatorics, Probability and Computing, 2022

J21. Asymptotic equivalence of Hadwiger's conjecture and its odd-minor variant
Journal of Combinatorial Theory, Series B, 2022

J20. Zero sum cycles in complete digraphs
(with T. Mészáros)
European Journal of Combinatorics, 2021

J19. Colorings of oriented planar graphs avoiding a monochromatic subgraph
(with H. Bergold and W. Hochstättler)
Discrete Applied Mathematics, 2022

J18. Complete directed minors and chromatic number
(with T. Mészáros)
Journal of Graph Theory, 2022

J17. Disjoint cycles with length constraints in digraphs of large connectivity or large minimum degree
SIAM Journal on Discrete Mathematics, 2022

J16. Even circuits in oriented matroids
(with K. Heuer and S. Wiederrecht)
Combinatorial Theory, 2022

J15. Oriented cycles in digraphs of large outdegree
(with L. Gishboliner and T. Szabó)
Combinatorica, 2022

J14. Dichromatic number and forced subdivisions
(with L. Gishboliner and T. Szabó)
Journal of Combinatorial Theory, Series B, 2022

J13. Coloring drawings of graphs
(with C. Hertrich and F. Schröder)
Electronic Journal of Combinatorics, 2022

J12. Topological drawings meet classical theorems from convex geometry
(with H. Bergold, S. Felsner, M. Scheucher and F. Schröder)
Discrete and Computational Geometry, 2022

J11. A note on coloring digraphs of large girth
Discrete Applied Mathematics, 2020

J10. On the average complexity of the k-level
(with M. Chiu, S. Felsner, M. Scheucher, P. Schnider and P. Valtr)
Journal of Computational Geometry, 2020

J9. Majority colorings of sparse digraphs
(with M. Anastos, A. Lamaison and T.Szabó)
Electronic Journal of Combinatorics, 2021

J8. A note on graphs of dichromatic number two
Discrete Mathematics and Theoretical Computer Science, 2021

J7. Complete acyclic colorings
(with S. Felsner, W. Hochstättler and K. Knauer)
Electronic Journal of Combinatorics, 2020

J6. Colouring non-even digraphs
(with M. G. Millani and S. Wiederrecht)
Electronic Journal of Combinatorics, 2022

J5. Flip distances between graph orientations
(with O. Aichholzer, J. Cardinal, T. Huynh, K. Knauer, T. Mütze and B. Vogtenhuber)
Algorithmica, 2021

J4. A note on universal point sets for planar graphs
(with M. Scheucher and H. Schrezenmaier)
Journal of Graph Algorithms and Applications, 2020

J3. On the complexity of digraph colourings and vertex arboricity
(with W. Hochstättler and F. Schröder)
Discrete Mathematics and Theoretical Computer Science, 2020

J2. The star dichromatic number
(with W. Hochstättler)
Discussiones Mathematicae Graph Theory, 2022

J1. Pentagon contact representations
(with S. Felsner and H. Schrezenmaier)
Electronic Journal of Combinatorics, 2018

Conference proceedings:

C11. Exact matching in graphs of bounded independence number
(with N. El Maalouly)
Symposium on Mathematical Foundations of Computer Science, MFCS 2022, 2022

C10. Edge partitions of complete geometric graphs
(with O. Aichholzer, J. Obenaus, J. Orthaber, R. Paul, P. Schnider, T. Taubner and B. Vogtenhuber)
Symposium on Computational Geometry, SoCG 2022, 2022

C9. Coloring circle arrangements: New 4-chromatic planar graphs
(with M.-K. Chiu, S. Felsner, M. Scheucher, F. Schröder and B. Vogtenhuber)
Proceedings EUROCOMB 2021, 2021

C8. Strongly Pfaffian graphs
(with M. Gorsky and S. Wiederrecht)
Proceedings EUROCOMB 2021, 2021

C7. Topological drawings meet classical theorems from convex geometry
(with H. Bergold, S. Felsner, M. Scheucher and F. Schröder)
Graph Drawing and Network Visualization, Proceedings Graph Drawing 2020, 2020

C6. Parametrized algorithms for directed modular width
(with Sebastian Wiederrecht)
Algorithms and Discrete Applied Mathematics, Proceedings CALDAM 2020, 2020

C5. Colouring non-even digraphs
(with M. G. Millani and Sebastian Wiederrecht)
Proceedings EUROCOMB 2019, 2019

C4. A note on universal point sets for planar graphs
(with M. Scheucher and H. Schrezenmaier)
Graph Drawing and Network Visualization, Proceedings GD 2019, 2019

C3. Flip distances between graph orientations
(with O. Aichholzer, J. Cardinal, T. Huynh, K. Knauer, T. Mütze and B. Vogtenhuber)
Graph Theoretical Concepts in Computer Science, Proceedings WG 2019, 2019

C2. Equiangular polygon contact representations
(with S. Felsner and H. Schrezenmaier)
Graph Theoretical Concepts in Computer Science, Proceedings WG 2018, 2018

C1. Pentagon contact representations
(with S. Felsner and H. Schrezenmaier)
Proceedings EUROCOMB 2017, 2017

Theses:

Cycle structure and colorings of directed graphs
PhD thesis, Technical University Berlin, 2021, under the supervision of Prof. Dr. Stefan Felsner

Neumann-Lara Flows and the Two Colour Conjecture
Master thesis, University of Hagen, 2018, under the supervision of Prof. Dr. Winfried Hochstättler

Existenz und Konstruktion von Dreieckszerlegungen triangulierter Graphen und Schnyder Woods
Bachelor thesis, University of Hagen, 2016, under the supervision of Prof. Dr. Winfried Hochstättler