1 citations · 2 across the 12 of their papers we have counts for
25 papers
Coloring circle arrangements: New -chromatic planar graphs
Man-Kwun Chiu, Stefan Felsner, Manfred Scheucher +3
Felsner, Hurtado, Noy and Streinu (2000) conjectured that arrangement graphs of simple great-circle arrangements have chromatic number at most . Motivated by this conjecture, we…
Cycle lengths modulo in expanders
Anders Martinsson, Raphael Steiner
Given a constant , an -vertex graph is called an -expander if every set of at most vertices in has an external neighborhood of size at least . Addres…
Improved bound for improper colorings of graphs with no odd clique minor
Raphael Steiner
Strengthening Hadwiger's conjecture, Gerards and Seymour conjectured in 1995 that every graph with no odd -minor is properly -colorable, this is known as the Odd Hadwig…
Heroes in orientations of chordal graphs
Pierre Aboulker, Guillaume Aubian, Raphael Steiner
We characterize all digraphs such that orientations of chordal graphs with no induced copy of have bounded dichromatic number.
Disproof of a Conjecture by Woodall
Raphael Steiner
In 2001, Woodall conjectured that for every pair of integers , all graphs without a -minor are -choosable. In this note we refute this conjecture in a…
Improved lower bound for the list chromatic number of graphs with no minor
Raphael Steiner
Hadwiger's conjecture asserts that every graph without a -minor is -colorable. It is known that the exact version of Hadwiger's conjecture does not extend to list color…