5 papers · 1 filter
Half-integral Erdős-Pósa property for non-null - paths
Vera Chekan, Colin Geniet, Meike Hatzel +4
For a group , a -labelled graph is an undirected graph where every orientation of an edge is assigned an element of so that opposite orientations of the same edge are…
Adjacency posets of outerplanar graphs
Marcin Witkowski
Felsner, Li and Trotter showed that the dimension of the adjacency poset of an outerplanar graph is at most 5, and gave an example of an outerplanar graph whose adjacency poset has…
Counterexamples to Thomassen's conjecture on decomposition of cubic graphs
Thomas Bellitto, Tereza Klimošová, Martin Merker +2
We construct an infinite family of counterexamples to Thomassen's conjecture that the vertices of every 3-connected, cubic graph on at least 8 vertices can be colored blue and red…
Hamilton Cycles in Random Lifts of Graphs
Tomasz Łuczak, Łukasz Witkowski, Marcin Witkowski
For a graph the random -lift of is obtained by replacing each of its vertices by a set of vertices, and joining a pair of sets by a random matching whenever the corr…
Nonrepetitive sequences on arithmetic progressions
Jarosław Grytczuk, Jakub Kozik, Marcin Witkowski
A sequence is \emph{nonrepetitive} if no two adjacent blocks of are identical. In 1906 Thue proved that there exist arbitrarily long nonrepetitive sequenc…