5 papers
An improved upper bound for the planar Turán number of
Xuqing Bai, Weichan Liu, Xiangxiang Nie +1
We prove that every -vertex simple planar graph with no copy of has at most \[ \frac{69}{25}(n-2) \] edges, for every . This improves the best known bound \[ \frac…
Upper bounds on the running time of bootstrap percolation
Weichan Liu, Xiangxiang Nie, Simón Piga +1
For -graphs and the -bootstrap percolation process (or -process) starting with is a sequence of -graphs such that is obtained…
Transversal tilings in k-partite graphs without large holes
Xinyu He, Xiangxiang Nie, Donglei Yang
We show that for any constant and , there exists such that the following holds for sufficiently large . If is a spa…
Covering graphs by isometric trees
Paul Bastide, Julien Duron, Jędrzej Hodor +2
A connected subgraph of a graph is isometric if it preserves distances. Recently, graphs admitting a vertex or edge covering by a small number of isometric paths have been studied.…
Perfect tilings with the generalised triangle in -graphs
Weichan Liu, Xiangxiang Nie, Donglei Yang +1
Denote by the generalised triangle, a -uniform hypergraph on vertex set with three edges , and $\{k,k+1,\dots,…