33 citations · 160 across the 17 of their papers we have counts for
9 papers · 1 filter
Covering lattice points by subspaces and counting point-hyperplane incidences
Martin Balko, Josef Cibulka, Pavel Valtr
Let and be integers with . Let be a -dimensional lattice and let be a -dimensional compact convex body symmetric about the origin. We provi…
Drawing graphs using a small number of obstacles
Martin Balko, Josef Cibulka, Pavel Valtr
An obstacle representation of a graph is a set of points in the plane representing the vertices of , together with a set of polygonal obstacles such that two vertices of …
Better upper bounds on the Füredi-Hajnal limits of permutations
Josef Cibulka, Jan Kynčl
A binary matrix is a matrix with entries from the set . We say that a binary matrix contains a binary matrix if can be obtained from by removal of some row…
On the Geometric Ramsey Number of Outerplanar Graphs
Josef Cibulka, Pu Gao, Marek Krčál +2
We prove polynomial upper bounds of geometric Ramsey numbers of pathwidth-2 outerplanar triangulations in both convex and general cases. We also prove that the geometric Ramsey num…
Ramsey numbers of ordered graphs
Martin Balko, Josef Cibulka, Karel Král +1
An ordered graph is a pair where is a graph and is a total ordering of its vertices. The ordered Ramsey number is th…
Maximum size of reverse-free sets of permutations
Josef Cibulka
Two words have a reverse if they have the same pair of distinct letters on the same pair of positions, but in reversed order. A set of words no two of which have a reverse is said…