J. Ekstein

activity

20102025

most cited3-coloring triangle-free planar graphs with a precolored 9-cycle

5 citations · 5 across the 12 of their papers we have counts for

collaborators

Showing 2012Show all

3 papers · 1 filter

math.CO2012

Radio Labelings of Distance Graphs

R. Čada, J. Ekstein, P. Holub +1

A radio $k$ -labeling of a connected graph $G$ is an assignment $c$ of non negative integers to the vertices of $G$ such that $∣ c (x) - c (y) ∣ \geq k + 1 - d (x, y),$ for any two vertic…

math.CO2012

Hamiltonian Cycles in the Square of a Graph

Jan Ekstein

We show that under certain conditions the square of the graph obtained by identifying a vertex in two graphs with hamiltonian square is also hamiltonian. Using this result, we prov…

math.CO2012

Star subdivisions and connected even factors in the square of a graph

Jan Ekstein, Přemysl Holub, Tomáš Kaiser +2

For any positive integer $s$ , a $[2, 2 s]$ -factor in a graph $G$ is a connected even factor with maximum degree at most $2 s$ . We prove that if every induced $S (K_{1, 2 s + 1})$ in a gra…