scholarly journals Notes on weak-odd edge colorings of digraphs

Author(s):  
César Hernández-Cruz ◽  
Mirko Petruševski ◽  
Riste Škrekovski
Keyword(s):  
2021 ◽  
Vol 344 (4) ◽  
pp. 112309
Author(s):  
Fiachra Knox ◽  
Bojan Mohar ◽  
Nathan Singer
Keyword(s):  

2012 ◽  
Vol 312 (8) ◽  
pp. 1393-1399 ◽  
Author(s):  
R.R. Kamalian ◽  
P.A. Petrosyan

2011 ◽  
Vol 159 (7) ◽  
pp. 595-604
Author(s):  
Robert E. Jamison
Keyword(s):  

10.37236/2102 ◽  
2012 ◽  
Vol 19 (1) ◽  
Author(s):  
Geoffrey Exoo

The lower bound for the classical Ramsey number $R(4,6)$ is improved from 35 to 36. The author has found 37 new edge colorings of $K_{35}$ that have no complete graphs of order 4 in the first color, and no complete graphs of order 6 in the second color. The most symmetric of the colorings has an automorphism group of order 4, with one fixed point, and is presented in detail. The colorings were found using a heuristic search procedure.


2008 ◽  
Vol Vol. 10 no. 3 (Graph and Algorithms) ◽  
Author(s):  
Dariusz Dereniowski ◽  
Adam Nadolski

Graphs and Algorithms International audience We study two variants of edge-coloring of edge-weighted graphs, namely compact edge-coloring and circular compact edge-coloring. First, we discuss relations between these two coloring models. We prove that every outerplanar bipartite graph admits a compact edge-coloring and that the decision problem of the existence of compact circular edge-coloring is NP-complete in general. Then we provide a polynomial time 1:5-approximation algorithm and pseudo-polynomial exact algorithm for compact circular coloring of odd cycles and prove that it is NP-hard to optimally color these graphs. Finally, we prove that if a path P2 is joined by an edge to an odd cycle then the problem of the existence of a compact circular coloring becomes NP-complete.


2016 ◽  
Vol 36 (3) ◽  
pp. 709 ◽  
Author(s):  
Arnfried Kemnitz ◽  
Massimiliano Marangio ◽  
Margrit Voigt
Keyword(s):  

2010 ◽  
Vol 1 (4) ◽  
pp. 441-475 ◽  
Author(s):  
Hanno Lefmann ◽  
Yury Person ◽  
Mathias Schacht

Sign in / Sign up

Export Citation Format

Share Document