𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Homomorphism theorems for graphs

✍ Scribed by G. A. Dirac


Book ID
105167305
Publisher
Springer
Year
1964
Tongue
English
Weight
878 KB
Volume
153
Category
Article
ISSN
0025-5831

No coin nor oath required. For personal study only.


📜 SIMILAR VOLUMES


Homomorphism–homogeneous graphs
✍ Momchil Rusinov; Pascal Schweitzer 📂 Article 📅 2010 🏛 John Wiley and Sons 🌐 English ⚖ 141 KB

## Abstract We answer two open questions posed by Cameron and Nesetril concerning homomorphism–homogeneous graphs. In particular we show, by giving a characterization of these graphs, that extendability to monomorphism or to homomorphism leads to the same class of graphs when defining homomorphism–

Independence and graph homomorphisms gra
✍ Michael O. Albertson; Lily Chan; Ruth Haas 📂 Article 📅 1993 🏛 John Wiley and Sons 🌐 English ⚖ 305 KB

## Abstract A graph with __n__ vertices that contains no triangle and no 5‐cycle and minimum degree exceeding __n__/4 contains an independent set with at least (3__n__)/7 vertices. This is best possible. The proof proceeds by producing a homomorphism to the 7‐cycle and invoking the No Homomorphism

Extremal graphs for homomorphisms
✍ Jonathan Cutler; A. J. Radcliffe 📂 Article 📅 2011 🏛 John Wiley and Sons 🌐 English ⚖ 219 KB

The study of graph homomorphisms has a long and distinguished history, with applications in many areas of graph theory. There has been recent interest in counting homomorphisms, and in particular on the question of finding upper bounds for the number of homomorphisms from a graph G into a fixed imag

Homomorphism bounds for oriented planar
✍ T. H. Marshall 📂 Article 📅 2007 🏛 John Wiley and Sons 🌐 English ⚖ 202 KB

## Abstract If ${\cal C}$ is a class of oriented graphs (directed graphs without opposite arcs), then an oriented graph is a __homomorphism bound__ for ${\cal C}$ if there is a homomorphism from each graph in ${\cal C}$ to __H__. We find some necessary conditions for a graph to be a homomorphism bo