A generalization of heterochromatic graphs

Abstract

In 2006, Suzuki, and Akbari & Alipour independently presented a necessary and sufficient condition for edge-colored graphs to have a heterochromatic spanning tree, where a heterochromatic spanning tree is a spanning tree whose edges have distinct colors. In this paper, we propose $f$-chromatic graphs as a generalization of heterochromatic graphs. An edge-colored graph is $f$-chromatic if each color $c$ appears on at most $f(c)$ edges. We also present a necessary and sufficient condition for edge-colored graphs to have an $f$-chromatic spanning forest with exactly $m$ components. Moreover, using this criterion, we show that a $g$-chromatic graph $G$ of order $n$ with $|E(G)|>\left(\genfrac{}{}{0ex}{}{n-m}{2}\right)$ has an $f$-chromatic spanning forest with exactly $m$ ($1\le m\le n-1$) components if $g(c)\le \frac{|E(G)|}{n-m}f(c)$ for any color $c$.

arXiv comment14 pages, 4 figures

Cited by in corpus (1)

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