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Induced Forests in Regular Graphs with Large Girth

Published online by Cambridge University Press:  01 May 2008

CARLOS HOPPEN
Affiliation:
Department of Combinatorics and Optimization, University of Waterloo, Waterloo ON, CanadaN2L 3G1 (e-mail: choppen@math.uwaterloo.ca, nwormald@uwaterloo.ca)
NICHOLAS WORMALD
Affiliation:
Department of Combinatorics and Optimization, University of Waterloo, Waterloo ON, CanadaN2L 3G1 (e-mail: choppen@math.uwaterloo.ca, nwormald@uwaterloo.ca)

Abstract

An induced forest of a graph G is an acyclic induced subgraph of G. The present paper is devoted to the analysis of a simple randomized algorithm that grows an induced forest in a regular graph. The expected size of the forest it outputs provides a lower bound on the maximum number of vertices in an induced forest of G. When the girth is large and the degree is at least 4, our bound coincides with the best bound known to hold asymptotically almost surely for random regular graphs. This results in an alternative proof for the random case.

Type
Paper
Copyright
Copyright © Cambridge University Press 2008

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