Title
A Complete Grammar for Decomposing a Family of Graphs into 3-connected Components
Abstract
Tutte has described in the book "Connectivity in graphs" a canonical decomposition of any graph into 3- connected components. In this article we translate using the language of symbolic combinatorics) Tutte's decomposition into a general grammar expressing any family G of graphs with some stability conditions) in terms of the subfamily G 3 of graphs in G that are 3- connected until now, such a general grammar was only known for the decomposition into 2- connected components). As a byproduct, our grammar yields an explicit system of equations to express the series counting a labelled) family of graphs in terms of the series counting the subfamily of 3-connected graphs. A key ingredient we use is an extension of the so-called dissymmetry theorem, which yields negative signs in the grammar and associated equation system, but has the considerable advantage of avoiding the difficult integration steps that appear with other approaches, in particular in recent work by Gimenez and Noy on counting planar graphs. As a main application we recover in a purely combinatorial way the analytic expression found by Gimenez and Noy for the series counting labelled planar graphs (such an expression is crucial to do asymptotic enumeration and to obtain limit laws of various parameters on random planar graphs). Besides the grammar, an important ingredient of our method is a recent bijective construction of planar maps by Bouttier, Di Francesco and Guitter. Finally, our grammar applies also to the case of unlabelled structures, since the dissymetry theorem takes symmetries into account. Even if there are still difficulties in counting unlabelled 3-connected planar graphs, we think that our grammar is a promising tool toward the asymptotic enumeration of unlabelled planar graphs, since it circumvents some difficult integral calculations.
Year
Venue
Keywords
2008
ELECTRONIC JOURNAL OF COMBINATORICS
connected component,planar graph,limit laws
Field
DocType
Volume
Discrete mathematics,Modular decomposition,Indifference graph,Combinatorics,Forbidden graph characterization,Robertson–Seymour theorem,Clique-sum,Chordal graph,Nowhere-zero flow,Pathwidth,Mathematics
Journal
15.0
Issue
ISSN
Citations 
1.0
1077-8926
15
PageRank 
References 
Authors
1.05
16
4
Name
Order
Citations
PageRank
Guillaume Chapuy17311.25
Eric Fusy2222.40
Mihyun Kang316329.18
Bilyana Shoilekova4151.05