Connectivity for random graphs from a weighted bridge-addable class

Colin McDiarmid¹

¹University of Oxford, UK

The electronic journal of combinatorics, Tome 19 (2012) no. 4

Résumé

There has been much recent interest in random graphs sampled uniformly from the $n$-vertex graphs in a suitable structured class, such as the class of all planar graphs. Here we consider a general bridge-addable class $\cal A$ of graphs -- if a graph is in $\cal A$ and $u$ and $v$ are vertices in different components then the graph obtained by adding an edge (bridge) between $u$ and $v$ must also be in $\cal A$. Various bounds are known concerning the probability of a random graph from such a class being connected or having many components, sometimes under the additional assumption that bridges can be deleted as well as added. Here we improve or amplify or generalise these bounds (though we do not resolve the main conjecture). For example, we see that the expected number of vertices left when we remove a largest component is less than 2. The generalisation is to consider `weighted' random graphs, sampled from a suitable more general distribution, where the focus is on the bridges.

Détail

DOI : 10.37236/2596

Classification : 05C80, 05C40
Mots-clés : random graph, connectivity, components, b ridge-addable class