The number and average size of connected sets in graphs with degree constraints

J Haslegrave - Journal of Graph Theory, 2022 - Wiley Online Library
The average size of connected vertex subsets of a connected graph generalises a much‐
studied parameter for subtrees of trees. For trees, the possible values of this parameter are …

The maximum number of connected sets in regular graphs

S Cambie, J Goedgebeur, J Jooken - arXiv preprint arXiv:2311.00075, 2023 - arxiv.org
We make some fundamental observations and conjectures on the number of connected sets
$ N (G) $ in $ d $-regular graphs $ G $. We improve the best known lower bounds on the …

A lower bound on the average size of a connected vertex set of a graph

A Vince - Journal of Combinatorial Theory, Series B, 2022 - Elsevier
The topic is the average order of a connected induced subgraph of a graph. This
generalizes, to graphs in general, the average order of a subtree of a tree. In 1983, Jamison …

The average size of a connected vertex set of a graph—explicit formulas and open problems

A Vince - Journal of Graph Theory, 2021 - Wiley Online Library
Although connectivity is a basic concept in graph theory, the enumeration of connected
subgraphs of a graph has only recently received attention. The topic of this paper is the …

[HTML][HTML] The path minimises the average size of a connected induced subgraph

J Haslegrave - Discrete Mathematics, 2022 - Elsevier
We prove that among connected graphs of order n, the path uniquely minimises the average
order of its connected induced subgraphs. This confirms a conjecture of Kroeker, Mol and …

The average order of a connected induced subgraph of a graph and union‐intersection systems

A Vince - Journal of Graph Theory, 2023 - Wiley Online Library
Because connectivity is such a basic concept in graph theory, extremal problems concerning
the average order of the connected induced subgraphs of a graph have been of notable …

On the Local and Global Mean Orders of Sub--Trees of -Trees

Z Luo, K Xu - The Electronic Journal of Combinatorics, 2023 - combinatorics.org
In this paper we show that for a given $ k $-tree $ T $ with a $ k $-clique $ C $, the local
mean order of all sub-$ k $-trees of $ T $ containing $ C $ is not less than the global mean …

The average size of a connected vertex set of a k-connected graph

A Vince - Discrete Mathematics, 2021 - Elsevier
The topic is the average order A (G) of a connected induced subgraph of a graph G. This
generalizes, to graphs in general, the average order of a subtree of a tree. In 1983 Jamison …

On the mean order of connected induced subgraphs of block graphs

KJ Balodis, ME Kroeker, L Mol… - arXiv preprint arXiv …, 2018 - arxiv.org
The average order of the connected induced subgraphs of a graph $ G $ is called the mean
connected induced subgraph (CIS) order of $ G $. This is an extension of the mean subtree …

A tight upper bound on the average order of dominating sets of a graph

I Beaton, B Cameron - Journal of Graph Theory, 2024 - Wiley Online Library
In this paper we study the average order of dominating sets in a graph, avd (G) \,avd\,(G).
Like other average graph parameters, the extremal graphs are of interest. Beaton and Brown …