English

A refinement of Kelly's lemma for graph reconstruction for counting rooted subgraphs

Combinatorics 2023-12-29 v1

Abstract

Kelly's lemma is a basic result on graph reconstruction. It states that given the deck of a graph GG on nn vertices, and a graph FF on fewer than nn vertices, we can count the number of subgraphs of GG that are isomorphic to FF. Moreover, for a given card GvG-v in the deck, we can count the number of subgraphs of GG that are isomorphic to FF and that contain vv. We consider the problem of refining the lemma to count rooted subgraphs such that the root vertex coincides the deleted vertex. We show that such counting is not possible in general, but a multiset of rooted subgraphs of a fixed height kk can be counted if GG has radius more than kk. We also prove a similar result for the edge reconstruction problem.

Keywords

Cite

@article{arxiv.2312.17022,
  title  = {A refinement of Kelly's lemma for graph reconstruction for counting rooted subgraphs},
  author = {Deisiane Lopes Gonçalves and Bhalchandra D. Thatte},
  journal= {arXiv preprint arXiv:2312.17022},
  year   = {2023}
}

Comments

8 pages, 2 figures