English

Caterpillars with $n$ vertices are reconstructible from subgraphs with at most $n/2+1$ vertices

Combinatorics 2025-12-01 v1

Abstract

The \textit{m-deck} of an nn-vertex graph is the multiset of unlabeled induced subgraphs with mm vertices. Caterpillars are trees in which all nonleaf vertices lie on a single path. We prove for n48n\ge48 that any nn-vertex caterpillar is reconstructible (up to isomorphism) from its mm-deck when m>n/2m>n/2. The result is sharp, since for n6n\ge6 there are two nn-vertex caterpillars having the same n/2\lfloor n/2 \rfloor-deck. Our result proves the special case for caterpillars of a 1990 conjecture by N\'ydl about trees.

Keywords

Cite

@article{arxiv.2511.23309,
  title  = {Caterpillars with $n$ vertices are reconstructible from subgraphs with at most $n/2+1$ vertices},
  author = {Alexandr V. Kostochka and Zishen Qu and Maddy Ritter and Douglas B. West},
  journal= {arXiv preprint arXiv:2511.23309},
  year   = {2025}
}

Comments

60 pages, 4 figures