Graph Reconstruction by Permutations

Pierre Ille1, William Kocay2
1Institut de Mathémathiques de Luminy CNRS — UMR 6206 163 avenue de Luminy, Case 907 13288 Marseille Cedex 9, France
2Computer Science Department St. Paul’s College, University of Manitoba Winninpeg, MB, Canada R3T 2N2

Abstract

Let \(G\) and \(H\) be graphs with a common vertex set \(V\), such that \(G – i \cong H – i\)for all \(i \in V\). Let \(p_i\) be the permutation of \(V – i\) that maps \(G – i\) to \(H – i\), and let \(q_i\) denote the permutation obtained from \(p_i\) by mapping \(i\) to \(i\). It is shown that certain algebraic relations involving the edges of \(G\) and the permutations \(q_iq_j^{-1}\) and \(q_iq_k^{-1}\), where \(i, j, k \in V\) are distinct vertices, often force \(G\) and \(H\) to be isomorphic.