Paired (n−1)-to-(n−1) disjoint path covers in bipartite transposition-like graphs

Abstract

A paired $k$-to-$k$ disjoint path cover of a graph $G$ is a collection of pairwise disjoint path subgraphs $P_1,P_2,\dots ,P_k$ such that each $P_i$ has prescribed vertices $s_i$ and $t_i$ as endpoints and the union of $P_1,P_2,\dots ,P_k$ contains all vertices of $G$. In this paper, we introduce bipartite transposition-like graphs, which are inductively constructed from lower ranked bipartite transposition-like graphs. We show that every rank $n$ bipartite transposition-like graph $G$ admit a paired $(n-1)$-to-$(n-1)$ disjoint path cover for all choices of $S=\{s_1,s_2,\dots ,s_{n-1}\}$ and $T=\{t_1,t_2,\dots ,t_{n-1}\}$, provided that $S$ is in one partite set of $G$ and $T$ is in the other.