EURO 2024 Copenhagen
Abstract Submission

EURO-Online login

3628. On the occurrence of optimally colored $K_{t,t}$ in canonical 1-factorizations of complete graphs

Invited abstract in session TA-25: Applications of combinatorial optimization I, stream Combinatorial Optimization.

Tuesday, 8:30-10:00
Room: 011 (building: 208)

Authors (first author is the speaker)

1. Sebastian Urrutia
University Molde
2. Dominique de Werra
IMA, EPFL

Abstract

Recoloring methods applied to optimally edge colored complete graphs of even size are fundamental components of local search procedures aiming to obtain 1-factorizations with specific properties. Then, there is an interest in finding in a 1-factorization, colored subgraphs that allow a local recoloring to obtain a new 1-factorization. The occurrence of bichromatic cycles, lanterns and optimally colored complete subgraphs in certain classes of 1-factorization has been previously studied. In this note we investigate the existence of optimally colored complete bipartite subgraphs in canonical 1-factorizations. We conclude that, whenever $n-1$ is a prime number, no optimally colored complete bipartite subgraphs with more than 4 nodes occur in canonical 1-factorizatoins of complete graphs with $n$ nodes. For other values of $n$ we show that optimally colored complete bipartite subgraphs with more than 4 nodes do occur and we show how to construct some of them. For some small bipartite subgraphs the construction given is proven to be unique.

Keywords

Status: accepted


Back to the list of papers