The maximum four point condition matrix of a tree
Abstract
The Four point condition (4PC henceforth) is a well known condition characterising distances in trees . Let be four vertices in and let denote the distance between vertices in . The 4PC condition says that among the three terms , and the maximum value equals the second maximum value. We define an sized matrix from a tree where the rows and columns are indexed by size-2 subsets. The entry of corresponding to the row indexed by and column is the maximum value among the three terms , and . In this work, we determine basic properties of this matrix like rank, give an algorithm that outputs a family of bases, and find the determinant of when restricted to our basis. We further determine the inertia and the Smith Normal Form (SNF) of .
Keywords
Cite
@article{arxiv.2308.08237,
title = {The maximum four point condition matrix of a tree},
author = {Ali Azimi and Rakesh Jana and Mukesh Kumar Nagar and Sivaramakrishnan Sivasubramanian},
journal= {arXiv preprint arXiv:2308.08237},
year = {2023}
}