A linear upper bound on the zero-sum Ramsey number of forests in $\mathbb{Z}_p$

TL;DR

This paper establishes a linear upper bound on the zero-sum Ramsey number for forests in the cyclic group rac{p}{} for prime p, relating the bound to the number of vertices and edges divisible by p.

Contribution

It provides the first linear upper bound on the zero-sum Ramsey number for forests in rac{p}{}, extending previous results to larger forests with specific divisibility conditions.

Findings

Zero-sum Ramsey number for forests is bounded linearly by vertices and prime p.

The bound applies to forests with at least 3p^2 - 12p + 11 vertices.

The result holds for forests with edges divisible by p, without isolated vertices.

Abstract

Let $m$ be a positive integer and let $G$ be a graph. The zero-sum Ramsey number $R(G,\mathbb{Z}_m)$ is the least integer $N$ (if it exists) such that for every edge-coloring $\chi \, : \, E(K_N) \, \rightarrow \, \mathbb{Z}_m$ one can find a copy of $G$ in $K_N$ such that $\sum_{e \, \in \, E(G)}{\chi(e)} \, = \, 0$. In this paper, we show that, for every prime $p$, $$R(F,\mathbb{Z}_p)\leq n+9p-12$$ for every forest $F$ in $n\geq 3p^2-12p+11$ vertices with $p\mid e(F)$ without isolated vertices.