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arXiv · 2512.13585

On the transmission irregular trees with the maximum Wiener index

Ivan Damnjanović·Anran Xu·Kexiang Xu
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Abstract

The transmission of a vertex $v$ in a (chemical) graph $G$ is the sum of distances from $v$ to other vertices in $G$. If any two vertices of $G$ have different transmissions, then $G$ is transmission irregular. The Wiener index $W(G)$ of a graph $G$ is the sum of all distances between all unordered pairs of vertices in $G$, which has another formula as the half of the sum of transmissions of all vertices of $G$. In this paper, we consider the Wiener index maximization problem on the set of transmission irregular trees of a given order $n \in \mathbb{N}$. We solve the problem for all odd values of $n$ and for almost all even values of $n$. Each resolved extremal problem has a unique solution that is a chemical tree.

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Ivan Damnjanović, Anran Xu, Kexiang Xu. 2025-12-15. On the transmission irregular trees with the maximum Wiener index. https://doi.org/10.1007/s10878-025-01383-3

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