Amending the Lonely Runner Spectrum Conjecture

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Authors: Ho Tin Fan, Alec Sun
Cited by: 1

Abstract

Let $\lVert x \rVert$ be the absolute distance from $x$ to the nearest integer. For a set of distinct positive integer speeds $v_1, \ldots, v_n$, we define its maximum loneliness, also known as the gap $\delta$, to be$$\text{ML}(v_1,\ldots,v_n) = \delta(v_1,\ldots,v_n) = \max_{t \in \mathbb{R}}\min_{1 \leq i \leq n} \lVert tv_i \rVert.$$The Loneliness Spectrum Conjecture, recently proposed by Kravitz, asserts that $$\exists s \in \mathbb{N}, \text{ML}(v_1,\ldots,v_n) = \frac{s} {sn + 1} \text{ or } \text{ML}(v_1,\ldots,v_n) \geq \frac{1}{n}.$$We disprove the Loneliness Spectrum Conjecture for $n = 4$ with an infinite family of counterexamples and propose an alternative conjecture. We confirm the amended conjecture for $n = 4$ whenever there exists a pair of speeds with a common factor of at least $3$ and prove some related results.

Fields of Study & Subjects

Limits and Structures in Graph Theory Graph Labeling and Dimension Problems

Publication details

Journal / source
The Electronic Journal of Combinatorics
Publisher
The Electronic Journal of Combinatorics
Volume
33
Issue
1
Publication date
26 February 2026
Language
EN