English

The lonely runner with seven runners

Combinatorics 2007-10-25 v1 Number Theory

Abstract

Suppose k+1k+1 runners having nonzero constant speeds run laps on a unit-length circular track starting at the same time and place. A runner is said to be lonely if she is at distance at least 1/(k+1)1/(k+1) along the track to every other runner. The lonely runner conjecture states that every runner gets lonely. The conjecture has been proved up to six runners (k5k\le 5). A formulation of the problem is related to the regular chromatic number of distance graphs. We use a new tool developed in this context to solve the first open case of the conjecture with seven runners.

Cite

@article{arxiv.0710.4495,
  title  = {The lonely runner with seven runners},
  author = {J. Barajas and O. Serra},
  journal= {arXiv preprint arXiv:0710.4495},
  year   = {2007}
}
R2 v1 2026-06-21T09:35:33.124Z