English

Bounded diameter monochromatic component covers

Combinatorics 2026-01-07 v2

Abstract

Ryser conjectured that every rr-edge-coloured complete graph can be covered by r1r-1 monochromatic trees. Motivated by a question of Austin in analysis, Mili\'cevi\'c predicted something stronger -- that every rr-edge-coloured complete graph can be covered by r1r-1 monochromatic trees \emph{of bounded diameter}. Here we show that the two conjectures are equivalent. As immediate corollaries we obtain new results about Mili\'cevi\'c's Conjecture, most notably that it is true for r=5r=5. We also obtain several new cases of a generalization of Mili\'cevi\'c's Conjecture to non-complete graphs due to DeBiasio-Kamel-McCourt-Sheats.

Keywords

Cite

@article{arxiv.2507.05842,
  title  = {Bounded diameter monochromatic component covers},
  author = {Alexey Pokrovskiy},
  journal= {arXiv preprint arXiv:2507.05842},
  year   = {2026}
}
R2 v1 2026-07-01T03:51:07.940Z