English

A note on increasing paths in countable hypergraphs

Combinatorics 2022-12-06 v3 Discrete Mathematics

Abstract

An old result of M\"uller and R\"odl states that a countable graph GG has a subgraph whose vertices all have infinite degree if and only if for any vertex labeling of GG by positive integers, an infinite increasing path can be found. They asked whether an analogous equivalence holds for edge labelings, which Reiterman answered in the affirmative. Recently, Arman, Elliott, and R\"odl extended this problem to linear kk-uniform hypergraphs HH and generalized the original equivalence for vertex labelings. They asked whether Reiterman's result for edge labelings can similarly be extended. We confirm this for the case where HH admits only finitely many Berge cycles.

Keywords

Cite

@article{arxiv.2201.09794,
  title  = {A note on increasing paths in countable hypergraphs},
  author = {Valentino Vito},
  journal= {arXiv preprint arXiv:2201.09794},
  year   = {2022}
}

Comments

7 pages, 1 figure; minor revisions due to referee comments. Changed $\beta$-cycles to Berge cycles, a simpler and more well-known notion, with little impact on the main proof