English

An Introduction to the Moebius Function

Combinatorics 2018-03-20 v1

Abstract

This is an introduction to the M\"obius function of a poset. The chief novelty is in the exposition. We show how order-preserving maps from one poset to another can be used to relate their M\"obius functions. We derive the basic results on the M\"obius function, applying them in particular to geometric lattices.

Keywords

Cite

@article{arxiv.1803.06664,
  title  = {An Introduction to the Moebius Function},
  author = {Chris Godsil},
  journal= {arXiv preprint arXiv:1803.06664},
  year   = {2018}
}

Comments

This is a slightly revised version of an old set of notes that have been available on my webpage for some time. The changes are not substantial. I've eliminated some old typos and introduced some ne ones (doubtless), and added one new section

R2 v1 2026-06-23T00:56:44.351Z