English

Projective plane graphs and 3-rigidity

Combinatorics 2023-02-20 v2

Abstract

It is shown that a simple graph which is embeddable in the real projective plane is minimally 3-rigid if and only if it is (3,6)-tight. Moreover the topologically uncontractible embedded graphs of this type are constructible from one of 8 embedded graphs by a sequence of vertex splitting moves. In particular the characterisation of minimal 3-rigidity holds for a triangulated Mobius strip.

Keywords

Cite

@article{arxiv.2003.05514,
  title  = {Projective plane graphs and 3-rigidity},
  author = {Eleftherios Kastis and Stephen Power},
  journal= {arXiv preprint arXiv:2003.05514},
  year   = {2023}
}

Comments

34 pages (including a 9 page appendix). This is a substantial revision with fuller details and improved terminology. The main results are unchanged but there are new proofs and diagrams

R2 v1 2026-06-23T14:12:08.881Z