The $d$-dimensional realisation number of a rigid graph

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Authors: Sean Dewar, Anthony Nixon, Ben Smith
Cited by: 0

Abstract

Determining the number of (complex) realisations of a rigid graph for a specific choice of edge lengths is a fundamental problem in discrete geometry. In this article we provide two new tools for determining realisation numbers in arbitrary dimensions: (i) we prove that subgraph inclusion translates to realisation number divisibility; and (ii) we provide lower bounds on realisation numbers under specific graph operations in all dimensions. We use these methods to prove that every triangulated sphere with $n$ vertices has at least $2^{n-4}$ edge-length equivalent realisations in 3-dimensions, extending a 2-dimensional result of Jackson and Owen in the case of planar graphs. Additionally, our tools solve a family of conjectures set by Grasegger regarding how 1-extensions, X-replacements, and V-replacements affect realisation numbers.

Fields of Study & Subjects

Advanced Combinatorial Mathematics Computational Geometry and Mesh Generation Advanced Graph Theory Research

Publication details

Journal / source
arXiv (Cornell University)
Publication date
24 February 2026
Language
EN
Document type
Preprint