Global rigidity of unit ball graphs

Dániel Garamvölgyi, Tibor Jordán

Research output: Contribution to journalArticle


A d-dimensional bar-and-joint framework (G, p), where G is a graph and p maps the vertices of G to points in Rd, is said to be globally rigid if every d-dimensional framework (G, q) with the same graph and same edge lengths is congruent to (G, p). Global rigidity of frameworks and graphs is a well-studied area of rigidity theory with a number of applications, including the localization problem of sensor networks. Motivated by this application we consider the new notion of unit ball global rigidity, which can be defined similarly, except that (G, p) as well as (G, q) are required to be unit ball frameworks in the above definition. In a unit ball framework two vertices are adjacent if and only if their distance is less than a fixed constant (which corresponds to the sensing radius in a sensor network). In this paper we initiate a theoretical analysis of this version of global rigidity and prove several structural results. Among others we identify families of frameworks (and corresponding graphs G) in Rd for all d ≥ 1 which are unit ball globally rigid without being globally rigid in the usual sense. These families contain minimally rigid graphs, too, which have fewer edges than any of the globally rigid graphs on the same number of vertices.

Original languageEnglish
Pages (from-to)212-229
Number of pages18
JournalSIAM Journal on Discrete Mathematics
Issue number1
Publication statusPublished - Jan 1 2020



  • Global rigidity
  • Minimally rigid graph
  • Unit ball graph
  • Unit disk framework

ASJC Scopus subject areas

  • Mathematics(all)

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