English
Related papers

Related papers: Frameworks with forced symmetry I: Reflections and…

200 papers

A result due in its various parts to Hendrickson, Connelly, and Jackson and Jord\'an, provides a purely combinatorial characterisation of global rigidity for generic bar-joint frameworks in $\mathbb{R}^2$. The analogous conditions are known…

Metric Geometry · Mathematics 2013-06-12 Bill Jackson , Thomas McCourt , Anthony Nixon

A bar-joint framework $(G,p)$ is the combination of a finite simple graph $G=(V,E)$ and a placement $p:V\rightarrow \mathbb{R}^d$. The framework is rigid if the only edge-length preserving continuous deformations of the vertices arise from…

Combinatorics · Mathematics 2023-12-18 Anthony Nixon , Bernd Schulze , Joseph Wall

In this paper, we introduce a natural classification of bar and joint frameworks that possess symmetry. This classification establishes the mathematical foundation for extending a variety of results in rigidity, as well as infinitesimal or…

Metric Geometry · Mathematics 2008-08-14 Bernd Schulze

A linearly constrained framework in $\mathbb{R}^d$ is a point configuration together with a system of constraints which fixes the distances between some pairs of points and additionally restricts some of the points to lie in given affine…

Combinatorics · Mathematics 2022-12-09 Hakan Guler , Bill Jackson , Anthony Nixon

Combinatorial rigidity theory seeks to describe the rigidity or flexibility of bar-joint frameworks in R^d in terms of the structure of the underlying graph G. The goal of this article is to broaden the foundations of combinatorial rigidity…

Combinatorics · Mathematics 2011-10-05 Mike Develin , Jeremy L. Martin , Victor Reiner

We show that a generic framework $(G,p)$ on the cylinder is globally rigid if and only if $G$ is a complete graph on at most four vertices or $G$ is both redundantly rigid and $2$-connected. To prove the theorem we also derive a new…

Combinatorics · Mathematics 2018-10-16 Bill Jackson , Anthony Nixon

A bar-joint framework $(G,p)$ is the combination of a finite simple graph $G=(V,E)$ and a placement $p:V\rightarrow \mathbb{R}^d$. The framework is rigid if the only edge-length preserving continuous motions of the vertices arise from…

Combinatorics · Mathematics 2023-12-20 Anthony Nixon , Bernd Schulze , Joseph Wall

A framework (a straight-line embedding of a graph into a normed space allowing edges to cross) is globally rigid if any other framework with the same edge lengths with respect to the chosen norm is an isometric copy. We investigate global…

Metric Geometry · Mathematics 2025-04-04 Sean Dewar

Symmetry equations are obtained for the rigidity matrix of a bar-joint framework in R^d. These form the basis for a short proof of the Fowler-Guest symmetry group generalisation of the Calladine-Maxwell counting rules. Similar symmetry…

Metric Geometry · Mathematics 2010-09-23 J. C. Owen , S. C. Power

Sparse graphs and their associated matroids play an important role in rigidity theory, where they capture the combinatorics of generically rigid structures. We define a new family called {\bf graded sparse graphs}, arising from generically…

Combinatorics · Mathematics 2011-11-10 Audrey Lee , Ileana Streinu , Louis Theran

A number of recent papers have studied when symmetry causes frameworks on a graph to become infinitesimally flexible, or stressed, and when it has no impact. A number of other recent papers have studied special classes of frameworks on…

Metric Geometry · Mathematics 2010-06-07 Bernd Schulze , Walter Whiteley

In 1992, Hendrickson proved that (d+1)-connectivity and redundant rigidity are necessary conditions for a generic (non-complete) bar-joint framework to be globally rigid in $\mathbb{R}^d$. Jackson and Jordan confirmed in 2005 that these…

Combinatorics · Mathematics 2019-09-17 Viktoria E. Kaszanitzky , Bernd Schulze , Shin-ichi Tanigawa

We develop a rigidity theory for frameworks in $\mathbb{R}^3$ which have two coincident points but are otherwise generic and only infinitesimal motions which are tangential to a family of cylinders induced by the realisation are considered.…

Combinatorics · Mathematics 2016-07-08 Bill Jackson , Viktoria Kaszanitzky , Anthony Nixon

In this paper we prove a recursive characterisation of generic rigidity for frameworks periodic with respect to a partially variable lattice. We follow the approach of modelling periodic frameworks as frameworks on a torus and use the…

Combinatorics · Mathematics 2012-04-09 Anthony Nixon , Elissa Ross

We present a survey of results concerning the use of inductive constructions to study the rigidity of frameworks. By inductive constructions we mean simple graph moves which can be shown to preserve the rigidity of the corresponding…

Metric Geometry · Mathematics 2013-06-18 Anthony Nixon , Elissa Ross

We give an algebraic characterization of when a $d$-dimensional periodic framework has no non-trivial, symmetry preserving, motion for any choice of periodicity lattice. Our condition is decidable, and we provide a simple algorithm that…

Metric Geometry · Mathematics 2015-03-10 Justin Malestein , Louis Theran

Periodic frameworks with crystallographic symmetry are investigated from the perspective of a general deformation theory of periodic bar-and-joint structures in $R^d$. It is shown that natural parametrizations provide affine section…

Metric Geometry · Mathematics 2011-10-24 Ciprian S. Borcea , Ileana Streinu

In structural rigidity, one studies frameworks of bars and joints in Euclidean space. Such a framework is an articulated structure consisting of rigid bars, joined together at joints around which the bars may rotate. In this paper, we will…

Combinatorics · Mathematics 2024-08-28 Joannes Vermant , Klara Stokes

This paper studies the properties of two kinds of matroids: (a) algebraic matroids and (b) finite and infinite matroids whose ground set have some canonical symmetry, for example row and column symmetry and transposition symmetry. For (a)…

Combinatorics · Mathematics 2013-12-16 Franz J. Király , Zvi Rosen , Louis Theran

A natural problem in combinatorial rigidity theory concerns the determination of the rigidity or flexibility of bar-joint frameworks in $\mathbb{R}^d$ that admit some non-trivial symmetry. When $d=2$ there is a large literature on this…

Combinatorics · Mathematics 2025-09-30 Sean Dewar , Georg Grasegger , Eleftherios Kastis , Anthony Nixon