English
Related papers

Related papers: Generic Rigidity Matroids with Dilworth Truncation…

200 papers

A two-dimensional direction-length framework $(G,p)$ consists of a multigraph $G=(V;D,L)$ whose edge set is formed of "direction" edges $D$ and "length" edges $L$, and a realisation $p$ of this graph in the plane. The edges of the framework…

Combinatorics · Mathematics 2016-08-31 Katie Clinch

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

We present necessary and sufficient conditions for the generic rigidity of body-bar frameworks on the three-dimensional fixed torus. These frameworks correspond to infinite periodic body-bar frameworks in $\mathbb{R}^3$ with a fixed…

Metric Geometry · Mathematics 2014-03-05 Elissa Ross

A d-dimensional framework is a graph and a map from its vertices to E^d. Such a framework is globally rigid if it is the only framework in E^d with the same graph and edge lengths, up to rigid motions. For which underlying graphs is a…

Metric Geometry · Mathematics 2021-10-13 Steven J. Gortler , Alexander D. Healy , Dylan P. Thurston

We study the rigidity of body-and-cad frameworks which capture the majority of the geometric constraints used in 3D mechanical engineering CAD software. We present a combinatorial characterization of the generic minimal rigidity of a subset…

Discrete Mathematics · Computer Science 2012-10-19 Audrey Lee-St. John , Jessica Sidman

We develop a combinatorial rigidity theory for symmetric bar-joint frameworks in a general finite dimensional normed space. In the case of rotational symmetry, matroidal Maxwell-type sparsity counts are identified for a large class of…

Metric Geometry · Mathematics 2020-04-17 Derek Kitson , Anthony Nixon , Bernd Schulze

As an extension of a classical tree-partition problem, we consider decompositions of graphs into edge-disjoint (rooted-)trees with an additional matroid constraint. Specifically, suppose we are given a graph $G=(V,E)$, a multiset…

Combinatorics · Mathematics 2011-09-06 Naoki Katoh , Shin-ichi Tanigawa

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 $(G,p)$ in a (non-Euclidean) real normed plane $X$ is the combination of a finite, simple graph $G$ and a placement $p$ of the vertices in $X$. A framework $(G,p)$ is globally rigid in $X$ if every other framework…

Metric Geometry · Mathematics 2024-01-18 Sean Dewar , Anthony Nixon

A tensegrity is a structure made from cables, struts and stiff bars. A $d$-dimensional tensegirty is universally rigid if it is rigid in any dimension $d'$ with $d'\geq d$. The celebrated super stability condition due to Connelly gives a…

Optimization and Control · Mathematics 2020-05-01 Ryoshun Oba , Shin-ichi Tanigawa

Tanigawa (2016) showed that vertex-redundant rigidity of a graph implies its global rigidity in arbitrary dimension. We extend this result to periodic graphs under fixed lattice representations. A periodic graph is vertex-redundantly rigid…

Metric Geometry · Mathematics 2018-04-24 Viktoria E. Kaszanitzky , Csaba Kiraly , Bernd Schulze

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

Motivated by constraint-based CAD software, we develop the foundation for the rigidity theory of a very general model: the body-and-cad structure, composed of rigid bodies in 3D constrained by pairwise coincidence, angular and distance…

Computational Geometry · Computer Science 2010-06-08 Kirk Haller , Audrey Lee-St. John , Meera Sitharam , Ileana Streinu , Neil White

We review some recent results in the generic rigidity theory of planar frameworks with forced symmetry, giving a uniform treatment to the topic. We also give new combinatorial characterizations of minimally rigid periodic frameworks with…

Geometric Topology · Mathematics 2012-03-06 Justin Malestein , Louis Theran

Abstractions of crystalline materials known as periodic body-and-bar frameworks are made of rigid bodies connected by fixed-length bars and subject to the action of a group of translations. In this paper, we give a Maxwell-Laman…

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

We give a combinatorial characterization of generic minimal rigidity for planar periodic frameworks. The characterization is a true analogue of the Maxwell-Laman Theorem from rigidity theory: it is stated in terms of a finite combinatorial…

Combinatorics · Mathematics 2012-10-24 Justin Malestein , Louis Theran

Inspired by a recent result of Brakensiek et al. that symmetric tensor matroids and rigidity matroids are linked by matroid duality, we define abstract symmetric tensor matroids as a dual concept to abstract rigidity matroids and establish…

Combinatorics · Mathematics 2025-03-20 Bill Jackson , Shin-ichi Tanigawa

In "Universal rigidity on the line, point orde" it is shown, answering a question of Jord\'an and Nguyen, that universal rigidity of a generic bar-joint framework in R^1 depends on more than the ordering of the vertices. The graph G that…

Metric Geometry · Mathematics 2022-07-19 Bryan Chen , Robert Connelly , Steven J. Gortler , Anthony Nixon , Louis Theran

We consider the problem of characterising the generic rigidity of bar-joint frameworks in $\mathbb{R}^d$ in which each vertex is constrained to lie in a given affine subspace. The special case when $d=2$ was previously solved by I. Streinu…

Combinatorics · Mathematics 2020-07-03 Bill Jackson , Anthony Nixon , Shin-Ichi Tanigawa

A theorem of Laman gives a combinatorial characterisation of the graphs that admit a realisation as a minimally rigid generic bar-joint framework in $\bR^2$. A more general theory is developed for frameworks in $\bR^3$ whose vertices are…

Combinatorics · Mathematics 2012-10-05 A. Nixon , J. C. Owen , S. C. Power