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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

We show that universal rigidity of a generic bar and joint framework (G,p) in the line depends on more than the ordering of the vertices. In particular, we construct examples of one-dimensional generic frameworks with the same graph and…

Combinatorics · Mathematics 2021-04-06 Bryan Chen , Robert Connelly , Anthony Nixon , Louis Theran

Let $G$ be a graph on $n$ nodes. In this note, we prove that if $G$ is $(r+1)$-vertex connected, $1 \leq r \leq n-2$, then there exists a configuration $p$ in general position in $R^r$ such that the bar framework $(G,p)$ is universally…

Metric Geometry · Mathematics 2014-08-18 A. Y. Alfakih

A bar-joint framework $(G,p)$ is the combination of a graph $G$ and a map $p$ assigning positions, in some space, to the vertices of $G$. The framework is rigid if every edge-length-preserving continuous motion of the vertices arises from…

Combinatorics · Mathematics 2021-12-21 Sean Dewar , John Hewetson , Anthony Nixon

The minimal infinitesimal rigidity of bar-joint frameworks in the non-Euclidean spaces (R^2, ||.||_q) are characterised in terms of (2,2)-tight graphs. Specifically, a generically placed bar-joint framework (G,p) in the plane is minimally…

Metric Geometry · Mathematics 2017-05-17 Derek Kitson , Stephen Power

We investigate structural and rigidity properties of \emph{Lie skew braces} (LSBs), objects essentially known in the literature as \emph{post--Lie groups}, obtained by endowing a manifold with two compatible group laws that share the same…

Group Theory · Mathematics 2026-02-26 Marco Damele , Andrea Loi

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

We show that if the joints of a bar and joint framework $(G,p)$ are positioned as `generically' as possible subject to given symmetry constraints and $(G,p)$ possesses a `fully-symmetric' infinitesimal flex (i.e., the velocity vectors of…

Metric Geometry · Mathematics 2009-11-13 Bernd Schulze

A configuration p in r-dimensional Euclidean space is a finite collection of points (p^1,...,p^n) that affinely span R^r. A bar framework, denoted by G(p), in R^r is a simple graph G on n vertices together with a configuration p in R^r. A…

Metric Geometry · Mathematics 2010-09-20 A. Y. Alfakih , Yinyu Ye

A bar-joint framework $(G,p)$ in $\mathbb{R}^d$ is rigid if the only edge-length preserving continuous motions of the vertices arise from isometries of $\mathbb{R}^d$. It is known that, when $(G,p)$ is generic, its rigidity depends only on…

Combinatorics · Mathematics 2023-03-27 Georg Grasegger , Hakan Guler , Bill Jackson , Anthony Nixon

A (bar-and-joint) framework is a set of points in a normed space with a set of fixed distance constraints between them. Determining whether a framework is locally rigid - i.e. whether every other suitably close framework with the same…

Metric Geometry · Mathematics 2024-01-18 Sean Dewar

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

A $d$-dimensional bar-and-joint framework $(G,p)$ with underlying graph $G$ is called universally rigid if all realizations of $G$ with the same edge lengths, in all dimensions, are congruent to $(G,p)$. A graph $G$ is said to be…

Combinatorics · Mathematics 2025-02-07 Guilherme Zeus Dantas e Moura , Tibor Jordán , Corwin Silverman

We consider a class of nonlinear non-diagonal elliptic systems with $p$-growth and establish the $L^q$-integrability for all $q\in [p,p+2]$ of any weak solution provided the corresponding right hand side belongs to the corresponding…

Analysis of PDEs · Mathematics 2018-03-06 Miroslav Bulíček , Martin Kalousek , Petr Kaplický , Václav Mácha

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 develop a rigidity theory for bar-joint frameworks in Euclidean $d$-space in which specified classes of edges are allowed to change length in a coordinated fashion that requires differences of lengths to be preserved within each class.…

Metric Geometry · Mathematics 2022-06-14 Bernd Schulze , Hattie Serocold , Louis Theran

The famous example of the double-Watt mechanism given by Connelly and Servatius raises some problems concerning the classical definitions of higher-order flexibility and rigidity, respectively. Recently, the author was able to give a proper…

Algebraic Geometry · Mathematics 2025-02-11 Georg Nawratil

A linearly constrained framework in $\mathbb{R}^d$ is a bar-joint framework where, in addition, vertices with loops are constrained to lie in given affine subspaces. In the generic case, when each vertex is incident to sufficiently many…

Combinatorics · Mathematics 2026-05-19 Zakir Deniz , Hakan Guler , Anthony Nixon

Regrasping on fixtures is a promising approach to reduce pose uncertainty in robotic assembly, but conventional rigid fixtures lack adaptability and require dedicated designs for each part. To overcome this limitation, we propose a soft jig…

Robotics · Computer Science 2025-09-18 Takuya Kiyokawa , Zhengtao Hu , Weiwei Wan , Kensuke Harada

A $d$-dimensional (bar-and-joint) framework $(G,p)$ consists of a graph $G=(V,E)$ and a realisation $p:V\to \mathbb{R}^d$. It is rigid if every continuous motion of the vertices which preserves the lengths of the edges is induced by an…

History and Overview · Mathematics 2025-08-19 James Cruickshank , Bill Jackson , Tibor Jordán , Shin-ichi Tanigawa