English
Related papers

Related papers: Angular constraints on planar frameworks

200 papers

In this article, we investigate the multi-parametric matroid problem. The weights of the elements of the matroid's ground set depend linearly on an arbitrary but fixed number of parameters, each of which is taken from a real interval. The…

Combinatorics · Mathematics 2025-03-13 Nils Hausbrandt , Stefan Ruzika

We prove a topological rigidity result for simple, thick, hyperbolic P-manifolds of dimension 2: isomorphism of the fundamental groups implies homeomorphism of the P-manifolds. An immediate application is a diagram rigidity theorem for…

Group Theory · Mathematics 2007-05-23 J. -F. Lafont

We define a special case of tree decompositions for planar graphs that respect a given embedding of the graph. We study the analogous width of the resulting decomposition we call the embedded-width of a plane graph. We show both upper…

Discrete Mathematics · Computer Science 2017-03-23 Glencora Borradaile , Jeff Erickson , Hung Le , Robbie Weber

We investigate the structure of conformally rigid graphs. Graphs are conformally rigid if introducing edge weights cannot increase (decrease) the second (last) eigenvalue of the Graph Laplacian. Edge-transitive graphs and distance-regular…

Combinatorics · Mathematics 2025-06-26 João Gouveia , Stefan Steinerberger , Rekha R. Thomas

We introduce a two-dimensional discrete-time dynamical system which represents the evolution of an angle and angular velocity. While the angle evolves by a fixed amount in every step, the evolution of the angular velocity is governed by a…

Dynamical Systems · Mathematics 2024-12-20 Aakash Khandelwal , Ranjan Mukherjee

In this short note we make a few remarks on a class of generalized incidence matrices whose matroids do not depend on the orientation of the underlying graph and natural commutative algebras associated to such matrices.

Combinatorics · Mathematics 2020-05-14 Boris Shapiro , Arkady Vaintrob

Graphs and hypergraphs combine expressive modeling power with algorithmic efficiency for a wide range of applications. Hedgegraphs generalize hypergraphs further by grouping hyperedges under a color/hedge. This allows hedgegraphs to model…

Data Structures and Algorithms · Computer Science 2025-10-30 Karthekeyan Chandrasekaran , Chandra Chekuri , Weihang Wang , Weihao Zhu

In this paper, we investigate a family of graphs associated to collections of arcs on surfaces. These {\it multiarc graphs} naturally interpolate between arc graphs and flip graphs, both well studied objects in low dimensional geometry and…

Geometric Topology · Mathematics 2019-03-01 Hugo Parlier , Ashley Weber

We characterize 2-dimensional complexes associated canonically with basis graphs of matroids as simply connected triangle-square complexes satisfying some local conditions. This proves a version of a (disproved) conjecture by Stephen Maurer…

Combinatorics · Mathematics 2018-12-10 Jérémie Chalopin , Victor Chepoi , Damian Osajda

We consider a many-to-one variant of the stable matching problem. More concretely, we consider the variant of the stable matching problem where one side has a matroid constraint. Furthermore, we consider the situation where the preference…

Computer Science and Game Theory · Computer Science 2022-09-08 Naoyuki Kamiyama

In this thesis we consider ordered graphs (that is, graphs with a fixed linear ordering on their vertices). We summarize and further investigations on the number of edges an ordered graph may have while avoiding a fixed forbidden ordered…

Discrete Mathematics · Computer Science 2009-07-16 Craig Weidert

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

An open problem in convex geometry asks whether two simplices $A,B\subseteq\mathbb{R}^d$, both containing the origin in their convex hulls, admit a polynomial-length sequence of vertex exchanges transforming $A$ into $B$ while maintaining…

Combinatorics · Mathematics 2025-11-25 Kristóf Bérczi , Benedek Nádor

Motivated by Kontsevich's graph complexes, this paper gives a systematic study of matroid complexes. We construct deletion and contraction bicomplexes on the vector space spanned by matroid classes equipped with ground-set orientations,…

Combinatorics · Mathematics 2026-05-26 Juliette Bruce , Jacob Bucciarelli , Bailee Zacovic

We show that static data structure lower bounds in the group (linear) model imply semi-explicit lower bounds on matrix rigidity. In particular, we prove that an explicit lower bound of $t \geq \omega(\log^2 n)$ on the cell-probe complexity…

Data Structures and Algorithms · Computer Science 2019-02-15 Zeev Dvir , Alexander Golovnev , Omri Weinstein

The theory of matroids or combinatorial geometries originated in linear algebra and graph theory, and has deep connections with many other areas, including field theory, matching theory, submodular optimization, Lie combinatorics, and total…

Combinatorics · Mathematics 2021-11-18 Federico Ardila

Let $\mathcal{P}$ be a set of $n=2m+1$ points in the plane in general position. We define the graph $GM_\mathcal{P}$ whose vertex set is the set of all plane matchings on $\mathcal{P}$ with exactly $m$ edges. Two vertices in…

Computational Geometry · Computer Science 2024-10-10 Oswin Aichholzer , Anna Brötzner , Daniel Perz , Patrick Schnider

For each odd integer $k\ge 5$, we prove that, if $M$ is a simple rank-$r$ binary matroid with no odd circuit of length less than $k$ and with $|M| > k 2^{r-k+1}$, then $M$ is isomorphic to a restriction of the rank-$r$ binary affine…

Combinatorics · Mathematics 2014-02-25 Jim Geelen

We pursue a study of the Generalized Demand Matching problem, a common generalization of the $b$-Matching and Knapsack problems. Here, we are given a graph with vertex capacities, edge profits, and asymmetric demands on the edges. The goal…

Data Structures and Algorithms · Computer Science 2017-05-31 Sara Ahmadian , Zachary Friggstad

The mutually enriching relationship between graphs and matroids has motivated discoveries in both fields. In this paper, we exploit the similar relationship between embedded graphs and delta-matroids. There are well-known connections…

Combinatorics · Mathematics 2019-03-04 Carolyn Chun , Iain Moffatt , Steven D. Noble , Ralf Rueckriemen