English
Related papers

Related papers: The product structure of squaregraphs

200 papers

We exhibit several families of planar graphs that are minor-minimal intrinsically spherical $3$-linked. A graph is intrinsically spherical 3-linked if it is planar graph that has, in every spherical embedding, a non-split 3-link consisting…

Combinatorics · Mathematics 2021-07-20 Madeleine Burkhart , Andrew Castillo , Jonathan Doane , Joel Foisy , Cristopher Negron

An outerplanar graph is a planar graph that has a planar drawing with all vertices on the unbounded face. The matching complex of a graph is the simplicial complex whose faces are subsets of disjoint edges of the graph. In this paper we…

Combinatorics · Mathematics 2024-11-08 Margaret Bayer , Marija Jelić Milutinović , Julianne Vega

We introduce a new class $\mathcal{G}$ of bipartite plane graphs and prove that each graph in $\mathcal{G}$ admits a proper square contact representation. A contact between two squares is \emph{proper} if they intersect in a line segment of…

Computational Geometry · Computer Science 2021-07-27 Andrew Nathenson

A partial automorphism of a finite graph is an isomorphism between its vertex induced subgraphs. The set of all partial automorphisms of a given finite graph forms an inverse monoid under composition (of partial maps). We describe the…

Combinatorics · Mathematics 2020-02-12 Robert Jajcay , Tatiana Jajcayova , Nóra Szakács , Mária B. Szendrei

A geometric graph is a drawing of a graph in the plane where the vertices are drawn as points in general position and the edges as straight-line segments connecting their endpoints. It is plane if it contains no crossing edges. We study…

Computational Geometry · Computer Science 2025-06-26 Marco Ricci , Jonathan Rollin , André Schulz , Alexandra Weinberger

A graph is \emph{$(\mathcal{I}, \mathcal{F})$-partitionable} if its vertex set can be partitioned into two parts such that one part $\mathcal{I}$ is an independent set, and the other $\mathcal{F}$ induces a forest. A graph is…

Combinatorics · Mathematics 2025-02-27 Zhengjiao Liu , Tao Wang , Xiaojing Yang

We prove that every automorphism of an infinite-dimensional vector space over a field is the product of four involutions, a result that is optimal in the general case. We also characterize the automorphisms that are the product of three…

Rings and Algebras · Mathematics 2020-03-24 Clément de Seguins Pazzis

Albertson and Berman conjectured that every planar graph has an induced forest on half of its vertices. The best known lower bound, due to Borodin, is that every planar graph has an induced forest on two fifths of its vertices. In a related…

Combinatorics · Mathematics 2026-03-19 Glencora Borradaile , Hung Le , Melissa Sherman-Bennett

A connected 3-valent plane graph, whose faces are $q$- or 6-gons only, is called a {\em graph $q_n$}. We classify all graphs $4_n$, which are isometric subgraphs of a $m$-hypercube $H_m$.

Combinatorics · Mathematics 2007-05-23 Michel Deza , Mathieu Dutour-Sikiric , Sergey Shpectorov

In \emph{smooth orthogonal layouts} of planar graphs, every edge is an alternating sequence of axis-aligned segments and circular arcs with common axis-aligned tangents. In this paper, we study the problem of finding smooth orthogonal…

Computational Geometry · Computer Science 2013-12-13 Md. Jawaherul Alam , Michael A. Bekos , Michael Kaufmann , Philipp Kindermann , Stephen G. Kobourov , Alexander Wolff

This article investigates the isomorphism problem for graphs derived from the four standard graph products: Cartesian, Kronecker (direct), strong, and lexicographic product. We provide a complete characterization of all simple connected…

Combinatorics · Mathematics 2025-08-07 Priti Prasanna Mondal , M. Rajesh Kannan , Fouzul Atik

A self-contained graph is an infinite graph which is isomorphic to one of its proper induced subgraphs. In this paper, these graphs are studied by presenting some examples and defining some of their sub-structures such as removable…

Combinatorics · Mathematics 2016-11-04 Mohammad Hadi Shekarriz , Madjid Mirzavaziri

A platypus graph is a non-hamiltonian graph for which every vertex-deleted subgraph is traceable. They are closely related to families of graphs satisfying interesting conditions regarding longest paths and longest cycles, for instance…

Combinatorics · Mathematics 2017-12-15 Jan Goedgebeur , Addie Neyt , Carol T. Zamfirescu

We show that every planar, 4-connected, K2;5-minor- free graph is the square of a cycle of even length at least six.

Combinatorics · Mathematics 2015-08-24 Emily Abernethy Marshall , Liana Yepremyan , Zach Gaslowitz

A reflexive cycle is any reflexive digraph whose underlying undirected graph is a cycle. Call a relational structure Slupecki if its surjective polymorphisms are all essentially unary. We prove that all reflexive cycles of girth at least 4…

Combinatorics · Mathematics 2022-07-14 Isabelle Larivière , Benoit Larose , David Emmanuel Pazmiño Pullas

Graphs that are squares under the gluing algebra arise in the study of homomorphism density inequalities such as Sidorenko's conjecture. Recent work has focused on these homomorphism density applications. This paper takes a new perspective…

Combinatorics · Mathematics 2025-10-08 Karen L. Collins , David Galvin , Christine A. Kelley , Emily McMillon , Amanda Redlich

Product structure theorems are a collection of recent results that have been used to resolve a number of longstanding open problems on planar graphs and related graph classes. One particularly useful version states that every planar graph…

Combinatorics · Mathematics 2024-06-17 Vida Dujmović , Gwenaël Joret , Piotr Micek , Pat Morin , David R. Wood

We prove that, for every positive integer k, there is an integer N such that every 4-connected non-planar graph with at least N vertices has a minor isomorphic to K_{4,k}, the graph obtained from a cycle of length 2k+1 by adding an edge…

Combinatorics · Mathematics 2010-11-11 Guoli Ding , Bogdan Oporowski , Robin Thomas , Dirk Vertigan

We prove that if a graph contains the complete bipartite graph $K_{134, 12}$ as an induced minor, then it contains a cycle of length at most~12 or a theta as an induced subgraph. With a longer and more technical proof, we prove that if a…

Combinatorics · Mathematics 2025-11-04 Maria Chudnovsky , Meike Hatzel , Tuukka Korhonen , Nicolas Trotignon , Sebastian Wiederrecht

A graph drawn on the plane is called $1$-plane if each edge is crossed at most once by another edge. In this paper, we show that every $4$-connected $1$-plane graph has a connected spanning plane subgraph. We also show that there exist…

Combinatorics · Mathematics 2024-04-09 Kenta Noguchi , Katsuhiro Ota , Yusuke Suzuki