English
Related papers

Related papers: The Brush Number of the Two-Dimensional Torus

200 papers

This article introduces efficient and user-friendly tools for analyzing the intersection curve between a ringed torus and an irreducible quadric surface. Without loose of generality, it is assumed that the torus is centered at the origin,…

Algebraic Geometry · Mathematics 2025-03-13 Laureano Gonzalez-Vega , Jorge Caravantes , Gema M. Diaz-Toca , Mario Fioravanti

A contraction sequence of a graph consists of iteratively merging two of its vertices until only one vertex remains. The recently introduced twin-width graph invariant is based on contraction sequences. More precisely, if one puts red edges…

Data Structures and Algorithms · Computer Science 2022-06-02 Édouard Bonnet , Eun Jung Kim , Amadeus Reinald , Stéphan Thomassé

In 1973, Altshuler characterized the $6$-regular triangulations on the torus to be precisely those that are obtained from a regular triangulation of the $r \times s$ toroidal grid where the vertices in the first and last column are…

Combinatorics · Mathematics 2022-10-11 Brahadeesh Sankarnarayanan

The problem of defining correctly geometric objects such as the curvature is a hard one in discrete geometry. In 2009, Ollivier defined a notion of curvature applicable to a wide category of measured metric spaces, in particular to graphs.…

Differential Geometry · Mathematics 2014-03-10 Benoît Loisel , Pascal Romon

While the notion of arboricity of a graph is well-known in graph theory, very few results are dedicated to the minimal number of trees covering the edges of a graph, called the tree number of a graph.

Discrete Mathematics · Computer Science 2020-08-03 Natalia Vanetik

A queue layout of a graph consists of a linear order on the vertices and an assignment of the edges to queues, such that no two edges in a single queue are nested. The minimum number of queues needed in a queue layout of a graph is called…

Discrete Mathematics · Computer Science 2016-08-23 Veit Wiechert

As a means to better understanding manifolds with positive curvature, there has been much recent interest in the study of non-negatively curved manifolds which contain either a point or an open dense set of points at which all 2-planes have…

Differential Geometry · Mathematics 2012-03-12 Martin Kerin

We discuss, following Mikhalkin, Brugall\'e, and many others, the counting of curves on toric surfaces with prescribed genus, Newton polygon, and intersection pattern with the toric boundary divisor, both at assigned and unassigned points.…

Algebraic Geometry · Mathematics 2025-11-27 Thomas Dedieu

Motzkin and Straus established a close connection between the maximum clique problem and a solution (namely graph-Lagrangians) to the maximum value of a class of homogeneous quadratic multilinear functions over the standard simplex of the…

Combinatorics · Mathematics 2013-12-30 Qingsong Tang , Yuejian Peng , Xiangde Zhang , Cheng Zhao

The edge blow-up of a graph $F$ is the graph obtained from replacing each edge in $F$ by a clique of the same size where the new vertices of the cliques are all different. In this article, we concern about the Tur\'an problem for the edge…

Combinatorics · Mathematics 2020-08-25 Anyao Wang , Xinmin Hou , Boyuan Liu , Yue Ma

Transcendental Brauer elements are notoriously difficult to compute. Work of Wittenberg, and later, Ieronymou, gives a method for computing 2-torsion transcendental classes on surfaces that have a genus 1 fibration with rational 2-torsion…

Algebraic Geometry · Mathematics 2012-02-29 Bianca Viray

Knot mosaics were introduced by Kauffman and Lomonaco in the context of quantum knots, but have since been studied for their own right. A classical knot mosaic is formed on a square grid. In this work, we identify opposite edges of the…

Geometric Topology · Mathematics 2025-11-06 Kendall Heiney , Margaret Kipe , Samantha Pezzimenti , Kaelyn Pontes , Luc Ta

The quandle coloring quiver was introduced by Cho and Nelson as a categorification of the quandle coloring number. In some cases, it has been shown that the quiver invariant offers more information than other quandle enhancements. In this…

Quantum Algebra · Mathematics 2023-07-11 Tirasan Khandhawit , Korn Kruaykitanon , Puttipong Pongtanapaisan

The boxicity of a graph is the smallest dimension $d$ allowing a representation of it as the intersection graph of a set of $d$-dimensional axis-parallel boxes. We present a simple general approach to determining the boxicity of a graph…

Combinatorics · Mathematics 2025-01-10 Marco Caoduro , András Sebő

A graph is near-planar if it can be obtained from a planar graph by adding an edge. We show the surprising fact that it is NP-hard to compute the crossing number of near-planar graphs. A graph is 1-planar if it has a drawing where every…

Computational Geometry · Computer Science 2012-03-28 Sergio Cabello , Bojan Mohar

The study of the graph diameter of polytopes is a classical open problem in polyhedral geometry and the theory of linear optimization. In this paper we continue the investigation initiated in [4] by introducing a vast hierarchy of…

Combinatorics · Mathematics 2014-11-27 Steffen Borgwardt , Jesús A. De Loera , Elisabeth Finhold

In a series of papers, P. Blasiak et al. developed a wide-ranging generalization of Bell numbers (and of Stirling numbers of the second kind) that appears to be relevant to the so-called Boson normal ordering problem. They provided a…

Discrete Mathematics · Computer Science 2013-12-11 Pietro Codara , Ottavio M. D'Antona , Pavol Hell

Among the knots that are the connected sum of two torus knots with cobordism distance 1, we characterize those that have 4-dimensional clasp number at least 2, and we show that their n-fold connected self-sum has 4-dimensional clasp number…

Geometric Topology · Mathematics 2021-08-27 Peter Feller , JungHwan Park

A drawing of a graph is {\em pseudolinear} if there is a pseudoline arrangement such that each pseudoline contains exactly one edge of the drawing. The {\em pseudolinear crossing number} of a graph $G$ is the minimum number of pairwise…

Combinatorics · Mathematics 2019-04-29 Cesar Hernandez-Velez , Jesus Leanos , Gelasio Salazar

A $k$-truss is an edge-induced subgraph $H$ such that each of its edges belongs to at least $k-2$ triangles of $H$. This notion has been introduced around ten years ago in social network analysis and security, as a form of cohesive subgraph…

Data Structures and Algorithms · Computer Science 2020-10-05 Alessio Conte , Roberto Grossi , Andrea Marino , Luca Versari