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In this paper, we propose a new type of graph, denoted as "embedded-graph", and its theory, which employs a distributed representation to describe the relations on the graph edges. Embedded-graphs can express linguistic and complicated…

Discrete Mathematics · Computer Science 2017-09-15 Atsushi Yokoyama

A plabic graph is a planar bicolored graph embedded in a disk, which satisfies some combinatorial conditions. Postnikov's boundary measurement map takes the space of positive edge weights of a plabic graph $G$ to a positroid cell in some…

Combinatorics · Mathematics 2017-03-21 Rachel Karpman , Yi Su

Median graphs are connected graphs in which for all three vertices there is a unique vertex that belongs to shortest paths between each pair of these three vertices. In this paper we provide several novel characterizations of planar median…

Combinatorics · Mathematics 2021-10-19 Carsten R. Seemann , Vincent Moulton , Peter F. Stadler , Marc Hellmuth

A signed graph is a graph whose edges are labelled positive or negative. The sign of a circle (cycle, circuit) is the product of the signs of its edges. Most of the essential properties of a signed graph depend on the signs of its circles.…

Combinatorics · Mathematics 2021-06-16 Thomas Zaslavsky

In this paper, we introduce a connection between two classical concepts of graph theory: \; metric dimension and distinguishing number. For a given graph $G$, let ${\rm dim}(G)$ and $D(G)$ represent its metric dimension and distinguishing…

Combinatorics · Mathematics 2023-12-15 Meysam Korivand , Nasrin Soltankhah

A connected graph is called of non-QE class if it does not admit a quadratic embedding in a Euclidean space. A non-QE graph is called primary if it does not contain a non-QE graph as an isometrically embedded proper subgraph. The graphs on…

Combinatorics · Mathematics 2023-07-24 Nobuaki Obata

We study the metric dimension (strong and weak) of infinite graphs. In particular, our main interest is characterizing infinite graphs with finite dimension. Our main results: (1) graphs with more than one end have infinite strong…

Combinatorics · Mathematics 2026-04-17 Csaba Biró , Caroline E. Boone , Beth Novick , Hazel Torek

Several graph properties are characterized as the class of graphs that admit an orientation avoiding finitely many oriented structures. For instance, if $F_k$ is the set of homomorphic images of the directed path on $k+1$ vertices, then a…

Combinatorics · Mathematics 2020-12-24 Santiago Guzmán-Pro , César Hernández-Cruz

This paper compares the divisorial gonality of a finite graph $G$ to the divisorial gonality of the associated metric graph $\Gamma(G,\mathbb{1})$ with unit lengths. We show that $\text{dgon}(\Gamma(G,\mathbb{1}))$ is equal to the minimal…

Combinatorics · Mathematics 2021-07-07 Josse van Dobben de Bruyn , Harry Smit , Marieke van der Wegen

A mixed graph $\widetilde{G}$ is obtained from a simple undirected graph $G$, the underlying graph of $\widetilde{G}$, by orienting some edges of $G$. Let $c(G)=|E(G)|-|V(G)|+\omega(G)$ be the cyclomatic number of $G$ with $\omega(G)$ the…

Combinatorics · Mathematics 2023-04-14 Shengjie He , Rong-Xia Hao , Hong-Jian Lai , Qiaozhi Geng

A connected subgraph of a graph is isometric if it preserves distances. In this short note, we provide counterexamples to several variants of the following general question: When a graph $G$ is edge covered by connected isometric subgraphs…

Combinatorics · Mathematics 2025-11-06 Paul Bastide , Julien Duron , Jędrzej Hodor , Weichan Liu , Xiangxiang Nie

A subgraph $H$ of a graph $G$ is isometric if the distances between vertices in $H$ coincide with the distances between the corresponding vertices in $G$. We show that for any integer $n\ge 1$, there is a graph on $3^{n+O(\log^2 n)}$…

Combinatorics · Mathematics 2021-06-24 Louis Esperet , Cyril Gavoille , Carla Groenland

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

We say that a metric graph is uniformly bounded if the degrees of all vertices are uniformly bounded and the lengths of edges are pinched between two positive constants; a metric space is approximable by a uniform graph if there is one…

Metric Geometry · Mathematics 2013-06-25 Dmitri Burago , Sergei Ivanov

We compute the quadratic embedding constant for complete bipartite graphs with disjoint edges removed. Moreover, we study the quadratic embedding property for theta graphs, i.e., graphs consisting of three paths with common initial points…

Combinatorics · Mathematics 2024-10-02 Wojciech Młotkowski , Marek Skrzypczyk , Michał Wojtylak

O'Donnell, Wright, Wu and Zhou [SODA 2014] introduced the notion of robustly asymmetric graphs. Roughly speaking, these are graphs in which for every $0 \le \rho \le 1$, every permutation that permutes a $\rho$ fraction of the vertices maps…

Discrete Mathematics · Computer Science 2014-02-06 Uriel Feige

In this paper we study the metric geometry of the space $\Sigma$ of positive invertible elements of a von Neumann algebra ${\mathcal A}$ with a finite, normal and faithful tracial state $\tau$. The trace induces an incomplete Riemannian…

Differential Geometry · Mathematics 2008-08-14 Esteban Andruchow , Gabriel Larotonda

In this paper we investigate invertibility of graphs with a unique perfect matching, i.e. graphs having a unique 1-factor. We recall the new notion of the so-called negatively invertible graphs investigated by the authors in the recent…

Combinatorics · Mathematics 2016-12-08 Sona Pavlikova , Daniel Sevcovic

The metric representation of a vertex $u$ in a connected graph $G$ respect to an ordered vertex subset $W=\{\omega_1, \dots , \omega_n\}\subset V(G)$ is the vector of distances $r(u\vert W)=(d(u,\omega_1), \dots , d(u,\omega_n))$. A vertex…

Combinatorics · Mathematics 2024-10-15 Mercè Mora , María Luz Puertas

A generalization of metric space is presented which is shown to admit a theory strongly related to that of ordinary metric spaces. To avoid the topological effects related to dropping any of the axioms of metric space, first a new, and…

Metric Geometry · Mathematics 2012-01-20 Ittay Weiss