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The Subgraph Isomorphism problem asks, given a host graph G on n vertices and a pattern graph P on k vertices, whether G contains a subgraph isomorphic to P. The restriction of this problem to planar graphs has often been considered. After…

Discrete Mathematics · Computer Science 2015-03-19 Paul Bonsma

We prove a complete complexity classification theorem for the planar eight-vertex model. For every parameter setting in ${\mathbb C}$ for the eight-vertex model, the partition function is either (1) computable in P-time for every graph, or…

Computational Complexity · Computer Science 2026-02-13 Austen Fan , Jin-Yi Cai , Shuai Shao , Zhuxiao Tang

A graph $G$ is called matching covered if all of its edges are contained in some perfect matching of $G$. Furthermore, a cycle $C \subseteq G$ is called conformal if $G - V(C)$ has a perfect matching and $G$ itself is called cycle-conformal…

Combinatorics · Mathematics 2026-02-10 Maximilian Gorsky , Clemens Kuske

Inference and learning of graphical models are both well-studied problems in statistics and machine learning that have found many applications in science and engineering. However, exact inference is intractable in general graphical models,…

Machine Learning · Statistics 2015-02-04 Jason K. Johnson , Diane Oyen , Michael Chertkov , Praneeth Netrapalli

We present an application of the Grassmann algebra to the problem of the monomer-dimer statistics on a two-dimensional square lattice. The exact partition function, or total number of possible configurations, of a system of dimers with a…

Statistical Mechanics · Physics 2015-06-18 Nicolas Allegra , Jean-Yves Fortin

Quadrilateral layouts on surfaces are valuable in texture mapping, and essential in generation of quadrilateral meshes and in fitting splines. Previous work has characterized such layouts as a special metric on a surface or as a meromorphic…

Computational Geometry · Computer Science 2020-12-18 Kendrick M. Shepherd , René R. Hiemstra , Thomas J. R. Hughes

To any graph with external half-edges and internal masses, we associate canonical integrals which depend non-trivially on particle masses and momenta, and are always finite. They are generalised Feynman integrals which satisfy graphical…

Mathematical Physics · Physics 2023-11-23 Francis Brown

We present the theory of multifunctions applied to graphs. Its interesting feature is that walks are recognized as iterations. We consider the graphs with arbitrary number of vertices which are determined by multifunctions. The mutually…

General Mathematics · Mathematics 2017-11-02 Artur Gizycki

We present the algebraic representation and basic algorithms for MultiAspect Graphs (MAGs). A MAG is a structure capable of representing multilayer and time-varying networks, as well as higher-order networks, while also having the property…

Discrete Mathematics · Computer Science 2016-09-27 Klaus Wehmuth , Éric Fleury , Artur Ziviani

Modern methods of graph theory describe a graph up to isomorphism, which makes it difficult to create mathematical models for visualizing graph drawings on a plane. The topological drawing of the planar part of a graph allows representing…

Combinatorics · Mathematics 2024-08-01 Sergey Kurapov , Maxim Davidovsky

We present a method for computing the framing on the cohomology of graph hypersurfaces defined by the Feynman differential form. This answers a question of Bloch, Esnault and Kreimer in the affirmative for an infinite class of graphs for…

Algebraic Geometry · Mathematics 2013-01-15 Francis Brown , Dzmitry Doryn

Graphical model selection is a seemingly impossible task when many pairs of variables are never jointly observed; this requires inference of conditional dependencies with no observations of corresponding marginal dependencies. This…

Statistics Theory · Mathematics 2023-02-16 Giuseppe Vinci , Gautam Dasarathy , Genevera I. Allen

We work out the theory of fractional isomorphism of graphons as a generalization to the classical theory of fractional isomorphism of finite graphs. The generalization is given in terms of homomorphism densities of finite trees and it is…

Combinatorics · Mathematics 2021-02-05 Jan Grebík , Israel Rocha

A function $f$ of a graph is called a complete graph invariant if the isomorphism of graphs $G$ and $H$ is equivalent to the equality $f(G)=f(H)$. If, in addition, $f(G)$ is a graph isomorphic to $G$, then $f$ is called a canonical form for…

Computational Complexity · Computer Science 2011-11-09 Johannes Koebler , Oleg Verbitsky

The known Pfaffian structure of the boundary spin correlations, and more generally order-disorder correlation functions, is given a new explanation through simple topological considerations within the model's random current representation.…

Mathematical Physics · Physics 2022-01-25 Michael Aizenman , Hugo Duminil-Copin , Vincent Tassion , Simone Warzel

The splitting number is effective to distinguish the embedded topology of plane curves, and it is not determined by the fundamental group of the complement of the plane curve. In this paper, we give a generalization of the splitting number,…

Algebraic Geometry · Mathematics 2018-04-20 Taketo Shirane

Given a graph $G$, we form a random subgraph $G_p$ by including each edge of $G$ independently with probability $p$. We provide an asymptotic expansion of the expected number of independent sets in random subgraphs of regular bipartite…

Combinatorics · Mathematics 2026-05-14 Anna Geisler , Mihyun Kang , Michail Sarantis , Ronen Wdowinski

Exchangeable graphs arise via a sampling procedure from measurable functions known as graphons. A natural estimation problem is how well we can recover a graphon given a single graph sampled from it. One general framework for estimating a…

Statistics Theory · Mathematics 2015-05-13 Diana Cai , Nathanael Ackerman , Cameron Freer

We construct a family of Pfaffian point processes relevant for the harmonic analysis on the infinite symmetric group. The correlation functions of these processes are representable as Pfaffians with matrix valued kernels. We give explicit…

Representation Theory · Mathematics 2012-02-14 Eugene Strahov

Graph drawing addresses the problem of finding a layout of a graph that satisfies given aesthetic and understandability objectives. The most important objective in graph drawing is minimization of the number of crossings in the drawing, as…

Computational Geometry · Computer Science 2014-01-22 Mohamed A. El-Sayed , S. Abdel-Khalek , Hanan H. Amin