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Related papers: Counting cospectral graphs obtained via switching

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We introduce the concept of pattern graphs--directed acyclic graphs representing how response patterns are associated. A pattern graph represents an identifying restriction that is nonparametrically identified/saturated and is often a…

Methodology · Statistics 2020-12-04 Yen-Chi Chen

L. A. Bunimovich and B. Z. Webb developed a theory for transforming a finite weighted graph while preserving its spectrum, referred as isospectral reduction theory. In this work we extend this theory to a class of operators on Banach spaces…

Dynamical Systems · Mathematics 2018-06-27 Pedro Duarte , Maria Joana Torres

A $\mathbb{T}$-gain graph is a simple graph in which a unit complex number is assigned to each orientation of an edge, and its inverse is assigned to the opposite orientation. The associated adjacency matrix is defined canonically, and is…

Combinatorics · Mathematics 2023-04-18 Aniruddha Samanta , M. Rajesh Kannan

We describe a framework for counting and enumerating various types of crossing-free geometric graphs on a planar point set. The framework generalizes ideas of Alvarez and Seidel, who used them to count triangulations in time $O(2^nn^2)$…

Computational Geometry · Computer Science 2016-04-20 Manuel Wettstein

In this paper, we propose algorithms for the graph isomorphism (GI) problem that are based on the eigendecompositions of the adjacency matrices. The eigenvalues of isomorphic graphs are identical. However, two graphs $ G_A $ and $ G_B $ can…

Discrete Mathematics · Computer Science 2019-08-14 Stefan Klus , Tuhin Sahai

We investigate the spectrum of the non-backtracking matrix of a graph. In particular, we show how to obtain eigenvectors of the non-backtracking matrix in terms of eigenvectors of a smaller matrix. Furthermore, we find an expression for the…

Combinatorics · Mathematics 2020-11-19 Cory Glover , Mark Kempton

In this paper we consider the concept of preintersection numbers of a graph. These numbers are determined by the spectrum of the adjacency matrix of the graph, and generalize the intersection numbers of a distance-regular graph. By using…

Combinatorics · Mathematics 2016-04-20 A. Abiad , E. R. van Dam , M. A. Fiol

Recent work has introduced sparse exchangeable graphs and the associated graphex framework, as a generalization of dense exchangeable graphs and the associated graphon framework. The development of this subject involves the interplay…

Probability · Mathematics 2020-02-12 Christian Borgs , Jennifer T. Chayes , Henry Cohn , Victor Veitch

Computing subgraph frequencies is a fundamental task that lies at the core of several network analysis methodologies, such as network motifs and graphlet-based metrics, which have been widely used to categorize and compare networks from…

Data Structures and Algorithms · Computer Science 2021-12-30 Pedro Ribeiro , Pedro Paredes , Miguel E. P. Silva , David Aparicio , Fernando Silva

In this short note, we introduce cospectral graphons, paralleling the notion of cospectral graphs. As in the graph case, we give three equivalent definitions: by equality of spectra, by equality of cycle densities, and by a unitary…

Combinatorics · Mathematics 2024-11-21 Jan Hladký , Daniel Iľkovič , Jared León , Xichao Shu

We present a general method for obtaining the spectra of large graphs with short cycles using ideas from statistical mechanics of disordered systems. This approach leads to an algorithm that determines the spectra of graphs up to a high…

Disordered Systems and Neural Networks · Physics 2023-01-12 D. Bollé , F. L. Metz , I. Neri

We generalize the scattering transform to graphs and consequently construct a convolutional neural network on graphs. We show that under certain conditions, any feature generated by such a network is approximately invariant to permutations…

Information Theory · Computer Science 2020-09-10 Dongmian Zou , Gilad Lerman

In a graph, the switching operation reverses adjacencies between a subset of vertices and the others. For a hereditary graph class $\mathcal{G}$, we are concerned with the maximum subclass and the minimum superclass of $\mathcal{G}$ that…

Data Structures and Algorithms · Computer Science 2024-08-15 Dhanyamol Antony , Yixin Cao , Sagartanu Pal , R. B. Sandeep

We study how the number $c(X)$ of components of a graph $X$ can be expressed through the number and properties of the components of a quotient graph $X/\sim.$ We partially rely on classic qualifications of graph homomorphisms such as…

Combinatorics · Mathematics 2016-07-25 Daniela Bubboloni

In this article, we develop a perturbative technique to construct families of non-isomorphic discrete graphs which are isospectral for the standard (also called normalised) Laplacian and its signless version. We use vertex contractions as a…

Combinatorics · Mathematics 2022-07-11 Fernando Lledó , John S. Fabila-Carrasco , Olaf Post

The asymmetric coloring number of a graph is the minimum number of colors needed to color its vertices, so that no non-trivial automorphism preserves the color classes. We investigate the asymmetric coloring number of graphs that are…

Classical graph matching aims to find a node correspondence between two unlabeled graphs of known topologies. This problem has a wide range of applications, from matching identities in social networks to identifying similar biological…

Signal Processing · Electrical Eng. & Systems 2024-10-28 Hang Liu , Anna Scaglione , Hoi-To Wai

Graph representations offer powerful and intuitive ways to describe data in a multitude of application domains. Here, we consider stochastic processes generating graphs and propose a methodology for detecting changes in stationarity of such…

Machine Learning · Computer Science 2021-02-11 Daniele Zambon , Cesare Alippi , Lorenzo Livi

We propose a generic framework to describe classical Ising-like models defined on arbitrary graphs. The energy spectrum is shown to be the Hadamard transform of a suitably defined sparse "coding" vector associated with the graph. We expect…

Statistical Mechanics · Physics 2015-01-28 Rémy Mosseri

Let $n$ be any positive integer and let $F_n$ be the friendship (or Dutch windmill) graph with $2n+1$ vertices and $3n$ edges. Here we study graphs with the same adjacency spectrum as the $F_n$. Two graphs are called cospectral if the…

Combinatorics · Mathematics 2013-07-23 Alireza Abdollahi , Shahrooz Janbaz , Mohammad Reza Oboudi