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Related papers: A new kind of $A_{\p}$-matrix for mixed graphs

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Properties of graphs that can be characterized by the spectrum of the adjacency matrix of the graph have been studied systematically recently. Motivated by the complexity of these properties, we show that there are such properties for which…

Combinatorics · Mathematics 2020-01-28 Omid Etesami , Willem H. Haemers

Let $G$ be a simple, connected graph and let $A(G)$ be the adjacency matrix of $G$. If $D(G)$ is the diagonal matrix of the vertex degrees of $G$, then for every real $\alpha \in [0,1]$, the matrix $A_{\alpha}(G)$ is defined as…

Combinatorics · Mathematics 2020-08-25 Mainak Basunia , Iswar Mahato , M. Rajesh Kannan

We introduce a definition of algorithmic symmetry able to capture essential aspects of geometric symmetry. We review, study and apply a method for approximating the algorithmic complexity (also known as Kolmogorov-Chaitin complexity) of…

Computational Complexity · Computer Science 2018-03-07 Hector Zenil , Narsis A. Kiani , Jesper Tegnér

We introduce a new combinatorial abstraction for the graphs of polyhedra. The new abstraction is a flexible framework defined by combinatorial properties, with each collection of properties taken providing a variant for studying the…

Combinatorics · Mathematics 2012-11-02 Edward D. Kim

The $A_{\alpha}$-matrix of a graph $G$ is the convex linear combination of the adjacency matrix $A(G)$ and the diagonal matrix of vertex degrees $D(G)$, i.e., $A_{\alpha}(G) = \alpha D(G) + (1 - \alpha)A(G)$, where $0\leq\alpha \leq1$. The…

Combinatorics · Mathematics 2023-08-16 Yanting Zhang , Ligong Wang

A matching of a graph is a subset of edges no two of which share a common vertex, and a maximum matching is a matching of maximum cardinality. In a $b$-matching every vertex $v$ has an associated bound $b_v$, and a maximum $b$-matching is a…

Data Structures and Algorithms · Computer Science 2019-04-24 Yuval Emek , Shay Kutten , Mordechai Shalom , Shmuel Zaks

Matrix weights satisfying a Muckenhoupt $A_p$-condition relative to a family of anisotropic balls in $\mathbb{R}^d$ defined by a pseudo-metric are studied. It is shown that such matrix weights satisfy a doubling condition and a reverse…

Functional Analysis · Mathematics 2025-10-06 Morten Nielsen

Graph matching aims at finding the vertex correspondence between two unlabeled graphs that maximizes the total edge weight correlation. This amounts to solving a computationally intractable quadratic assignment problem. In this paper we…

Machine Learning · Statistics 2019-07-23 Zhou Fan , Cheng Mao , Yihong Wu , Jiaming Xu

This paper introduces a graph Laplacian regularization in the hyperspectral unmixing formulation. The proposed regularization relies upon the construction of a graph representation of the hyperspectral image. Each node in the graph…

Computer Vision and Pattern Recognition · Computer Science 2014-10-15 Rita Ammanouil , André Ferrari , Cédric Richard

In this paper, we explore the concept of the ``matrix product of graphs," initially introduced by Prasad, Sudhakara, Sujatha, and M. Vinay. This operation involves the multiplication of adjacency matrices of two graphs with assigned labels,…

Combinatorics · Mathematics 2023-12-15 Farzad Maghsoudi , Babak Miraftab , Sho Suda

To apportion a complex matrix means to apply a similarity so that all entries of the resulting matrix have the same magnitude. We initiate the study of apportionment, both by unitary matrix similarity and general matrix similarity. There…

Combinatorics · Mathematics 2024-06-04 Antwan Clark , Bryan A. Curtis , Edinah K. Gnang , Leslie Hogben

We introduce a concept of similarity between vertices of directed graphs. Let G_A and G_B be two directed graphs. We define a similarity matrix whose (i, j)-th real entry expresses how similar vertex j (in G_A) is to vertex i (in G_B. The…

Information Retrieval · Computer Science 2007-05-23 Vincent Blondel , Anahi Gajardo , Maureen Heymans , Pierre Senellart , Paul Van Dooren

The degree-diameter problem seeks to find the maximum possible order of a graph with a given (maximum) degree and diameter. It is known that graphs attaining the maximum possible value (the Moore bound) are extremely rare, but much activity…

Combinatorics · Mathematics 2016-05-03 Dominique Buset , Mourad El Amiri , Grahame Erskine , Hebert Pérez-Rosés , Mirka Miller

We introduce the warping matrix which is a new description of oriented knots from a viewpoint of warping degree.

Geometric Topology · Mathematics 2015-08-17 Ayaka Shimizu

We study homomorphism polynomials, which are polynomials that enumerate all homomorphisms from a pattern graph $H$ to $n$-vertex graphs. These polynomials have received a lot of attention recently for their crucial role in several new…

Computational Complexity · Computer Science 2020-11-17 Balagopal Komarath , Anurag Pandey , C. S. Rahul

Graph is an abstract representation commonly used to model networked systems and structure. In problems across various fields, including computer vision and pattern recognition, and neuroscience, graphs are often brought into comparison (a…

Optimization and Control · Mathematics 2022-03-04 Quoc Van Tran , Hyo-Sung Ahn

Motivated by discrete Laplacian differential operators with various accuracy orders in numerical analysis, we introduce new matrices attached to a simple graph that can be considered graph Laplacians with higher accuracy. In particular, we…

Combinatorics · Mathematics 2025-04-09 Mary Yoon

Harary and Schwenk posed the problem forty years ago: Which graphs have distinct adjacency eigenvalues? In this paper, we obtain a necessary and sufficient condition for an Hermitian matrix with simple spectral radius and distinct…

Combinatorics · Mathematics 2014-05-26 Xueliang Li , Jianfeng Wang , Qiongxiang Huang

Matrices are typically considered over fields or rings. Motivated by applications in parametric differential equations and data-driven modeling, we suggest to study matrices with entries from a Hilbert space and present an elementary theory…

Numerical Analysis · Mathematics 2025-05-09 Stanislav Budzinskiy

If $G$ is a looped graph, then its adjacency matrix represents a binary matroid $M_{A}(G)$ on $V(G)$. $M_{A}(G)$ may be obtained from the delta-matroid represented by the adjacency matrix of $G$, but $M_{A}(G)$ is less sensitive to the…

Combinatorics · Mathematics 2013-09-04 Robert Brijder , Hendrik Jan Hoogeboom , Lorenzo Traldi