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Related papers: On Two Laplacian Matrices for Skew Gain Graphs

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Let $G$ be a group. A group is said to be $k$-generated if it can be generated by its $k$ elements. A generating set of $G$ is called a minimal generating set if no proper subset of it generates $G.$ A minimal generating set of a group can…

Combinatorics · Mathematics 2025-01-20 Kavita Samant , A. Satyanarayana Reddy

We consider the problem of matrix completion with graphs as side information depicting the interrelations between variables. The key challenge lies in leveraging the similarity structure of the graph to enhance matrix recovery. Existing…

Machine Learning · Computer Science 2025-02-13 Yao Wang , Yiyang Yang , Kaidong Wang , Shanxing Gao , Xiuwu Liao

A complex unit gain graph (or ${\mathbb T}$-gain graph) is a triple $\Phi=(G, {\mathbb T}, \varphi)$ (or $(G, \varphi)$ for short) consisting of a simple graph $G$, as the underlying graph of $(G, \varphi)$, the set of unit complex numbers…

Combinatorics · Mathematics 2020-01-07 Shengjie He , Rong-Xia Hao , Fengming Dong

We develop the theory of fractional revival in the quantum walk on a graph using its Laplacian matrix as the Hamiltonian. We first give a spectral characterization of Laplacian fractional revival, which leads to a polynomial time algorithm…

Combinatorics · Mathematics 2020-10-21 Ada Chan , Bobae Johnson , Mengzhen Liu , Malena Schmidt , Zhanghan Yin , Hanmeng Zhan

Let $G$ be a bipartite graph on $n$ vertices with the Laplacian matrix $L_G$. When $G$ is a tree, inequalities involving coefficients of immanantal polynomials of $L_G$ are known as we go up $GTS_n$ poset of unlabelled trees with $n$…

Combinatorics · Mathematics 2023-08-01 Mukesh Kumar Nagar

A signed graph has edge signs. A gain graph has oriented edge gains drawn from a group. We define the combination of the two for the abelian case, in which each oriented edge of a signed graph has a gain from an abelian group, concentrating…

Combinatorics · Mathematics 2022-06-22 Laura Anderson , Ting Su , Thomas Zaslavsky

Let $\Gamma = (G, \sigma)$ be a signed graph, where $G = (V(G),E(G))$ is an (unsigned) graph, called the underlying graph. The net Laplacian matrix of $\Gamma$ is defined as $L^{\pm}(\Gamma) = D^{\pm}(\Gamma) - A(\Gamma)$, where…

Combinatorics · Mathematics 2023-10-20 Zhuang Xiong

Let $(G,w)$ be an undirected weighted graph. The group inverse of $(G,w)$ is the weighted graph with the adjacency matrix $A^{\#}$, where $A$ is the adjacency matrix of $(G,w)$. We study the group inverse of singular weighted trees. It is…

Combinatorics · Mathematics 2023-04-07 Raju Nandi

This work explores the definiteness of the weighted graph Laplacian matrix with negative edge weights. The definiteness of the weighted Laplacian is studied in terms of certain matrices that are related via congruent and similarity…

Optimization and Control · Mathematics 2015-03-03 Daniel Zelazo , Mathias Bürger

Let $\tau(G)$ and $\kappa'(G)$ denote the edge-connectivity and the spanning tree packing number of a graph $G$, respectively. Proving a conjecture initiated by Cioaba and Wong, Liu et al. in 2014 showed that for any simple graph $G$ with…

Combinatorics · Mathematics 2018-08-21 Ruifang Liu , Hong-Jian Lai , Yingzhi Tian

We define the induced arboricity of a graph $G$, denoted by ${\rm ia}(G)$, as the smallest $k$ such that the edges of $G$ can be covered with $k$ induced forests in $G$. This notion generalizes the classical notions of the arboricity and…

Combinatorics · Mathematics 2018-03-07 Maria Axenovich , Philip Dörr , Jonathan Rollin , Torsten Ueckerdt

A gain graph is a triple (G,h,H), where G is a connected graph with an arbitrary, but fixed, orientation of edges, H is a group, and h is a homomorphism from the free group on the edges of G to H. A gain graph is called balanced if the…

Combinatorics · Mathematics 2010-01-24 Konstantin Rybnikov , Thomas Zaslavsky

We define the Laplacian matrix and the Jacobian group of a finite graph of groups. We prove analogues of the matrix tree theorem and the class number formula for the order of the Jacobian of a graph of groups. Given a group $G$ acting on a…

Combinatorics · Mathematics 2023-07-27 Margaret Meyer , Dmitry Zakharov

Real-world data is often represented through the relationships between data samples, forming a graph structure. In many applications, it is necessary to learn this graph structure from the observed data. Current graph learning research has…

Machine Learning · Statistics 2025-07-15 Abdullah Karaaslanli , Bisakh Banerjee , Tapabrata Maiti , Selin Aviyente

Let $k$ be a positive integer and let $G$ be a simple graph of order $n$ with minimum degree $\delta$. A graph $G$ is said to have property $P(k, d)$ if it contains $k$ edge-disjoint spanning trees and an additional forest $F$ with edge…

Combinatorics · Mathematics 2026-01-14 Yongbin Gao , Ligong Wang

This paper explores interlacing inequalities in the Laplacian spectrum of signed cycles and investigates interlacing relationship between the spectrum of the net-Laplacian of a signed graph and its subgraph formed by removing a vertex…

Combinatorics · Mathematics 2023-10-19 Satyam Guragain , Ravi Srivastava

We consider the problem of learning a sparse undirected graph underlying a given set of multivariate data. We focus on graph Laplacian-related constraints on the sparse precision matrix that encodes conditional dependence between the random…

Machine Learning · Statistics 2021-11-17 Jitendra K. Tugnait

The inducibility of a graph represents its maximum density as an induced subgraph over all possible sequences of graphs of size growing to infinity. This invariant of graphs has been extensively studied since its introduction in $1975$ by…

Optimization and Control · Mathematics 2025-12-19 Daniel Brosch , Diane Puges

We study the problem of generating graph signals from unknown distributions defined over given graphs, relevant to domains such as recommender systems or sensor networks. Our approach builds on generative diffusion models, which are well…

Machine Learning · Computer Science 2025-10-07 Sergio Rozada , Vimal K. B. , Andrea Cavallo , Antonio G. Marques , Hadi Jamali-Rad , Elvin Isufi

This paper aims to study in more depth the relation between growth in matrix groups ${{\rm SL_2}}(\mathbf{F})$ and ${{\rm Aff}}(\mathbf{F})$ over a field $\mathbf{F}$ by multiplication and geometric incidence estimates, associated with the…

Combinatorics · Mathematics 2019-02-27 Misha Rudnev , Ilya D. Shkredov