English
Related papers

Related papers: On the Spectral Gap of a Quantum Graph

200 papers

We study the symmetry properties of the spectra of normalized Laplacians on signed graphs. We find a new machinery that generates symmetric spectra for signed graphs, which includes bipartiteness of unsigned graphs as a special case.…

Combinatorics · Mathematics 2016-02-16 Fatihcan M. Atay , Bobo Hua

In this paper, we study the entries of the principal eigenvector of the signless Laplacian matrix of a hypergraph. More precisely, we obtain bounds for this entries. These bounds are computed trough other important parameters, such as…

Combinatorics · Mathematics 2020-05-01 Kauê Cardoso

It is known that, for an oriented hypergraph with (vertex) coloring number $\chi$ and smallest and largest normalized Laplacian eigenvalues $\lambda_1$ and $\lambda_N$, respectively, the inequality $\chi\geq…

Combinatorics · Mathematics 2026-02-23 Lies Beers , Raffaella Mulas

This article presents a novel and succinct algorithmic framework via alternating quantum walks, unifying quantum spatial search, state transfer and uniform sampling on a large class of graphs. Using the framework, we can achieve exact…

Quantum Physics · Physics 2025-04-22 Qingwen Wang , Ying Jiang , Lvzhou Li

Let G be a simple undirected connected graph. In this paper, new upper bounds on the distance Laplacian spectral radius of G are obtained. Moreover, new lower and upper bounds for the distance signless Laplacian spectral radius of G are…

Combinatorics · Mathematics 2019-06-14 Roberto C. Díaz , Ana I. Julio , Oscar Rojo

Because of the significant increase in size and complexity of the networks, the distributed computation of eigenvalues and eigenvectors of graph matrices has become very challenging and yet it remains as important as before. In this paper…

Numerical Analysis · Mathematics 2017-11-27 Konstantin Avrachenkov , Philippe Jacquet , Jithin Sreedharan

The imbalance of an edge $e=\{u,v\}$ in a graph is defined as $i(e)=|d(u)-d(v)|$, where $d(\cdot)$ is the vertex degree. The irregularity $I(G)$ of $G$ is then defined as the sum of imbalances over all edges of $G$. This concept was…

Combinatorics · Mathematics 2013-08-20 Felix Goldberg

In this paper we study the spectrum of the random geometric graph $G(n,r)$, in a regime where the graph is dense and highly connected. In the \erdren $G(n,p)$ random graph it is well known that upon connectivity the spectrum of the…

Probability · Mathematics 2020-04-13 Kartick Adhikari , Robert J. Adler , Omer Bobrowski , Ron Rosenthal

We propose a new family of combinatorial inference problems for graphical models. Unlike classical statistical inference where the main interest is point estimation or parameter testing, combinatorial inference aims at testing the global…

Statistics Theory · Mathematics 2018-02-14 Matey Neykov , Junwei Lu , Han Liu

In this work we introduce a concept of complexity for undirected graphs in terms of the spectral analysis of the Laplacian operator defined by the incidence matrix of the graph. Precisely, we compute the norm of the vector of eigenvalues of…

Information Theory · Computer Science 2022-03-23 Diego M. Mateos , Federico Morana , Hugo Aimar

Learning a graph with a specific structure is essential for interpretability and identification of the relationships among data. It is well known that structured graph learning from observed samples is an NP-hard combinatorial problem. In…

Machine Learning · Statistics 2019-09-26 Sandeep Kumar , Jiaxi Ying , Jos'e Vin'icius de M. Cardoso , Daniel P. Palomar

We construct models of exactly solvable two-particle quantum graphs with certain non-local two-particle interactions, establishing appropriate boundary conditions via suitable self-adjoint realisations of the two-particle Laplacian. Showing…

Mathematical Physics · Physics 2017-02-20 Jens Bolte , George Garforth

This research focuses on analyzing the depth of generalized binomial edge ideals. We extend the notion of $d$-compatible map for the pairs of a complete graph and an arbitrary graph, and using it, we give a combinatorial lower bound for the…

Commutative Algebra · Mathematics 2024-01-15 Anuvinda J , Ranjana Mehta , Kamalesh Saha

The spectral properties of the Laplacian on a class of quantum graphs with random metric structure are studied. Namely, we consider quantum graphs spanned by the simple $\ZZ^d$-lattice with $\delta$-type boundary conditions at the vertices,…

Mathematical Physics · Physics 2009-11-13 Frédéric Klopp , Konstantin Pankrashkin

The paper is concerned with the number of open gaps in spectra of periodic quantum graphs. The well-known conjecture by Bethe and Sommerfeld (1933) says that the number of open spectral gaps for a system periodic in more than one direction…

Mathematical Physics · Physics 2017-11-16 Pavel Exner , Ondřej Turek

The unitary evolution maps in closed chaotic quantum graphs are known to have universal spectral correlations, as predicted by random matrix theory. In chaotic graphs with absorption the quantum maps become non-unitary. We show that their…

Chaotic Dynamics · Physics 2013-08-13 Boris Gutkin , Vladimir Al. Osipov

The Laplacian eigenvalues of a network play an important role in the analysis of many structural and dynamical network problems. In this paper, we study the relationship between the eigenvalue spectrum of the normalized Laplacian matrix and…

Social and Information Networks · Computer Science 2013-10-21 Zhengwei Wu , Victor M. Preciado

We describe a new method for constraining Laplacian spectra of hyperbolic surfaces and 2-orbifolds. The main ingredient is consistency of the spectral decomposition of integrals of products of four automorphic forms. Using a combination of…

High Energy Physics - Theory · Physics 2024-01-23 Petr Kravchuk , Dalimil Mazac , Sridip Pal

Here we have investigated a few properties of the eigenvalues of normalized (geometric) graph Laplacian in different graphs. Preservation of eigenvalue 1 from a particular subgraph to the entire graph, the spectrum of the graph constructed…

Combinatorics · Mathematics 2014-03-07 Anirban Banerjee

Our goal in this paper is to find an estimate for the spectral gap of the Laplacian on a 2-simplicial complex consisting on a triangulation of a complete graph. An upper estimate is given by generalizing the Cheeger constant. The lower…

Spectral Theory · Mathematics 2020-10-28 Yassin Chebbi