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Related papers: Spectral statistics for scaling quantum graphs

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We give variants of the Krein bound and the absolute bound for graphs with a spectrum similar to that of a strongly regular graph. In particular, we investigate what we call approximately strongly regular graphs. We apply our results to…

Combinatorics · Mathematics 2022-08-10 Ferdinand Ihringer

We consider random geometric graphs on the plane characterized by a non-uniform density of vertices. In particular, we introduce a graph model where $n$ vertices are independently distributed in the unit disc with positions, in polar…

Disordered Systems and Neural Networks · Physics 2022-04-06 C. T. Martinez-Martinez , J. A. Mendez-Bermudez , Francisco A. Rodrigues , Ernesto Estrada

We give a new formula for computing the isospectral reduction of a matrix (and graph) down to a submatrix (or subgraph). Using this, we generalize the notion of isospectral reductions. In addition, we give a procedure for constructing a…

Combinatorics · Mathematics 2022-12-02 Mark Kempton , John Tolbert

Typical eigenstates of quantum systems, whose classical limit is chaotic, are well approximated as random states. Corresponding eigenvalue spectra is modeled through appropriate ensemble of random matrix theory. However, a small subset of…

Quantum Physics · Physics 2018-06-21 S. Harshini Tekur , Santosh Kumar , M. S. Santhanam

The statistical properties of the quantum chaotic spectra have been studied, so far, only up to the second order correlation effects. The numerical as well as the analytical evidence that random matrix theory can successfully model the…

Condensed Matter · Physics 2009-10-28 Pragya Shukla

The generalized pseudospectral method is employed for the accurate calculation of eigenvalues, densities and expectation values for the spiked harmonic oscillators. This allows \emph{nonuniform} and \emph{optimal} spatial discretization of…

Quantum Physics · Physics 2015-06-16 Amlan K. Roy

We investigate the bottom of the spectra of infinite quantum graphs, i.e., Laplace operators on metric graphs having infinitely many edges and vertices. We introduce a new definition of the isoperimetric constant for quantum graphs and then…

Spectral Theory · Mathematics 2018-12-17 Aleksey Kostenko , Noema Nicolussi

Spectral features are widely incorporated within Graph Neural Networks (GNNs) to improve their expressive power, or their ability to distinguish among non-isomorphic graphs. One popular example is the usage of graph Laplacian eigenvectors…

Machine Learning · Computer Science 2025-09-29 Snir Hordan , Maya Bechler-Speicher , Gur Lifshitz , Nadav Dym

The random matrix ensembles are applied to the quantum statistical systems. The quantum systems are studied using the finite dimensional real, complex and quaternion Hilbert spaces of the eigenfunctions. The linear operators describing the…

Statistical Mechanics · Physics 2007-05-23 Maciej M. Duras

Spectral analysis plays a crucial role in high-dimensional statistics, where determining the asymptotic distribution of various spectral statistics remains a challenging task. Due to the difficulties of deriving the analytic form, recent…

Statistics Theory · Mathematics 2025-04-02 Guoyu Zhang , Dandan Jiang , Fang Yao

The autocorrelation function of spectral determinants is proposed as a convenient tool for the characterization of spectral statistics in general, and for the study of the intimate link between quantum chaos and random matrix theory, in…

chao-dyn · Physics 2009-10-28 S. Kettemann , D. Klakow , U. Smilansky

Solutions to the stochastic wave equation on the unit sphere are approximated by spectral methods. Strong, weak, and almost sure convergence rates for the proposed numerical schemes are provided and shown to depend only on the smoothness of…

Numerical Analysis · Mathematics 2023-12-06 David Cohen , Annika Lang

Solving a longstanding problem on equiangular lines, we determine, for each given fixed angle and in all sufficiently large dimensions, the maximum number of lines pairwise separated by the given angle. Fix $0 < \alpha < 1$. Let…

Combinatorics · Mathematics 2022-03-01 Zilin Jiang , Jonathan Tidor , Yuan Yao , Shengtong Zhang , Yufei Zhao

A general treatment of the spectral problem of quantum graphs and tight-binding models in finite Hilbert spaces is given. The direct spectral problem and the inverse spectral problem are written in terms of simple algebraic equations…

Quantum Physics · Physics 2022-10-12 Emerson Sadurni , Thomas H Seligman

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

McKay proved that the limiting spectral measures of the ensembles of $d$-regular graphs with $N$ vertices converge to Kesten's measure as $N\to\infty$. In this paper we explore the case of weighted graphs. More precisely, given a large…

Probability · Mathematics 2013-07-01 Leo Goldmakher , Cap Khoury , Steven J. Miller , Kesinee Ninsuwan

This paper addresses the problem of finding the densest $k$-vertex subgraph in an arbitrary graph. This problem is NP-hard and has important applications in social network analysis, fraud detection, recommendation systems, and…

Quantum Physics · Physics 2026-05-01 Yu. A. Biriukov , R. D. Morozov , I. V. Dyakonov , S. S. Straupe

Spectral statistics of quantum systems have been studied in detail using the nearest neighbour level spacings, which for generic chaotic systems follows random matrix theory predictions. In this work, the probability density of the closest…

Chaotic Dynamics · Physics 2019-01-23 Shashi C. L. Srivastava , Arul Lakshminarayan , Steven Tomsovic , Arnd Bäcker

For non-Hermitian equilateral q-pointed star-shaped quantum graphs of paper I [Can. J. Phys. 90, 1287 (2012), arXiv 1205.5211] we show that due to certain dynamical aspects of the model as controlled by the external, rotation-symmetric…

Quantum Physics · Physics 2015-07-14 Miloslav Znojil

Graph states are a unique resource for quantum information processing, such as measurement-based quantum computation. Here, we theoretically investigate using continuous-variable graph states for single-parameter quantum metrology,…

Quantum Physics · Physics 2020-11-04 Yunkai Wang , Kejie Fang