English
Related papers

Related papers: Isospectral graphs with identical nodal counts

200 papers

Recently, much of the existing work in manifold learning has been done under the assumption that the data is sampled from a manifold without boundaries and singularities or that the functions of interest are evaluated away from such points.…

Artificial Intelligence · Computer Science 2012-11-29 Mikhail Belkin , Qichao Que , Yusu Wang , Xueyuan Zhou

In this paper, we introduce a graph structure called linear dependence graph of a finite dimensional vector space over a finite field. Some basic properties of the graph like connectedness, completeness, planarity, clique number, chromatic…

Combinatorics · Mathematics 2017-03-31 A. K. Bhuniya , Sushobhan Maity

In this paper we generalise the results on eigenvalues and eigenvectors of unnormalized (combinatorial) Laplacian of two-dimensional grid presented by Edwards:2013 first to a grid graph of any dimension, and second also to other types of…

Classical Analysis and ODEs · Mathematics 2019-09-02 Mieczysław A. Kłopotek

The study of very large graphs is a prominent theme in modern-day mathematics. In this paper we develop a rigorous foundation for studying the space of finite labelled graphs and their limits. These limiting objects are naturally countable…

Combinatorics · Mathematics 2021-05-27 Apoorva Khare , Bala Rajaratnam

We consider the Dirac equation on periodic networks (quantum graphs). The self-adjoint quasi periodic boundary conditions are derived. The secular equation allowing us to find the energy spectrum of the Dirac particles on periodic quantum…

Quantum Physics · Physics 2021-08-11 J. R. Yusupov , K. K. Sabirov , D. U. Matrasulov

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

We present a method which enables one to construct isospectral objects, such as quantum graphs and drums. One aspect of the method is based on representation theory arguments which are shown and proved. The complementary part concerns…

Mathematical Physics · Physics 2009-11-13 Ram Band , Ori Parzanchevski , Gilad Ben-Shach

Berry and Wang [Phys. Rev. A {\bf 83}, 042317 (2011)] show numerically that a discrete-time quantum random walk of two noninteracting particles is able to distinguish some non-isomorphic strongly regular graphs from the same family. Here we…

Quantum Physics · Physics 2013-08-27 Kenneth Rudinger , John King Gamble , Eric Bach , Mark Friesen , Robert Joynt , S. N. Coppersmith

We prove that for every pair of quantum isomorphic graphs, their block trees and their block graphs are isomorphic, and that such an isomorphism can be chosen so that the corresponding blocks are quantum isomorphic -- in particular,…

Combinatorics · Mathematics 2025-10-23 Amaury Freslon , Paul Meunier , Pegah Pournajafi

This paper establishes an upper bound on the number of generalized cospectral mates of simple graphs, where the generalized spectrum consists of the spectrum of a graph and its complement. Moving beyond the classical problem of identifying…

Combinatorics · Mathematics 2026-03-24 Muhammad Raza , Obaid Ullah Ahmad , Mudassir Shabbir , Waseem Abbas

We present a geometrical construction of families of finite isospectral graphs labelled by different partitions of a natural number $r$ of given length $s$ (the number of summands). Isospectrality here refers to the discrete magnetic…

Spectral Theory · Mathematics 2024-01-30 John Stewart Fabila-Carrasco , Fernando Lledó , Olaf Post

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

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 study the interplay between spectrum, geometry and boundary conditions for two distinguished self-adjoint realisations of the Laplacian on infinite metric graphs, the so-called riedrichs and Neumann extensions. We introduce a new…

Spectral Theory · Mathematics 2025-10-03 Marco Düfel , James B. Kennedy , Delio Mugnolo , Marvin Plümer , Matthias Täufer

We initiate a systematic study of quantum properties of finite graphs, namely, quantum asymmetry, quantum symmetry, and quantum isomorphism. We define the Schmidt alternative for a class of graphs, which reveals to be a useful tool for…

Operator Algebras · Mathematics 2024-05-09 Paul Meunier

A connected graph can be associated with two distinct evolution algebras. In the first case, the structural matrix is the adjacency matrix of the graph itself. In the second case, the structural matrix is the transition probabilities matrix…

Combinatorics · Mathematics 2024-05-22 Paula Cadavid , Mary Luz Rodiño Montoya , Pablo M. Rodriguez , Sebastian J. Vidal

In this article, we introduce a geometric and a spectral preorder relation on the class of weighted graphs with a magnetic potential. The first preorder is expressed through the existence of a graph homomorphism respecting the magnetic…

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

We prove that the spectrum of an individual chaotic quantum graph shows universal spectral correlations, as predicted by random--matrix theory. The stability of these correlations with regard to non--universal corrections is analyzed in…

Chaotic Dynamics · Physics 2009-11-10 Sven Gnutzmann , Alexander Altland

The spectrum of the normalized Laplacian matrix cannot determine the number of edges in a graph, however finding constructions of cospectral graphs with differing number of edges has been elusive. In this paper we use basic properties of…

Combinatorics · Mathematics 2014-10-27 Steve Butler

We present enumeration results on the number of connected graphs up to 10 vertices for which there is at least one other graph with the same spectrum (a cospectral mate), or at least one other graph with the same Smith normal form…

Combinatorics · Mathematics 2020-08-14 Aida Abiad , Carlos A. Alfaro
‹ Prev 1 3 4 5 6 7 10 Next ›