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Related papers: The eigenvalues of $q$-Kneser graphs

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In this paper, we deal with a q-Dirac system. We investigate some spectral properties and the asymptotic behavior of the eigenvalues and the eigenfunctions of this q-Dirac system.

Classical Analysis and ODEs · Mathematics 2018-12-11 Fatma Hıra

We improve recent results relating graph eigenvalues to other graph parameters like girth, domination number, and minimum degree.

Combinatorics · Mathematics 2007-05-23 Vladimir Nikiforov

A few properties of unitary Cayley graphs are explored using their eigenvalues. It is shown that the adjacency algebra of a unitary Cayley graph is a coherent algebra. Finally, a class of unitary Cayley graphs that are distance regular are…

Number Theory · Mathematics 2017-07-11 A. Satyanarayana Reddy

We will prove that some weighted graphs on the distance $k$-graph of hypercubes approximate the $q$-Hermite polynomial of a $q$-gaussian variable by providing an appropriate matrix model.

Operator Algebras · Mathematics 2012-08-21 Hun Hee Lee , Nobuaki Obata

Let $G$ be a graph, and let $\lambda(G)$ denote the smallest eigenvalue of $G$. First, we provide an upper bound for $\lambda(G)$ based on induced bipartite subgraphs of $G$. Consequently, we extract two other upper bounds, one relying on…

Combinatorics · Mathematics 2024-04-16 Aryan Esmailpour , Sara Saeedi Madani , Dariush Kiani

In this paper we study when the $q$-distance matrix of a distance-regular graph has few distinct eigenvalues. We mainly concentrate on diameter 3.

Combinatorics · Mathematics 2024-01-12 Mamoon Abdullah , Brhane Gebremichel , Sakander Hayat , Jack H. Koolen

In this paper, we study the $q$-distance matrix for a distance-regular graph and show that the $q$-distance matrix of a distance-regular graph with classical parameters ($D, q, \alpha, \beta$) has exactly three distinct eigenvalues, of…

Combinatorics · Mathematics 2023-05-25 Jack H. Koolen , Mamoon Abdullah , Brhane Gebremichel , Sakander Hayat

We formulate a notion of the quantum automorphism group of a $2$-graph. After some preliminary computations, we define quantum isomorphism between a pair of $2$-graphs. We produce a `non-trivial' example of a pair of $2$-graphs that are not…

Operator Algebras · Mathematics 2025-04-01 Soumalya Joardar , Atibur Rahaman , Jitender Sharma

We give combinatorial proofs for some identities involving binomial sums that have no closed form.

Combinatorics · Mathematics 2011-07-07 Mark Shattuck , Tamás Waldhauser

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

We quantize the regularity properties of classical graphs that determine spin models for singly-generated Yang-Baxter planar algebras, including the Kauffman polynomial, and construct explicit examples. A source of examples comes from…

Operator Algebras · Mathematics 2026-02-16 Néstor Bravo Hernández , Roberto Hernández Palomares , Fabio Viales Solís

Weight-equitable partitions of graphs, which are a natural extension of the well-known equitable partitions, have been shown to be a powerful tool to weaken the regularity assumption in several well-known eigenvalue bounds. In this work we…

Combinatorics · Mathematics 2021-09-08 Aida Abiad , Christopher Hojny , Sjanne Zeijlemaker

An eigenvalue of the adjacency matrix of a graph is said to be \emph{main} if the all-1 vector is not orthogonal to the associated eigenspace. In this work, we approach the main eigenvalues of some graphs. The graphs with exactly two main…

Combinatorics · Mathematics 2026-02-17 Nair Abreu , Domingos M. Cardoso , Francisca A. M. França , Cybele T. M. Vinagre

We use two variational techniques to prove upper bounds for sums of the lowest several eigenvalues of matrices associated with finite, simple, combinatorial graphs. These include estimates for the adjacency matrix of a graph and for both…

Spectral Theory · Mathematics 2013-08-27 Evans M. Harell , Joachim Stubbe

Let $q$ be a positve integer, and $G$ be a $q$-partite simple graph on $qn$ vertices, with $n$ vertices in each vertex class. Let $\delta={k_q \over k_q+1}$, where $k_q=q+O(\log{q})$. If each vertex of $G$ is adjacent to at least $\delta n$…

Combinatorics · Mathematics 2008-07-29 Bela Csaba

In this paper we constructed new q-extension of Bernstein polynomials. Fron those q-Berstein polynomials, we give some interesting properties and we investigate some applications related this q-Bernstein polynomials.

Number Theory · Mathematics 2015-05-19 Taekyun Kim

In this article we obtain a general polynomial identity in $k$ variables, where $k\geq 2$ is an arbitrary positive integer. We use this identity to give a closed-form expression for the entries of the powers of a $k \times k$ matrix.…

Combinatorics · Mathematics 2019-01-01 James Mc Laughlin , B. Sury

Sharp bounds on the least eigenvalue of an arbitrary graph are presented. Necessary and sufficient (just sufficient) conditions for the lower (upper) bound to be attained are deduced using edge clique partitions. As an application, we prove…

Combinatorics · Mathematics 2022-02-25 Domingos M. Cardoso , Inês Serôdio Costa , Rui Duarte

We review quantum chaos on graphs. We construct a unitary operator which represents the quantum evolution on the graph and study its spectral and wavefunction statistics. This operator is the analogue of the classical evolution operator on…

Chaotic Dynamics · Physics 2007-05-23 Tsampikos Kottos

An oscillation formula is established for the $k$-th eigenvector (assumed to be simple and with non-zero entries) of a weighted graph operator. The formula directly attributes the number of sign changes exceeding $k-1$ to the cycles in the…

Spectral Theory · Mathematics 2025-07-31 Gregory Berkolaiko , Jared C. Bronski , Mark Goresky