English
Related papers

Related papers: Structural properties of Toeplitz graphs

200 papers

A Toeplitz graph $T_n \langle t_1,t_2,\ldots,t_k\rangle$ is a simple graph with the vertex set $[n]$ such that two vertices $v$ and $w$ are adjacent if and only if $|v-w| = t_i$ for some $i \in [k]$. In this paper, we investigate line…

Combinatorics · Mathematics 2024-06-27 Gi-Sang Cheon , Bumtle Kang , Suh-Ryung Kim , Seyed Ahmad Mojallal , Homoon Ryu

In this paper, structural properties of chordal graphs are analysed, in order to establish a relationship between these structures and integer Laplacian eigenvalues. We present the characterization of chordal graphs with equal vertex and…

Discrete Mathematics · Computer Science 2019-07-12 Nair Maria Maia de Abreu , Claudia Marcela Justel , Lilian Markenzon

In this paper, we study row graphs of Toeplitz matrices. The notion of row graphs was introduced by Greenberg et al. in 1984 and is closely related to the notion of competition graphs, which has been extensively studied since Cohen had…

Combinatorics · Mathematics 2023-05-05 Gi-Sang Cheon , Bumtle Kang , Suh-Ryung Kim , Homoon Ryu

Resolving parameters is a fundamental area of combinatorics with applications not only to many branches of combinatorics but also to other sciences. In this article, we construct a class of Toeplitz graphs, and will be denoted by…

Combinatorics · Mathematics 2021-12-14 Jia-Bao Liu , Ali Zafari

We characterize some graphs with a Gorenstein edge ideal. In particular, we show that if $G$ is a circulant graph with vertex degree at most four or a circulant graph of the form $C_n(1,\ldots, d)$ for some $d\leq n/2$, then $G$ is…

Commutative Algebra · Mathematics 2024-04-11 Ashkan Nikseresht , Mohammad Reza Oboudi

A perfect code in a graph is an independent set of the graph such that every vertex outside the set is adjacent to exactly one vertex in the set. A circulant graph is a Cayley graph of a cyclic group. In this paper we study perfect codes in…

Combinatorics · Mathematics 2024-03-05 Xiaomeng Wang , Oriol Serra , Shou-Jun Xu , Sanming Zhou

Toeplitz matrices are characterized by their constant diagonals, have been extensively studied in various settings, including over real and complex numbers. However, their study over quaternions is quite sparse. In this paper, we…

Functional Analysis · Mathematics 2025-10-07 Muhammad Ahsan Khan , Sohail Khan

In this paper, we use the theory of Riordan matrices to introduce the notion of a Riordan graph. The Riordan graphs are a far-reaching generalization of the well known and well studied Pascal graphs and Toeplitz graphs, and also some other…

Combinatorics · Mathematics 2019-04-16 Gi-Sang Cheon , Ji-Hwan Jung , Sergey Kitaev , Seyed Ahmad Mojallal

The symplectic graph Sp(2d, q) is the collinearity graph of the symplectic space of dimension 2d over a finite field of order q. A k-regular graph on v vertices is a divisible design graph with parameters (v, k, lambda_1, lambda_2 ,m,n) if…

Combinatorics · Mathematics 2022-07-01 Vladislav V. Kabanov

A moplex is a natural graph structure that arises when lifting Dirac's classical theorem from chordal graphs to general graphs. While every non-complete graph has at least two moplexes, little is known about structural properties of graphs…

Combinatorics · Mathematics 2023-02-01 Clément Dallard , Robert Ganian , Meike Hatzel , Matjaž Krnc , Martin Milanič

A graph $G$ is a {\em chordal-$k$-generalized split graph} if $G$ is chordal and there is a clique $Q$ in $G$ such that every connected component in $G[V \setminus Q]$ has at most $k$ vertices. Thus, chordal-$1$-generalized split graphs are…

Discrete Mathematics · Computer Science 2017-04-28 Andreas Brandstädt , Raffaele Mosca

We describe the structure of 2-connected non-planar toroidal graphs with no K_{3,3}-subdivisions, using an appropriate substitution of planar networks into the edges of certain graphs called toroidal cores. The structural result is based on…

Combinatorics · Mathematics 2008-05-06 Andrei Gagarin , Gilbert Labelle , Pierre Leroux

We prove that for any integers $p\geq k\geq 3$ and any $k$-tuple of positive integers $(n_1,\ldots ,n_k)$ such that $p=\sum _{i=1}^k{n_i}$ and $n_1\geq n_2\geq \ldots \geq n_k$, the condition $n_1\leq {p\over 2}$ is necessary and sufficient…

Combinatorics · Mathematics 2018-08-22 Daniela Ferrero , Linda Lesniak

Given two graphs $H_1$ and $H_2$, a graph is $(H_1,\,H_2)$-free if it contains no induced subgraph isomorphic to $H_1$ or $H_2$. For a positive integer $t$, $P_t$ is the chordless path on $t$ vertices. A paraglider is the graph that…

Combinatorics · Mathematics 2019-03-28 Shenwei Huang , T. Karthick

Let $G$ be a graph with the usual shortest-path metric. A graph is $\delta$-hyperbolic if for every geodesic triangle $T$, any side of $T$ is contained in a $\delta$-neighborhood of the union of the other two sides. A graph is chordal if…

Combinatorics · Mathematics 2015-05-22 A. Martínez-Pérez

We investigate the structure of conformally rigid graphs. Graphs are conformally rigid if introducing edge weights cannot increase (decrease) the second (last) eigenvalue of the Graph Laplacian. Edge-transitive graphs and distance-regular…

Combinatorics · Mathematics 2025-06-26 João Gouveia , Stefan Steinerberger , Rekha R. Thomas

The $k$-token graph $T_k(G)$ is the graph whose vertices are the $k$-subsets of vertices of a graph $G$, with two vertices of $T_k(G)$ adjacent if their symmetric difference is an edge of $G$. We explore when $T_k(G)$ is a well-covered…

Combinatorics · Mathematics 2020-10-12 F. M. Abdelmalek , Esther Vander Meulen , Kevin N. Vander Meulen , Adam Van Tuyl

The intention of the paper is to move a step towards a classification of network topologies that exhibit periodic quantum dynamics. We show that the evolution of a quantum system, whose hamiltonian is identical to the adjacency matrix of a…

Quantum Physics · Physics 2007-05-23 Nitin Saxena , Simone Severini , Igor Shparlinski

Strictly Chordality-k graphs (SC_k graphs) are graphs which are either cycle free or every induced cycle is exactly k, for some fixed k, k \geq 3. Note that k = 3 and k = 4 are precisely the Chordal graphs and Chordal Bipartite graphs,…

Discrete Mathematics · Computer Science 2017-09-04 S. Dhanalakshmi , N. Sadagopan

This work concerns the study of properties of a group of Koszul algebras coming from the toric ideals of a chordal bipartite infinite family of graphs (alternately, these rings may be interpreted as coming from determinants of certain…

Commutative Algebra · Mathematics 2021-02-18 Laura Ballard
‹ Prev 1 2 3 10 Next ›