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We consider a hierarchy of graph invariants that naturally extends the spectral invariants defined by F\"urer (Lin. Alg. Appl. 2010) based on the angles formed by the set of standard basis vectors and their projections onto eigenspaces of…

Computational Complexity · Computer Science 2025-05-06 V. Arvind , Frank Fuhlbrück , Johannes Köbler , Oleg Verbitsky

We study countable graphs that -- up to isomorphism and with probability one -- arise from a random process, in a similar fashion as the Rado graph. Unlike in the classical case, we do not require that probabilities assigned to pairs of…

Combinatorics · Mathematics 2026-01-23 Ziemowit Kostana , Jarosław Swaczyna , Agnieszka Widz

With the recent rise in the amount of structured data available, there has been considerable interest in methods for machine learning with graphs. Many of these approaches have been kernel methods, which focus on measuring the similarity…

Machine Learning · Computer Science 2017-08-07 P. -L. Giscard , R. C. Wilson

We consider a distance-regular graph $\G$ with diameter $d \ge 3$ and eigenvalues $k=\theta_0>\theta_1>... >\theta_d$. We show the intersection numbers $a_1, b_1$ satisfy $$ (\theta_1 + {k \over a_1+1}) (\theta_d + {k \over a_1+1}) \ge -…

Combinatorics · Mathematics 2007-05-23 Aleksandar Jurisic , Jack Koolen , Paul Terwilliger

We prove new properties of the non-backtracking graph and the non-backtracking Laplacian for graphs. In particular, among other results, we prove that two simple graphs are isomorphic if and only if their corresponding non-backtracking…

Combinatorics · Mathematics 2023-05-30 Raffaella Mulas , Dong Zhang , Giulio Zucal

We show that a simple Markov chain, the Glauber dynamics, can efficiently sample independent sets almost uniformly at random in polynomial time for graphs in a certain class. The class is determined by boundedness of a new graph parameter…

Discrete Mathematics · Computer Science 2020-12-07 Martin Dyer , Catherine Greenhill , Haiko Müller

In this article we construct a series of new infinite families of strongly regular graphs with the same parameters as the point-graphs of non-singular quadrics in PG(n,2).

Combinatorics · Mathematics 2016-06-20 S. G. Barwick , Wen-Ai Jackson , Tim Penttila

This paper considers the problem of multi-sample nonparametric comparison of counting processes with panel count data, which arise naturally when recurrent events are considered. Such data frequently occur in medical follow-up studies and…

Statistics Theory · Mathematics 2009-04-21 N. Balakrishnan , Xingqiu Zhao

Characterizations graphs of some classes to induce periodic Grover walks have been studied for recent years. In particular, for the strongly regular graphs, it has been known that there are only three kinds of such graphs. Here, we focus on…

Combinatorics · Mathematics 2018-05-22 Yusuke Yoshie

Two graphs are isomorphic exactly when they admit the same number of homomorphisms from every graph. Hence, a graph is recognized up to isomorphism by homomorphism counts over the class of all graphs. Restricting to a specific graph class…

Discrete Mathematics · Computer Science 2026-01-15 Marek Černý

We investigate the paramater of the average range of $M$-Lipschitz mapping of a given graph. We focus on well-known classes such as paths, complete graphs, complete bipartite graphs and cycles and show closed formulas for computing this…

Combinatorics · Mathematics 2018-01-18 Jan Bok

Dynamic systems characterized by diversified evolutions are not only more flexible, but also more resilient to attacks, failures and changing conditions. This article addresses the quantification of the diversity of non-linear transient…

Physics and Society · Physics 2008-01-07 Luciano da Fontoura Costa

Coarse graph theory concerns finding 'coarse' analogues of graph theory theorems, replacing disjointness with being far apart. One of the most interesting open questions is to find a coarse analogue of Menger's theorem, which characterizes…

Combinatorics · Mathematics 2025-08-21 Tung Nguyen , Alex Scott , Paul Seymour

The simple connected graphs may be classified by their cycle composition (number and lengths of cycles). This work derives the counting series of the simple connected graphs that have cycles of unrestricted number and length, but no…

Combinatorics · Mathematics 2018-08-21 Richard J. Mathar

It is known that up to certain pathologies, a compact metric graph with standard vertex conditions has a Baire-generic set of choices of edge lengths such that all Laplacian eigenvalues are simple and have eigenfunctions that do not vanish…

Combinatorics · Mathematics 2022-05-25 Lior Alon

For causal discovery in the presence of latent confounders, constraints beyond conditional independences exist that can enable causal discovery algorithms to distinguish more pairs of graphs. Such constraints are not well-understood yet. In…

Machine Learning · Computer Science 2024-06-14 Thijs van Ommen

A result of Erd\"os and R\'enyi shows that for a fixed integer n almost all graphs satisfy the n-e.c. adjacency property. However, there are few explicit constructions of n e.c. graphs for n > 2, and almost all known families of n-e.c.…

Combinatorics · Mathematics 2011-07-26 Natalie Mullin

A parallel $d$-stable trace is a closed walk which traverses every edge of a graph exactly twice in the same direction and for every vertex $v$, there is no subset $X \subseteq N(v)$ with $1 \leq |N| \leq d$ such that every time the walk…

Combinatorics · Mathematics 2019-08-09 Jernej Rus

Let $\lambda\geq2$ be an integer. For strongly regular graphs with parameters $(v, k, a,c)$ and smallest eigenvalue $-\lambda$, Neumaier gave two bounds on $c$ by using algebraic property of strongly regular graphs. In this paper, we will…

Combinatorics · Mathematics 2021-09-10 Jack H. Koolen , Brhane Gebremichel , Jae Young Yang , Qianqian Yang

In this note, we try to analyze and clarify the intriguing interplay between some counting problems related to specific thermalized weighted graphs and random walks consistent with such graphs.

Statistical Mechanics · Physics 2015-05-13 Thierry Huillet
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