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Related papers: On invariant Schreier structures

200 papers

Scale invariance profoundly influences the dynamics and structure of complex systems, spanning from critical phenomena to network architecture. Here, we propose a precise definition of scale-invariant networks by leveraging the concept of a…

Statistical Mechanics · Physics 2024-12-17 Anna Poggialini , Pablo Villegas , Miguel A. Muñoz , Andrea Gabrielli

We provide sufficient conditions for the existence of a trace on the essential $\mathrm{C}^\ast$-algebra of a (not necessarily Hausdorff) \'etale groupoid $G$ which extends an invariant measure $\mu$ on the unit space of $G$. In particular,…

Operator Algebras · Mathematics 2026-03-05 Alistair Miller , Eduardo Scarparo

We study the isoperimetric and spectral profiles of certain families of finitely generated groups defined via actions on labelled Schreier graphs and simple {\em gluing} of such. In one of our simplest constructions---the {\em…

Probability · Mathematics 2020-09-01 Laurent Saloff-Coste-Costeb , Tianyi Zheng

We consider a Random Graph Model on $\mathbb{Z}^{d}$ that incorporates the interplay between the statistics of the graph and the underlying space where the vertices are located. Based on a graphical construction of the model as the…

Statistics Theory · Mathematics 2024-06-19 Andressa Cerqueira , Nancy L. Garcia

Graphs that are squares under the gluing algebra arise in the study of homomorphism density inequalities such as Sidorenko's conjecture. Recent work has focused on these homomorphism density applications. This paper takes a new perspective…

Combinatorics · Mathematics 2025-10-08 Karen L. Collins , David Galvin , Christine A. Kelley , Emily McMillon , Amanda Redlich

We study an important property of shape invariant supersymmetric quantum mechanical systems. Particularly, we demonstrate that each shape invariant supersymmetric system can constitute a $Z_3$-graded topological symmetric algebra. The…

High Energy Physics - Theory · Physics 2015-06-17 V. K. Oikonomou

In the branch of mathematics known as graph theory, graphs are considered as a set of points, called vertices, with connections between these points, called edges. The purpose of this paper is to study mappings between two graphs that have…

Combinatorics · Mathematics 2019-03-19 Jeffrey Beyerl , Cameron Sharpe

In recent years, there has been significant interest in characterizing the induced subgraph obstructions to bounded treewidth and pathwidth. While this has recently been resolved for pathwidth, the case of treewidth remains open, and prior…

Combinatorics · Mathematics 2025-07-31 Maria Chudnovsky , David Fischer , Sepehr Hajebi , Sophie Spirkl , Bartosz Walczak

We investigate topological, combinatorial, statistical, and enumeration properties of finite graphs with high Kolmogorov complexity (almost all graphs) using the novel incompressibility method. Example results are: (i) the mean and variance…

Combinatorics · Mathematics 2007-05-23 Harry Buhrman , Ming Li , John Tromp , Paul Vitanyi

Here, the structural symmetries of a hypergraph are represented through equivalence relations on the vertex set of the hypergraph. A matrix associated with the hypergraph may not reflect a specific structural symmetry. In the context of a…

Combinatorics · Mathematics 2025-08-12 Anirban Banerjee , Samiron Parui

The paper systematically classifies rings based on the dominant metric dimensions (Ddim) of their associated CZDG, establishing consequential bounds for the Ddim of these compressed zero-divisor graphs. The authors investigate the interplay…

Commutative Algebra · Mathematics 2024-05-09 Nasir Ali , Hafiz Muhammad Afzal Siddiqui , Muhammad Imran Qureshi

In 1930, Ramsey proved that every large graph contains either a large clique or a large edgeless graph as an induced subgraph. It is well known that every large connected graph contains a long path, a large clique, or a large star as an…

Combinatorics · Mathematics 2026-04-22 Sarah Allred , M. N. Ellingham

A circle graph is an intersection graph of a set of chords of a circle. We describe the unavoidable induced subgraphs of circle graphs with large treewidth. This includes examples that are far from the `usual suspects'. Our results imply…

Combinatorics · Mathematics 2022-12-23 Robert Hickingbotham , Freddie Illingworth , Bojan Mohar , David R. Wood

One property of networks that has received comparatively little attention is hierarchy, i.e., the property of having vertices that cluster together in groups, which then join to form groups of groups, and so forth, up through all levels of…

Physics and Society · Physics 2008-04-12 Aaron Clauset , Cristopher Moore , M. E. J. Newman

I review the state of the art of the investigation on the structure formation in $f(R)$-gravity based on the Covariant and Gauge Invariant approach to perturbations. A critical analysis of the results, in particular the presence of…

General Relativity and Quantum Cosmology · Physics 2015-05-18 Sante Carloni

For every infinite sequence $\omega=x_1,x_2,...$, with $x_i\in\{0,1\}$, we construct an infinite 4-regular graph $X_{\omega}$. These graphs are precisely the Schreier graphs of the action of a certain self-similar group on the space…

We investigate the structure of subspaces of a Hilbert space that are invariant under unitary representations of a discrete group. We work with square integrable representations, and we show that they are those for which we can construct an…

Functional Analysis · Mathematics 2020-07-09 Davide Barbieri , Eugenio Hernández , Victoria Paternostro

We investigate the property of a spatial graph of having a leveled embedding and characterize the abstract graphs with this property. We show that all leveled embeddings are free and we compare leveled and paneled (also known as flat)…

Combinatorics · Mathematics 2025-09-22 Senja Barthel , Fabio Buccoliero

The Cheeger constant of a graph, or equivalently its coboundary expansion, quantifies the expansion of the graph. This notion assumes an implicit choice of a coefficient group, namely, $\mathbb{F}_2$. In this paper, we study Cheeger-type…

Combinatorics · Mathematics 2025-04-29 Uriya A. First , Tali Kaufman

We study how the problem of observables is fully resolved for background independent theories defined on finite graphs. We argue the correct analogue of coordinate independence is the invariance under changes of graph labels, a kind of…

General Relativity and Quantum Cosmology · Physics 2025-08-05 Emil Broukal , Andrea Di Biagio , Eugenio Bianchi , Marios Christodoulou