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Related papers: Contraction semigroups on metric graphs

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In this paper we consider endomorphisms of an undirected cycle graph from Semigroup Theory perspective. Our main aim is to present a process to determine sets of generators with minimal cardinality for the monoids $wEnd(C_n)$ and $End(C_n)$…

Rings and Algebras · Mathematics 2023-10-09 Ilinka Dimitrova , Vítor H. Fernandes , Jörg Koppitz , Teresa M. Quinteiro

The dynamics of the left translation semigroup $\{T_t\}_{t \geq 0}$ on weighted $L^p$ spaces over a directed metric tree $L(G)$ is investigated. Necessary and sufficient conditions on the weight family $\rho$ for the strong continuity of…

Functional Analysis · Mathematics 2026-04-28 Elisabetta Mangino , Alvaro Vargas-Moreno

We characterise the respective semigroups of mappings that preserve, or that preserve or reverse orientation of a finite cycle, in terms of their actions on oriented triples and oriented quadruples. This leads to a proof that the latter…

Combinatorics · Mathematics 2022-01-19 Peter M. Higgins , Alexei Vernitski

The paper consists of two parts. In the first one we show that a relatively hyperbolic group $G$ splits as a star graph of groups whose central vertex group is finitely generated and the other vertex groups are maximal parabolic subgroups.…

Group Theory · Mathematics 2015-02-20 Victor Gerasimov , Leonid Potyagailo

Existing approaches to analyzing the asymptotics of graph Laplacians typically assume a well-behaved kernel function with smoothness assumptions. We remove the smoothness assumption and generalize the analysis of graph Laplacians to include…

Machine Learning · Statistics 2011-01-31 Daniel Ting , Ling Huang , Michael Jordan

We develop two generalizations of contraction theory, namely, semi-contraction and weak-contraction theory. First, using the notion of semi-norm, we propose a geometric framework for semi-contraction theory. We introduce matrix…

Systems and Control · Electrical Eng. & Systems 2020-10-06 Saber Jafarpour , Pedro Cisneros-Velarde , Francesco Bullo

Directed graphs have long been used to gain understanding of the structure of semigroups, and recently the structure of directed graph semigroups has been investigated resulting in a characterization theorem and an analog of Fruct's…

Combinatorics · Mathematics 2015-06-09 Tien Chih , Demitri Plessas

We investigate subsets of the symmetric group with structure similar to that of a graph. The trees of these subsets correspond to minimal conjugate generating sets of the symmetric group. There are two main theorems in this paper. The first…

Combinatorics · Mathematics 2007-11-21 Jacob Steinhardt

The aim of this paper is to see how commuting graphs interact with two semigroup constructions: the zero-union and the direct product. For both semigroup constructions, we investigate the diameter, clique number, girth, chromatic number and…

Combinatorics · Mathematics 2025-11-06 Tânia Paulista

We consider the space-fractional operator with order $0<\alpha<1$ on the metric star graph. The boundary conditions at the vertices of the metric star graph providing the self-adjointness of the operator are derived. The obtained result is…

Spectral Theory · Mathematics 2023-05-03 K. K. Sabirov , R. R. Ashurov

Signed graphs have appeared in a broad variety of applications, ranging from social networks to biological networks, from distributed control and computation to power systems. In this paper, we investigate spectral properties of signed…

Systems and Control · Electrical Eng. & Systems 2020-09-09 Wei Chen , Dan Wang , Ji Liu , Yongxin Chen , Sei Zhen Khong , Tamer Başar , Karl H. Johansson , Li Qiu

This paper is to study some conditions on semigroups, generated by some class of non-densely defined operators in the closure of its domain, in order that certain bounded perturbations preserve some regularity properties of the semigroup…

Functional Analysis · Mathematics 2019-09-26 Deliang Chen

Succinct representations of a graph have been objects of central study in computer science for decades. In this paper, we study the operation called \emph{Distance Preserving Graph Contractions}, which was introduced by Bernstein et al.…

Computational Complexity · Computer Science 2019-12-03 Siddhartha Jain

The general ideal of this paper is to answer the following question: given a numerical property of commuting graphs, a class of semigroups $\mathcal{C}$ and $n\in\mathbb{N}$, is it possible to find a semigroup in $\mathcal{C}$ such that the…

Group Theory · Mathematics 2025-11-14 Tânia Paulista

In the field of complex networks and graph theory, new results are typically tested on graphs generated by a variety of algorithms such as the Erd\H{o}s-R\'{e}nyi model or the Barab\'{a}si-Albert model. Unfortunately, most graph generating…

Combinatorics · Mathematics 2018-08-16 Isaac Klickstein , Francesco Sorrentino

We consider diffusion processes on metric graphs with semipermeable sticky membranes in each vertex. We prove that the process is governed by a Feller semigroup and find its asymptotic behavior as diffusion's speed increases to infinity…

Probability · Mathematics 2022-01-25 Adam Gregosiewicz

Sampling is a widely used graph reduction technique to accelerate graph computations and simplify graph visualizations. By comprehensively analyzing the literature on graph sampling, we assume that existing algorithms cannot effectively…

Social and Information Networks · Computer Science 2020-09-17 Ying Zhao , Haojin Jiang , Qi'an Chen , Yaqi Qin , Huixuan Xie , Yitao Wu Shixia Liu , Zhiguang Zhou , Jiazhi Xia , Fangfang Zhou

We consider the actions of (semi)groups on a locally compact group by automorphisms. We show the equivalence of distality and pointwise distality for the actions of a certain class of groups. We also show that a compactly generated locally…

Dynamical Systems · Mathematics 2019-03-27 C. R. E. Raja , Riddhi Shah

We consider semigroups of continuous, surjective, locally injective maps of a compact metric space, and whether such semigroups admit a transfer operator.

Dynamical Systems · Mathematics 2010-07-15 Justin R. Peters

Some concepts, such as non-compactness measure and condensing operators, defined on metric spaces are extended to uniform spaces. Such extensions allow us to locate, in the context of uniform spaces, some classical results existing in…

General Topology · Mathematics 2015-11-25 Raúl Fierro