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Related papers: On the cluster structures in Collatz level sets

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We describe a framework for encoding cluster combinatorics using categorical methods. We give a definition of an abstract cluster structure, which captures the essence of cluster mutation at a tropical level and show that cluster algebras,…

Rings and Algebras · Mathematics 2025-10-06 Jan E. Grabowski , Sira Gratz

A cluster algebra is unistructural if the set of its cluster variables determines its clusters and seeds. It is conjectured that all cluster algebras are unistructural. In this paper, we show that any cluster algebra arising from a…

Representation Theory · Mathematics 2019-10-23 Véronique Bazier-Matte , Pierre-Guy Plamondon

For a density $f$ on ${\mathbb R}^d$, a {\it high-density cluster} is any connected component of $\{x: f(x) \geq \lambda\}$, for some $\lambda > 0$. The set of all high-density clusters forms a hierarchy called the {\it cluster tree} of…

Machine Learning · Statistics 2014-06-09 Kamalika Chaudhuri , Sanjoy Dasgupta , Samory Kpotufe , Ulrike von Luxburg

The structural, electronic and magnetic properties of Co$_n$ clusters ($n=2-$20) have been investigated using density functional theory within the pseudopotential plane wave method. An unusual hexagonal growth pattern has been observed in…

Atomic and Molecular Clusters · Physics 2015-05-13 S. Datta , M. Kabir , S. Ganguly , B. Sanyal , T. Saha-Dasgupta , A. Mookerjee

The article concerns the existence and uniqueness of quantisations of cluster algebras. We prove that cluster algebras with an initial exchange matrix of full rank admit a quantisation in the sense of Berenstein-Zelevinsky and give an…

Quantum Algebra · Mathematics 2017-09-11 Florian Gellert , Philipp Lampe

In the framework of the planar restricted three body problem we study a considerable number of resonances associated to the Kuiper Belt dynamics and located between 30 and 48 a.u. Our study is based on the computation of resonant periodic…

Astrophysics · Physics 2015-06-24 George Voyatzis , Thomas Kotoulas

I show here that there are three different kinds of iterations for the reduced Collatz algorithm; depending on whether the root of the number is odd or even. There is only one kind of iteration if the root is odd and two kinds if the root…

General Mathematics · Mathematics 2022-10-28 Leonel Sternberg

Let $K$ be an algebraic function field of one variable with constant field $k$ and let $C$ be the Dedekind domain consisting of all those elements of $K$ which are integral outside a fixed place $\infty$ of $K$. When $k$ is finite the group…

Group Theory · Mathematics 2013-12-03 A. W. Mason , Andreas Schweizer

In a previous article, we reduced the unsolved problem of the convergence of Collatz sequences, to convergence of Collatz sequences of odd numbers, that are divisible by 3. In this article, we further reduce this set to odd numbers that are…

Combinatorics · Mathematics 2020-01-07 Maya Mohsin Ahmed

Consider the poset of partitions of {1,...(n-1)k+1} with block sizes congruent to 1 modulo k. We prove that its order complex is a subdivision of the complex of k-trees, thereby answering a question posed by Feichtner. The result is…

Combinatorics · Mathematics 2007-05-23 Emanuele Delucchi

The Collatz iteration is governed by two distinct update rules, depending on the parity of the current iterate: n(i+1)=3n(i)+1 for odd n(i), and n(i+1)=n(i)/2 for even n(i). We show that these rules can be written equivalently as a single…

Dynamical Systems · Mathematics 2026-04-23 Katharina Lodders

As a first step towards a comprehensive investigation of stellar motions within globular clusters, we present here the results of a study of stellar orbits in a mildly triaxial globular cluster that follows a circular orbit inside a galaxy.…

Astrophysics · Physics 2009-10-31 D. D. Carpintero , J. C. Muzzio , F. C. Wachlin

As Collatz conjecture is still to be proved, a method to arrive at the complete proof is explored here. Conceptually, the process relies on the pre-proven sequence data and the method follows the confirmation of the convergence of the…

General Mathematics · Mathematics 2021-03-05 Ramachandra Bhat

Characteristic properties of corings with a grouplike element are analysed. Associated differential graded rings are studied. A correspondence between categories of comodules and flat connections is established. A generalisation of the…

Rings and Algebras · Mathematics 2007-05-23 Tomasz Brzezinski

We consider Beta$(2-\alpha, \alpha)$-coalescents with parameter range $1 <\alpha<2$ starting from $n$ leaves. The length $\ell^{(n)}_r$ of order $r$ in the $n$-Beta$(2-\alpha, \alpha)$-coalescent tree is defined as the sum of the lengths of…

Probability · Mathematics 2022-11-30 Matthias Birkner , Iulia Dahmer , Christina S. Diehl , Götz Kersting

By virtue of their high galaxy space densities and their large spatial separations, clusters are efficient and accurate tracers of the large-scale density and velocity fields. Substantial progress has been made over the past decade in the…

Astrophysics · Physics 2007-05-23 Marc Postman

This Article presents a nonequilibrium thermodynamic theory for the mean-field precipitation, aggregation and pattern formation of colloidal clusters. A variable gradient energy coefficient and the arrest of particle diffusion upon…

Soft Condensed Matter · Physics 2018-10-17 Thomas Petersen , Martin Z. Bazant , Roland J. M. Pellenq , Franz-Josef Ulm

Concave compositions are ordered partitions whose parts are decreasing towards a central part. We study the distribution modulo $a$ of the number of concave compositions. Let $c(n)$ be the number of concave compositions of $n$ having even…

Number Theory · Mathematics 2014-07-07 Keenan Monks , Lynnelle Ye

Rotating clusters or vortices are formations of agents that rotate around a common center. These patterns may be found in very different contexts: from swirling fish to surveillance drones. Here, we propose a minimal model for…

Adaptation and Self-Organizing Systems · Physics 2023-05-16 Julia Cantisán , Jesús M. Seoane , Miguel A. F. Sanjuán

A popular method for selecting the number of clusters is based on stability arguments: one chooses the number of clusters such that the corresponding clustering results are "most stable". In recent years, a series of papers has analyzed the…

Machine Learning · Statistics 2010-07-08 Ulrike von Luxburg