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Related papers: Cluster algebras and triangulated orbifolds

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This thesis is concerned with studying the properties of gradings on several examples of cluster algebras, primarily of infinite type. We first consider two finite type cases: $B_n$ and $C_n$, completing a classification by Grabowski for…

Representation Theory · Mathematics 2018-03-07 Thomas Booker-Price

Cluster ensemble is a pair of positive spaces (X, A) related by a map p: A -> X. It generalizes cluster algebras of Fomin and Zelevinsky, which are related to the A-space. We develope general properties of cluster ensembles, including its…

Algebraic Geometry · Mathematics 2009-08-04 V. V. Fock , A. B. Goncharov

Cluster automorphisms have been shown to have links to the mapping class groups of surfaces, maximal green sequences and to exchange graph automorphisms for skew-symmetric cluster algebras. In this paper we aim to generalise these results…

Combinatorics · Mathematics 2016-12-12 John W. Lawson

Convex clustering is an attractive clustering algorithm with favorable properties such as efficiency and optimality owing to its convex formulation. It is thought to generalize both k-means clustering and agglomerative clustering. However,…

Machine Learning · Statistics 2021-05-19 Canh Hao Nguyen , Hiroshi Mamitsuka

We provide an explicit Dynkin diagrammatic description of the c-vectors and the d-vectors (the denominator vectors) of any cluster algebra of finite type with principal coefficients and any initial exchange matrix. We use the surface…

Rings and Algebras · Mathematics 2014-01-14 Tomoki Nakanishi , Salvatore Stella

A general theory of permutation orbifolds is developed for arbitrary twist groups. Explicit expressions for the number of primaries, the partition function, the genus one characters, the matrix elements of modular transformations and for…

High Energy Physics - Theory · Physics 2009-10-31 P. Bantay

The aim of the paper is to define noncommutative cluster structure on several algebras ${\mathcal A}$ related to marked surfaces possibly with orbifold points of various orders, which includes noncommutative clusters, i.e., embeddings of a…

Representation Theory · Mathematics 2025-08-14 Arkady Berenstein , Min Huang , Vladimir Retakh

This manuscript develops the theory of agglomerative clustering with Bregman divergences. Geometric smoothing techniques are developed to deal with degenerate clusters. To allow for cluster models based on exponential families with…

Machine Learning · Computer Science 2012-07-03 Matus Telgarsky , Sanjoy Dasgupta

We study the $c$-vectors, $g$-vectors, and $F$-polynomials for generalized cluster algebras satisfying a normalization condition and a power condition recovering classical recursions and separation of additions formulas. We establish a…

Rings and Algebras · Mathematics 2018-06-06 Tomoki Nakanishi , Dylan Rupel

In this manuscript, we study the statistical properties of convex clustering. We establish that convex clustering is closely related to single linkage hierarchical clustering and $k$-means clustering. In addition, we derive the range of…

Methodology · Statistics 2015-09-15 Kean Ming Tan , Daniela Witten

Cluster algebras were introduced by S. Fomin and A. Zelevinsky in connection with dual canonical bases. Let U be a cluster algebra of type A_n. We associate to each cluster C of U an abelian category Cat_C such that the indecomposable…

Representation Theory · Mathematics 2014-04-09 Philippe Caldero , Frederic Chapoton , Ralf Schiffler

The article gives a ring theoretic perspective on cluster algebras. Gei{\ss}-Leclerc-Schr\"oer prove that all cluster variables in a cluster algebra are irreducible elements. Furthermore, they provide two necessary conditions for a cluster…

Rings and Algebras · Mathematics 2012-10-05 Philipp Lampe

For a rooted cluster algebra $\mathcal{A}(Q)$ over a valued quiver $Q$, a \emph{symmetric cluster variable} is any cluster variable belonging to a cluster associated with a quiver $\sigma (Q)$, for some permutation $\sigma$. The subalgebra…

Representation Theory · Mathematics 2024-03-08 Ibrahim Saleh

We prove that in a 2-Calabi-Yau triangulated category, each cluster tilting subcategory is Gorenstein with all its finitely generated projectives of injective dimension at most one. We show that the stable category of its Cohen-Macaulay…

Representation Theory · Mathematics 2007-05-23 Bernhard Keller , Idun Reiten

We consider triangulated orbit categories, with the motivating example of cluster categories, in their usual context of algebraic triangulated categories, then present them from another perspective in the framework of topological…

Algebraic Topology · Mathematics 2014-11-14 Julia E. Bergner , Marcy Robertson

In our previous paper we have discussed Poisson properties of cluster algebras of geometric type for the case of a nondegenerate matrix of transition exponents. In this paper we consider the case of a general matrix of transition exponents.…

Quantum Algebra · Mathematics 2007-05-23 Michael Gekhtman , Michael Shapiro , Alek Vainshtein

Let $G$ be a simply connected simple algebraic group over $\mathbb{C}$, $B$ and $B_-$ be its two opposite Borel subgroups. For two elements $u$, $v$ of the Weyl group $W$, it is known that the coordinate ring ${\mathbb C}[G^{u,v}]$ of the…

Quantum Algebra · Mathematics 2017-04-12 Yuki Kanakubo , Toshiki Nakashima

In this paper a novel possibilistic c-means clustering algorithm, called Adaptive Possibilistic c-means, is presented. Its main feature is that {\it all} its parameters, after their initialization, are properly adapted during its execution.…

Computer Vision and Pattern Recognition · Computer Science 2015-10-16 Spyridoula D. Xenaki , Konstantinos D. Koutroumbas , Athanasios A. Rontogiannis

Let $S$ be an upper cluster algebra, which is a subalgebra of $R$. Suppose that there is some cluster variable $x_e$ such that ${R}_{{x}_e} = S[{x}_e^{\pm 1}]$. We try to understand under which conditions ${R}$ is an upper cluster algebra,…

Commutative Algebra · Mathematics 2017-07-18 Jiarui Fei , Jerzy Weyman

A family of quantum cluster algebras is introduced and studied. In general, these algebras are new, but subclasses have been studied previously by other authors. The algebras are indexed by double partitions or double flag varieties.…

Quantum Algebra · Mathematics 2012-10-09 Hans Plesner Jakobsen , Hechun Zhang