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Related papers: Cluster type varieties

200 papers

Globular clusters have long been known to contain large excesses of a variety of objects formed through dynamical processes. The past few years have seen a dramatic increase in our knowledge about these systems.

Astrophysics · Physics 2009-11-13 Thomas J. Maccarone , Christian Knigge

Data clustering is an approach to seek for structure in sets of complex data, i.e., sets of "objects". The main objective is to identify groups of objects which are similar to each other, e.g., for classification. Here, an introduction to…

Data Analysis, Statistics and Probability · Physics 2016-02-17 Alexander K. Hartmann

Cluster analysis methods are used to identify homogeneous subgroups in a data set. In biomedical applications, one frequently applies cluster analysis in order to identify biologically interesting subgroups. In particular, one may wish to…

Methodology · Statistics 2016-09-23 Sheila Gaynor , Eric Bair

We give a complete classification of torsion pairs in the cluster categories associated to tubes of finite rank. The classification is in terms of combinatorial objects called Ptolemy diagrams which already appeared in our earlier work on…

Representation Theory · Mathematics 2014-06-06 Thorsten Holm , Peter Jorgensen , Martin Rubey

This paper invents the notion of torified varieties: A torification of a scheme is a decomposition of the scheme into split tori. A torified variety is a reduced scheme of finite type over $\Z$ that admits a torification. Toric varieties,…

Algebraic Geometry · Mathematics 2013-06-03 Javier López Peña , Oliver Lorscheid

Ideas from the image processing literature have recently motivated a new set of clustering algorithms that rely on the concept of total variation. While these algorithms perform well for bi-partitioning tasks, their recursive extensions…

Machine Learning · Statistics 2013-06-06 Xavier Bresson , Thomas Laurent , David Uminsky , James H. von Brecht

It was recently shown by Gross, Hacking, and Keel that, in the absence of frozen indices, a cluster A-variety with generic coefficients is the universal torsor of the corresponding cluster X-variety with corresponding coefficients. We…

Algebraic Geometry · Mathematics 2018-07-03 Travis Mandel

Affine cluster varieties are covered up to codimension 2 by open algebraic tori. We put forth a general conjecture (based on earlier conversation between Vivek Shende and the last author) characterizing their deep locus, i.e. the complement…

Algebraic Geometry · Mathematics 2024-03-06 Marco Castronovo , Mikhail Gorsky , José Simental , David E Speyer

In this paper, we classify the possible group structures on the set of $R$-valued points of an abelian variety, where $R$ is any real closed field. We make use of a family of abelian varieties that, in effect, allows one to quantify over…

Algebraic Geometry · Mathematics 2023-05-31 Nathanial Lowry

The subject considered in this paper has, at least, three points of interest. Suppose that we have a sequence of one-dimensional analytic varieties in a domain in $\Bbb C^n$. The cluster of this sequence consists from all points in the…

Complex Variables · Mathematics 2009-09-25 Evgeny A. Poletsky

A cluster algebra is a commutative algebra whose structure is decided by a skew-symmetrizable matrix or a quiver. When a skew-symmetrizable matrix is invariant under an action of a finite group and this action is admissible, the folded…

Combinatorics · Mathematics 2022-08-31 Byung Hee An , Eunjeong Lee

Globular clusters provide a unique probe of galaxy formation and evolution. Here I briefly summarize the known observational properties of globular cluster systems. One re-occurring theme is that the globular cluster systems of spirals and…

Astrophysics · Physics 2007-05-23 Duncan A. Forbes

This paper continues the study of cluster algebras initiated in math.RT/0104151. Its main result is the complete classification of the cluster algebras of finite type, i.e., those with finitely many clusters. This classification turns out…

Rings and Algebras · Mathematics 2015-06-26 Sergey Fomin , Andrei Zelevinsky

A Calabi-Yau pair of index one and complexity zero is toric. Furthermore, a Calabi-Yau pair of index one and complexity one is of cluster type. In this article, we study Calabi-Yau pairs of index one and complexity two. We develop machinery…

Algebraic Geometry · Mathematics 2025-08-28 Joaquín Moraga , José Ignacio Yáñez

In this paper, we give a complete classification of cotorsion pairs in a cluster category $\mathscr{C}$ of type $A^\infty_\infty$ via certain configurations of arcs, called $\tau$-compact Ptolemy diagrams, in an infinite strip with marked…

Representation Theory · Mathematics 2017-05-30 Huimin Chang , Yu Zhou , Bin Zhu

The centers of most galaxies in the local universe are occupied by compact, barely resolved sources. Based on their structural properties, position in the fundamental plane, and integrated spectra, these sources clearly have a stellar…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 Torsten Boeker

We define Stasheff polytopes in the space of tropical points of cluster A-varieties. We study the supports of products of elements of canonical bases for cluster X-varieties. We prove that, for the cluster X-variety of type A_n, such…

Algebraic Geometry · Mathematics 2015-11-05 Linhui Shen

Clusters appear in nature in a diversity of contexts, involving distances as long as the cosmological ones, and down to atoms and molecules and the very small nuclear size. They also appear in several other scenarios, in particular in…

Populations and Evolution · Quantitative Biology 2020-02-19 D. Bazeia , M. V. de Moraes , B. F. de Oliveira

Tensors or multiarray data are generalizations of matrices. Tensor clustering has become a very important research topic due to the intrinsically rich structures in real-world multiarray datasets. Subspace clustering based on vectorizing…

Computer Vision and Pattern Recognition · Computer Science 2015-04-30 Yanfeng Sun , Junbin Gao , Xia Hong , Bamdev Mishra , Baocai Yin

We study the relation between the cluster automorphisms and the quasi-automorphisms of a cluster algebra $\mathcal{A}$. We proof that under some mild condition, satisfied for example by every skew-symmetric cluster algebra, the…

Rings and Algebras · Mathematics 2018-08-08 Wen Chang , Ralf Schiffler