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Related papers: Cluster structures in mixed Grassmanianns

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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 document we present a twistor correspondence for half-flat almost-Grassmannian structures on real and complex manifolds. We provide foundational results regarding local theory in the complex setting and a global correspondence when…

Differential Geometry · Mathematics 2023-04-18 Matthew Lam

We have examined the spatial distribution of substructure in clusters of galaxies using Einstein X-ray observations. Subclusters are found to have a markedly anisotropic distribution that reflects the surrounding matter distribution on…

Astrophysics · Physics 2009-10-28 Michael J. West , Christine Jones , William Forman

This is an introduction to some aspects of Fomin-Zelevinsky's cluster algebras and their links with the representation theory of quivers and with Calabi-Yau triangulated categories. It is based on lectures given by the author at summer…

Representation Theory · Mathematics 2010-03-23 Bernhard Keller

A general framework for dealing with both linear regression and clustering problems is described. It includes Gaussian clusterwise linear regression analysis with random covariates and cluster analysis via Gaussian mixture models with…

Methodology · Statistics 2015-10-13 Giuliano Galimberti , Annamaria Manisi , Gabriele Soffritti

In 2003, Fomin and Zelevinsky obtained Cartan-Killing type classification of all cluster algebras of finite type, i.e. cluster algebras having only finitely many distinct cluster variables. A wider class of cluster algebras is formed by…

Combinatorics · Mathematics 2019-10-25 Anna Felikson , Michael Shapiro , Pavel Tumarkin

We give a construction of generalized cluster varieties and generalized cluster scattering diagrams for reciprocal generalized cluster algebras, the latter of which were defined by Chekhov and Shapiro. These constructions are analogous to…

Combinatorics · Mathematics 2022-11-29 Man-Wai Mandy Cheung , Elizabeth Kelley , Gregg Musiker

The cluster-tilted algebras have been introduced by Buan, Marsh and Reiten, they are the endomorphism rings of cluster-tilting objects $T$ in cluster categories; we call such an algebra cluster-concealed in case $T$ is obtained from a…

Representation Theory · Mathematics 2009-12-31 Claus Michael Ringel

The paper is motivated by an analogy between cluster algebras and Kac-Moody algebras: both theories share the same classification of finite type objects by familiar Cartan-Killing types. However the underlying combinatorics beyond the two…

Combinatorics · Mathematics 2019-03-05 Michael Barot , Christof Geiss , Andrei Zelevinsky

Nakaoka and Palu introduced the notion of extriangulated categories by extracting the similarities between exact categories and triangulated categories. In this paper, we study cotorsion pairs in a Frobenius extriangulated category $\C$.…

Representation Theory · Mathematics 2018-07-20 Wen Chang , Panyue Zhou , Bin Zhu

We introduce triple crossing diagram (TCD) maps, which encode projective configurations of points and lines, as a unified framework for constructions arising in various areas of geometry, such as discrete differential geometry, discrete…

Combinatorics · Mathematics 2026-01-15 Niklas Affolter , Terrence George , Max Glick , Sanjay Ramassamy

The cluster analysis of very large objects is an important problem, which spans several theoretical as well as applied branches of mathematics and computer science. Here we suggest a novel approach: under assumption of local convergence of…

Combinatorics · Mathematics 2015-10-28 Jaroslav Nesetril , Patrice Ossona de Mendez

We define and study a class of finite topological spaces, which model the cell structure of a space obtained by gluing finitely many Euclidean convex polyhedral cells along congruent faces. We call these finite topological spaces,…

Algebraic Topology · Mathematics 2008-07-28 Tathagata Basak

Cluster categories were introduced in 2006 by Buan-Marsh-Reineke-Reiten-Todorov in order to categorify acyclic cluster algebras without coefficients. Their construction was generalized by Amiot (2009) and Plamondon (2011) to arbitrary…

Representation Theory · Mathematics 2023-04-11 Yilin Wu

The purpose of this article is to shed new light on the combinatorial structure of Kazhdan-Lusztig cells in infinite Coxeter groups $W$. Our main focus is the set $\D$ of distinguished involutions in $W$, which was introduced by Lusztig in…

Representation Theory · Mathematics 2014-06-16 Mikhail V. Belolipetsky , Paul E. Gunnells

We establish certain fundamental properties of $f$-vectors and $F$-matrices for generalized cluster algebras, including the initial and final seed mutation formulas, the compatibility property and the symmetry property. Along the way, we…

Rings and Algebras · Mathematics 2025-06-03 Huihui Ye , Changjian Fu

I review recent progress in the study of the large-scale structure of the Universe through the distribution of clusters of galaxies, concentrating on new results using X-ray selected samples. After discussing the importance of understanding…

Astrophysics · Physics 2007-05-23 L. Guzzo

In this paper, we introduce a notion of unistructural cluster algebras, for which the set of cluster variables uniquely determines the clusters. We prove that cluster algebras of Dynkin type and cluster algebras of rank 2 are unistructural,…

Representation Theory · Mathematics 2013-07-19 Ibrahim Assem , Ralf Schiffler , Vasilisa Shramchenko

Matrices are two-dimensional data structures allowing one to conceptually organize information. For example, adjacency matrices are useful to store the links of a network; correlation matrices are simple ways to arrange gene co-expression…

Disordered Systems and Neural Networks · Physics 2022-09-29 Flaviano Morone

We construct affine spaces, projective spaces and grassmannians in the ca\-te\-gory of ringed spaces. We show how finite posets and sheaves of rings on them appear in a natural way.

Algebraic Geometry · Mathematics 2021-01-07 J. Sánchez González , F. Sancho de Salas