English
Related papers

Related papers: A Cambrian framework for the oriented cycle

200 papers

We give a combinatorial model for the exchange graph and g-vector fan associated to any acyclic exchange matrix B of affine type. More specifically, we construct a reflection framework for B in the sense of [N. Reading and D. E. Speyer,…

Combinatorics · Mathematics 2026-05-13 Nathan Reading , David E. Speyer

We develop a general approach to finding combinatorial models for cluster algebras. The approach is to construct a labeled graph called a framework. When a framework is constructed with certain properties, the result is a model…

Combinatorics · Mathematics 2026-05-28 Nathan Reading , David E Speyer

In a series of previous papers, we studied sortable elements in finite Coxeter groups, and the related Cambrian fans. We applied sortable elements and Cambrian fans to the study of cluster algebras of finite type and the noncrossing…

Combinatorics · Mathematics 2026-05-13 Nathan Reading , David E Speyer

We apply convex geometry (cones, fans) to homological input (abelian categories, hearts of bounded t-structures) to construct a new invariant of an abelian category, its heart fan. This can be viewed as a `universal phase diagram' for…

Representation Theory · Mathematics 2024-09-06 Nathan Broomhead , David Pauksztello , David Ploog , Jon Woolf

In this chapter, we trace the path from the Tamari lattice, via lattice congruences of the weak order, to the definition of Cambrian lattices in the context of finite Coxeter groups, and onward to the construction of Cambrian fans. We then…

Combinatorics · Mathematics 2026-05-13 Nathan Reading

For an arbitrary finite Coxeter group W we define the family of Cambrian lattices for W as quotients of the weak order on W with respect to certain lattice congruences. We associate to each Cambrian lattice a complete fan, which we…

Combinatorics · Mathematics 2026-05-13 Nathan Reading

For a finite Coxeter group W and a Coxeter element c of W, the c-Cambrian fan is a coarsening of the fan defined by the reflecting hyperplanes of W. Its maximal cones are naturally indexed by the c-sortable elements of W. The main result of…

Combinatorics · Mathematics 2026-05-13 Nathan Reading , David E Speyer

We give an explicit construction of the cluster scattering diagram for any acyclic exchange matrix of affine type. We show that the corresponding cluster scattering fan coincides both with the mutation fan and with a fan constructed in the…

Combinatorics · Mathematics 2025-08-04 Nathan Reading , Salvatore Stella

For each finite real reflection group $W$, we identify a copy of the type-$W$ simplicial generalised associahedron inside the corresponding simplicial permutahedron. This defines a bijection between the facets of the generalised…

Combinatorics · Mathematics 2008-04-16 Thomas Brady , Colum Watt

We generalize the combinatorial description of the orbifold (Chen--Ruan) cohomology and of the Grothendieck ring of a Deligne--Mumford toric stack and its associated stacky fan in a lattice $N$ in the presence of a deformation parameter…

Algebraic Geometry · Mathematics 2017-08-23 R. Paul Horja

Given a finite Coxeter system $(W,S)$ and a Coxeter element $c$, we construct a simple polytope whose outer normal fan is N. Reading's Cambrian fan $F_c$, settling a conjecture of Reading that this is possible. We call this polytope the…

Combinatorics · Mathematics 2011-12-20 Christophe Hohlweg , Carsten Lange , Hugh Thomas

These are notes on the construction of the GIT-fans for quivers without oriented cycles. We follow closely the steps outlined by N. Ressayre in "The GIT-Equivalence for G-Line Bundles" (Geometriae Dedicata, Volume 81, Numbers 1-3, 2000). A…

Representation Theory · Mathematics 2008-05-13 Calin Chindris

Scattering diagrams arose in the context of mirror symmetry, but a special class of scattering diagrams (the cluster scattering diagrams) were recently developed to prove key structural results on cluster algebras. We use the connection to…

Combinatorics · Mathematics 2026-05-21 Nathan Reading

This is a sequel to the second and third author's Mixed Dimer Configuration Model in Type $D$ Cluster Algebras where we extend our model to work for quivers that contain oriented cycles. Namely, we extend a combinatorial model for…

Combinatorics · Mathematics 2022-11-17 Libby Farrell , Gregg Musiker , Kayla Wright

This paper shows the polytopality of any finite type $\mathbf{g}$-vector fan, acyclic or not. In fact, for any finite Dynkin type $\Gamma$, we construct a universal associahedron $\mathsf{Asso}_{\mathrm{un}}(\Gamma)$ with the property that…

Combinatorics · Mathematics 2023-11-14 Christophe Hohlweg , Vincent Pilaud , Salvatore Stella

Scattering diagrams arose in the context of mirror symmetry, Donaldson-Thomas theory, and integrable systems. We show that a consistent scattering diagram with minimal support cuts the ambient space into a complete fan. A special class of…

Combinatorics · Mathematics 2026-05-13 Nathan Reading

This paper addresses the problem of constructing a cycle-level intersection theory for toric varieties. We show that by making one global choice, we can determine a cycle representative for the intersection of an equivariant Cartier divisor…

Algebraic Geometry · Mathematics 2007-05-23 Hugh Thomas

Given a quiver, a fixed dimension vector, and a positive integer n, we construct a functor from the category of D-modules on the space of representations of the quiver to the category of modules over a corresponding Gan-Ginzburg algebra of…

Representation Theory · Mathematics 2010-05-18 Silvia Montarani

We present a new method for combining two cotorsion pairs to obtain an abelian model structure and we apply it to construct and study a new model structure on left $R$-modules over a left coherent ring $R$. Its class of fibrant objects is…

Rings and Algebras · Mathematics 2026-02-11 James Gillespie

We develop a combinatorial model of networks on orientable surfaces, and study weight and homology generating functions of paths and cycles in these networks. Network transformations preserving these generating functions are investigated.…

Combinatorics · Mathematics 2010-08-12 Thomas Lam , Pavlo Pylyavskyy
‹ Prev 1 2 3 10 Next ›