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Related papers: Examples of weak amalgamation classes

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We show that semi-infinite cohomology of a finite dimensional graded algebra (satisfying some additional requirements) are a particular case of a general categorical construction. The motivating example is provided by small quantum groups…

Representation Theory · Mathematics 2007-05-23 Roman Bezrukavnikov

We introduce and study asymptotically rigid mapping class groups of certain infinite graphs. We determine their finiteness properties and show that these depend on the number of ends of the underlying graph. In a special case where the…

Geometric Topology · Mathematics 2025-09-01 Thomas Hill , Sanghoon Kwak , Brian Udall , Jeremy West

We study multidimensional diagrams in independent amalgamation in the framework of abstract elementary classes (AECs). We use them to prove the eventual categoricity conjecture for AECs, assuming a large cardinal axiom. More precisely, we…

Logic · Mathematics 2023-03-10 Saharon Shelah , Sebastien Vasey

In this paper, we establish a theorem that proves a condition when an inclusion morphism between simplicial sets becomes a weak homotopy equivalence. Additionally, we present two applications of this result. The first application…

Algebraic Topology · Mathematics 2024-05-07 Hisato Matsukawa

Mapping class groups of locally finite graphs are the analogue of those of infinite-type surfaces, and serve as a "big" version of $\text{Out}(F_n)$. In this paper, we investigate which of these mapping class groups have a dense conjugacy…

Geometric Topology · Mathematics 2026-01-09 Rachmiel Klein

In this paper we introduce a general notion of weak extension property for embeddings induced by a group actions. As an example, for the group H(M, m) of measure-preserving homeomorphisms of a noncompact manifold M, we deduce weak type…

Geometric Topology · Mathematics 2009-04-09 Tatsuhiko Yagasaki

We extend the weak Bruhat order of a finite Coxeter group to the set of its coclasses, modulo parabolic standard subgroups. We use this order to describe associative algebra structures on the vector spaces spanned by the faces of…

Combinatorics · Mathematics 2007-05-23 Patricia Palacios , Maria Ronco

We study classes of right-angled Coxeter groups with respect to the strong submodel relation of parabolic subgroup. We show that the class of all right-angled Coxeter group is not smooth, and establish some general combinatorial criteria…

Logic · Mathematics 2019-12-19 Tapani Hyttinen , Gianluca Paolini

We first give a relative flexible process to construct torsion cohomology classes for Shimura varieties of Kottwitz-Harris-Taylor type with coefficient in a non too regular local system. We then prove that associated to each torsion…

Number Theory · Mathematics 2017-01-03 Pascal Boyer

Call a hereditary family $\mathcal{F}$ of graphs strongly persistent if there exists a graphon $W$ such that in all subgraphons $W'$ of $W$, $\mathcal{F}$ is precisely the class of finite graphs that have positive density in $W'$. Our first…

Combinatorics · Mathematics 2024-07-22 Leonardo N. Coregliano , Maryanthe Malliaris

We prove a version of a small index property theorem for strong amalgamation classes. Our result builds on an earlier theorem by Lascar and Shelah (in their case, for saturated models of uncountable first-order theories). We then study…

Logic · Mathematics 2017-10-10 Zaniar Ghadernezhad , Andrés Villaveces

We study weakly symmetric special biserial algebras of infinite representation type. We show that usually some socle deformation of such an algebra has non-periodic bounded modules. The exceptions are precisely the algebras whose Brauer…

Representation Theory · Mathematics 2016-01-28 Karin Erdmann

We use the characteristic polynomial of the Coxeter matrix of an algebra to complete the combinatorial classification of piecewise hereditary algebras which Happel gave in terms of the trace of the Coxeter matrix. We also give a…

Representation Theory · Mathematics 2009-03-26 Marcelo Lanzilotta , Maria Julia Redondo , Rachel Taillefer

We define two different weakenings of coarse amenability (also known as Yu's property A), namely fibred coarse amenability and coarse amenability at infinity. These two properties allow us to prove that a residually finite group is coarsely…

Group Theory · Mathematics 2019-01-01 Thibault Pillon

A class $\mathcal{G}$ of graphs is called hereditary if it is closed under taking induced subgraphs. We denote by $\mathcal{G}^\mathrm{apex}$ the class of graphs $G$ that contain a vertex $v$ such that $G-v$ is in $\mathcal{G}$. We prove…

Combinatorics · Mathematics 2024-11-27 Jagdeep Singh , Vaidy Sivaraman , Thomas Zaslavsky

In this article, we show that there is no cofibration category structure on the category of finite graphs with $\times$-homotopy equivalences as the class of weak equivalences. Further, we show that it is not possible to enlarge the class…

Algebraic Topology · Mathematics 2023-11-29 Shuchita Goyal , Rekha Santhanam

Noncrossing partition posets in a Coxeter group $W$ can fail to be lattices when $W$ is not finite. When the lattice property fails for $W$ of affine type, McCammond and Sulway's construction provides a larger lattice that contains the…

Representation Theory · Mathematics 2025-10-21 Eric J. Hanson , Nathan Reading

In this paper, we construct various examples of holomorphic laminations, with leaves of dimension 1, and we also study some of their dynamical properties. In particular we study existence and uniqueness of positive closed currents. We…

Dynamical Systems · Mathematics 2010-02-16 John Erik Fornaess , Nessim Sibony , Erlend Fornaess Wold

In this paper, we apply the techniques developed in [5] to present several consequences of studying UMP algebras and the ramifications graph of a monomial bound quiver algebra. Specifically, we prove that every weakly connected component of…

Representation Theory · Mathematics 2025-08-20 Jhony Caranguay-Mainguez , Andrés Franco , David Reynoso-Mercado , Pedro Rizzo

We develop some basic results about full amalgamation classes with intrinsic trascendentals. These classes have generics whose models may have finite subsets whose intrinsic closure is not contained in its algebraic closure. We will show…

Logic · Mathematics 2015-12-15 Justin Brody