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Related papers: A survey on tame abstract elementary classes

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We prove that a universal class categorical in a high-enough cardinal is categorical on a tail of cardinals. As opposed to other results in the literature, we work in ZFC, do not require the categoricity cardinal to be a successor, do not…

Logic · Mathematics 2017-03-28 Sebastien Vasey

Let K be an Abstract Elementary Class. Under the asusmptions that K has a nicely behaved forking-like notion, regular types and existence of some prime models we establish a decomposition theorem for such classes. The decomposition implies…

Logic · Mathematics 2007-05-23 Rami Grossberg , Olivier Lessmann

We deal with stability theory for ``reasonable'' non-elementary classes without any remanents of compactness (like: above Hanf number or definable by L_{omega_1, omega}).

Logic · Mathematics 2007-08-15 Saharon Shelah

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

We give a self-contained introduction to accessible categories and how they shed light on both model- and set-theoretic questions. We survey for example recent developments on the study of presentability ranks, a notion of cardinality…

Category Theory · Mathematics 2020-01-08 Sebastien Vasey

We point out a gap in Shelah's proof of the following result: $\mathbf{Claim}$ Let $K$ be an abstract elementary class categorical in unboundedly many cardinals. Then there exists a cardinal $\lambda$ such that whenever $M, N \in K$ have…

Logic · Mathematics 2015-10-19 Will Boney , Sebastien Vasey

We use orthogonality calculus to prove a downward transfer from categoricity in a successor in abstract elementary classes (AECs) that have a good frame (a forking-like notion for types of singletons) on an interval of cardinals:…

Logic · Mathematics 2016-12-22 Sebastien Vasey

We study the problem of extending an abstract independence notion for types of singletons (what Shelah calls a good frame) to longer types. Working in the framework of tame abstract elementary classes, we show that good frames can always be…

Logic · Mathematics 2018-01-12 Will Boney , Sebastien Vasey

We provide here the first steps toward Classification Theory of Abstract Elementary Classes with no maximal models, plus some mild set theoretical assumptions, when the class is categorical in some lambda greater than its Lowenheim-Skolem…

Logic · Mathematics 2009-09-25 Saharon Shelah , Andrés Villaveces

For an abstract elementary class $\mathbf{K}$ and a cardinal $\lambda \geq LS(\mathbf{K})$, we prove under mild cardinal arithmetic assumptions, categoricity in two succesive cardinals, almost stability for $\lambda^+$-minimal types and…

Logic · Mathematics 2024-09-06 Marcos Mazari-Armida , Sebastien Vasey , Wentao Yang

We compare abstract elementary classes of Shelah with accessible categories having directed colimits.

Category Theory · Mathematics 2013-09-17 Tibor Beke , Jiri Rosicky

We prove a version of Shelah's Categoricity Conjecture for arbitrary deconstructible classes of modules. Moreover, we show that if $\mathcal{A}$ is a deconstructible class of modules that fits in an abstract elementary class…

Representation Theory · Mathematics 2024-10-01 Jan Šaroch , Jan Trlifaj

We show that the condition of being categorical in a tail of cardinals can be characterized algebraically for several classes of modules. $Theorem.$ Assume $R$ is an associative ring with unity. 1. The class of locally pure-injective…

Rings and Algebras · Mathematics 2022-10-11 Marcos Mazari-Armida

Motivated by team semantics and existential second-order logic, we develop a model-theoretic framework for studying second-order objects such as sets and relations. We introduce a notion of abstract elementary team categories that…

Logic · Mathematics 2026-05-08 Tapani Hyttinen , Joni Puljujärvi , Davide Emilio Quadrellaro

We show, assuming a mild set-theoretic hypothesis, that if an abstract elementary class (AEC) has a superstable-like forking notion for models of cardinality $\lambda$ and a superstable-like forking notion for models of cardinality…

Logic · Mathematics 2020-02-28 Sebastien Vasey

We show that metric abstract elementary classes (mAECs) are, in the sense of [LR] (i.e. arXiv:1404.2528), coherent accessible categories with directed colimits, with concrete $\aleph_1$-directed colimits and concrete monomorphisms. More…

Logic · Mathematics 2017-03-30 Michael Lieberman , Jiri Rosicky

Let X be a separated scheme of finite type over an algebraically closed field k and let m be a natural number. By an explicit geometric construction using torsors we construct a pairing between the first mod m Suslin homology and the first…

Algebraic Geometry · Mathematics 2016-01-12 Thomas Geisser , Alexander Schmidt

The assumption that an AEC is tame is a powerful assumption permitting development of stability theory for AECs with the amalgamation property. Lately several upward categoricity theorems were discovered where tameness replaces strong…

Logic · Mathematics 2007-05-23 Rami Grossberg , Alexei S. Kolesnikov

This is an introduction to the study of abstract homotopy theory by means of model categories and $(\infty,1)$-categories. The only prerequisites are very basic general topology and abstract algebra. None categorical background is needed.…

Algebraic Topology · Mathematics 2020-08-13 Yuri Ximenes Martins

We introduce $\mu$-Abstract Elementary Classes ($\mu$-AECs) as a broad framework for model theory that includes complete boolean algebras and Dirichlet series, and begin to develop their classification theory. Moreover, we note that…

Logic · Mathematics 2016-04-27 Will Boney , Rami Grossberg , Michael Lieberman , Jiri Rosicky , Sebastien Vasey