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We link the recent theory of $L$-algebras to previous notions of Universal Algebra and Categorical Algebra concerning subtractive varieties, commutators, multiplicative lattices, and their spectra. We show that the category of $L$-algebras…

Category Theory · Mathematics 2023-05-31 Alberto Facchini , Marino Gran , Mara Pompili

We find the model completion of the theory modules over $A$, where $A$ is a finitely generated commutative algebra over a field $K$. This is done in a context where the field $K$ and the module are represented by sorts in the theory, so…

Logic · Mathematics 2009-08-05 Moshe Kamensky

We exhibit a theory where definable types lack the amalgamation property.

Logic · Mathematics 2025-03-14 Martin Hils , Rosario Mennuni

For every natural number $m$, the existentially closed models of the theory of fields with $m$ commuting derivations can be given a first-order geometric characterization in several ways. In particular, the theory of these differential…

Logic · Mathematics 2013-01-04 David Pierce

Models of dependent type theories are contextual categories with some additional structure. We prove that if a theory $T$ has enough structure, then the category $T\text{-}\mathbf{Mod}$ of its models carries the structure of a model…

Category Theory · Mathematics 2016-07-26 Valery Isaev

The idea of this paper is to explore the existence of canonical countably saturated models for different classes of structures. It is well-known that, under CH, there exists a unique countably saturated linear order of cardinality…

Logic · Mathematics 2020-04-17 Ziemowit Kostana

We show that the discrete anomaly constraints governing popular non-Abelian symmetries of use in (e.g.) flavoured, supersymmetric, and dark matter model building typically subdivide into two classes differentiated by the simple restrictions…

High Energy Physics - Phenomenology · Physics 2018-11-15 Jim Talbert

Arbitrarily many pairwise inequivalent modular categories can share the same modular data. We exhibit a family of examples that are module categories over twisted Drinfeld doubles of finite groups, and thus in particular integral modular…

Quantum Algebra · Mathematics 2021-06-09 Michaël Mignard , Peter Schauenburg

It is proved that a multiset of permissible arcs over a tiling is uniquely determined by its intersection vector under a mild condition. This generalizes a classical result over marked surfaces with triangulations. We apply this result to…

Representation Theory · Mathematics 2023-10-06 Changjian Fu , Shengfei Geng

For a given cluster-tilted algebra $A$ of tame type, it is proved that different indecomposable $\tau$-rigid $A$-modules have different dimension vectors. This is motivated by Fomin-Zelevinsky's denominator conjecture for cluster algebras.…

Rings and Algebras · Mathematics 2024-02-15 Changjian Fu , Shengfei Geng

Bartholdi and Smoktunowicz constructed finitely generated monomial algebras with prescribed sufficiently fast growth types. We show that their construction need not result in a prime algebra, but it can be modified to provide prime algebras…

Rings and Algebras · Mathematics 2017-07-03 Be'eri Greenfeld

We show that bounded type implies finite type for a constructible subcategory of the module category of a finitely generated algebra over a field, which is a variant of the first Brauer-Thrall conjecture. A full subcategory is constructible…

Representation Theory · Mathematics 2025-07-31 Kevin Schlegel , Andres Fernandez Herrero

We give a combinatorial equivalent to the existence of a non-free hereditarily separable group of cardinality aleph_1. This can be used, together with a known combinatorial equivalent of the existence of a non-free Whitehead group, to prove…

Logic · Mathematics 2007-05-23 Paul C. Eklof , Alan H. Mekler , Saharon Shelah

Shumyatsky and the second author proved that if G is a finitely generated residually finite p-group satisfying a law, then, for almost all primes, the fact that a normal and commutator-closed set of generators satisfies a positive law…

Group Theory · Mathematics 2011-08-04 C. Acciarri , G. A. Fernández-Alcober

We show that the following two theories are equiconsistent: (T) ZFC, CH and "There is a dense ideal on the first uncountable cardinal such that if j is the generic embedding associated with it then its restriction on ordinals is independent…

Logic · Mathematics 2022-09-21 Dominik Adolf , Grigor Sargsyan , Nam Trang , Trevor Wilson , Martin Zeman

The Kuchar observables notion is shown to apply only to a limited range of theories. Relational mechanics, slightly inhomogeneous cosmology and supergravity are used as examples that require further notions of observables. A suitably…

General Relativity and Quantum Cosmology · Physics 2016-04-20 Edward Anderson

We study bounded width algebras which are minimal in the sense that every proper reduct does not have bounded width. We show that minimal bounded width algebras can be arranged into a pseudovariety with one basic ternary operation. We…

Rings and Algebras · Mathematics 2020-02-17 Zarathustra Brady

Individual choices often depend on the order in which the decisions are made. In this paper, we expose a general theory of measurable systems (an example of which is an individual's preferences) allowing for incompatible (non-commuting)…

Physics and Society · Physics 2007-06-20 V. I. Danilov , A. Lambert-Mogiliansky

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

By the Telescope Conjecture for Module Categories, we mean the following claim: "Let R be any ring and (A, B) be a hereditary cotorsion pair in Mod-R with A and B closed under direct limits. Then (A, B) is of finite type." We prove a…

Rings and Algebras · Mathematics 2008-09-16 Jan Saroch , Jan Stovicek