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Related papers: NIP omega-categorical structures: the rank 1 case

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Constructions are given of Noetherian maximal orders that are finitely presented algebras over a field K, defined by monomial relations. In order to do this, it is shown that the underlying homogeneous information determines the algebraic…

Rings and Algebras · Mathematics 2007-11-05 Isabel Goffa , Eric Jespers , Jan Okninski

We prove that any odd-dimensional modular category of rank at most 23 is pointed. We also show that an odd-dimensional modular category of rank 25 is either pointed, perfect, or equivalent to $\operatorname{Rep}(D^\omega(\mathbb Z_7\rtimes…

Quantum Algebra · Mathematics 2023-11-01 Agustina Czenky , William Gvozdjak , Julia Plavnik

If $G$ is a group of permutations of a set $\Omega$ and $\alpha \in \Omega$, then the {\em $\alpha$-suborbits} of $G$ are the orbits of the stabilizer $G_\alpha$ on $\Omega$. The cardinality of an $\alpha$-suborbit is called a {\em…

Group Theory · Mathematics 2012-01-05 Simon M. Smith

We consider three forms of composition of matroids, each of which extends the category of bimatroids to a rigid monoidal category. Many well-known constructions are functorial or defined by morphisms in these categories. Motivating examples…

Combinatorics · Mathematics 2024-03-07 Kevin Purbhoo

Ordered, linear, and other substructural type systems allow us to expose deep properties of programs at the syntactic level of types. In this paper, we develop a family of unary logical relations that allow us to prove consequences of…

Logic in Computer Science · Computer Science 2025-03-06 C. B. Aberlé , Chris Martens , Frank Pfenning

An intermediate stage in Hrushovski's construction of flat strongly minimal structures in a relational language L produces omega-stable structures of rank omega. We analyze the pregeometries given by forking on the regular type of rank…

Logic · Mathematics 2011-03-21 David M. Evans , Marco S. Ferreira

The study of classes of models of a finite diagram was initiated by S. Shelah in 1969. A diagram D is a set of types over the empty set, and the class of models of the diagram D consists of the models of T which omit all the types not in D.…

Logic · Mathematics 2016-09-07 Olivier Lessmann

The groups whose orders factorise into at most four primes have been described (up to isomorphism) in various papers. Given such an order n, this paper exhibits a new explicit and compact determination of the isomorphism types of the groups…

Group Theory · Mathematics 2022-02-23 Heiko Dietrich , Bettina Eick , Xueyu Pan

We develop a theory of k-partitions of the set of infinite words recognizable by classes of finite automata. The theory enables to complete proofs of existing results about topological classifications of the (aperiodic) omega-regular…

Combinatorics · Mathematics 2021-04-22 Victor Selivanov

We show that for any type in Martin-L\"of Intensional Type Theory, the terms of that type and its higher identity types form a weak omega-category in the sense of Leinster. Precisely, we construct a contractible globular operad of definable…

Logic · Mathematics 2015-07-01 Peter LeFanu Lumsdaine

The feasibility of a classification-by-rank program for modular categories follows from the Rank-Finiteness Theorem. We develop arithmetic, representation theoretic and algebraic methods for classifying modular categories by rank. As an…

Quantum Algebra · Mathematics 2016-03-23 Paul Bruillard , Siu-Hung Ng , Eric C. Rowell , Zhenghan Wang

Classification theory of elementary classes deals with first order (elementary) classes of structures (i.e. fixing a set T of first order sentences, we investigate the class of models of T with the elementary submodel notion). It tries to…

Logic · Mathematics 2009-03-23 Saharon Shelah

We present an example of two countable $\omega$-categorical structures, one of which has a finite relational language, whose endomorphism monoids are isomorphic as abstract monoids, but not as topological monoids -- in other words, no…

Logic · Mathematics 2016-07-04 Manuel Bodirsky , David Evans , Michael Kompatscher , Michael Pinsker

A relational structure is a core, if all its endomorphisms are embeddings. This notion is important for computational complexity classification of constraint satisfaction problems. It is a fundamental fact that every finite structure has a…

Logic in Computer Science · Computer Science 2017-01-11 Manuel Bodirsky

We study the sets of the infinite sentences constructible with a dictionary over a finite alphabet, from the viewpoint of descriptive set theory. Among other things, this gives some true co-analytic sets. The case where the dictionary is…

Logic · Mathematics 2007-10-02 Dominique Lecomte

A standard tool for classifying the complexity of equivalence relations on $\omega$ is provided by computable reducibility. This reducibility gives rise to a rich degree structure. The paper studies equivalence relations, which induce…

Logic · Mathematics 2019-09-27 Nikolay Bazhenov , Manat Mustafa , Luca San Mauro , Mars Yamaleev

We show that the category of N-complexes has a Str\om model structure, meaning the weak equivalences are the chain homotopy equivalences. This generalizes the analogous result for the category of chain complexes (N = 2). The trivial objects…

K-Theory and Homology · Mathematics 2012-07-31 James Gillespie

We exhibit a monoidal structure on the category of finite sets indexed by P-trees for a finitary polynomial endofunctor P. This structure categorifies the monoid scheme (over Spec N) whose semiring of functions is (a P-version of) the…

Category Theory · Mathematics 2014-07-15 Joachim Kock

We prove that every many-sorted $\omega$-categorical theory is completely interpretable in a one-sorted $\omega$-categorical theory. As an application, we give a short proof of the existence of non $G$--compact $\omega$-categorical…

Logic · Mathematics 2011-03-21 Enrique Casanovas , Rodrigo Peláez , Martin Ziegler

There are familiar examples of computable structures having various computable Scott ranks. There are also familiar structures, such as the Harrison ordering, which have Scott rank $\omega_1^{CK}+1$. Makkai produced a structure of Scott…

Logic · Mathematics 2008-03-25 Wesley Calvert , Sergey S. Goncharov , Julia F. Knight