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Related papers: Some new computable structures of high rank

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In computability theory and computable analysis, finite programs can compute infinite objects. Presenting a computable object via any program for it, provides at least as much information as presenting the object itself, written on an…

Logic in Computer Science · Computer Science 2014-09-25 Mathieu Hoyrup , Cristobal Rojas

Assuming the obvious definitions (see paper) we show the a decidable model that is effectively prime is also effectively atomic. This implies that two effectively prime (decidable) models are computably isomorphic. This is in contrast to…

Logic · Mathematics 2017-01-31 Peter Cholak , Charlie McCoy

The intended model of the homotopy type theories used in Univalent Foundations is the infinity-category of homotopy types, also known as infinity-groupoids. The problem of higher structures is that of constructing the homotopy types needed…

Logic · Mathematics 2018-07-09 Ulrik Buchholtz

We describe the structure of 0-simple countably compact topological inverse semigroups and the structure of congruence-free countably compact topological inverse semigroups.

Group Theory · Mathematics 2008-04-10 Oleg Gutik , Dušan Repovš

This paper concerns a study of three families of non-compact type symmetric spaces of infinite dimension. Although they have infinite dimension they have finite rank. More precisely, we show they have finite telescopic dimension. We also…

Differential Geometry · Mathematics 2021-04-21 Bruno Duchesne

We classify the 5-dimensional homogeneous geometries in the sense of Thurston. The present paper (part 3 of 3) classifies those in which the linear isotropy representation is nontrivial but reducible. Most of the resulting geometries are…

Geometric Topology · Mathematics 2016-05-25 Andrew Geng

In this paper we extend the approach of M. Cavaleri to effective amenability to the class of computably enumerable groups, i.e. in particular we do not assume that groups are finitely generated. In the case of computable groups we also…

Group Theory · Mathematics 2022-05-16 Karol Duda

Let $M$ be a compact hyperkaehler manifold. The hyperkaehler structure equips $M$ with a set $R$ of complex structures parametrized by $CP^1$, called "the set of induced complex structures". It was known previously that induced complex…

alg-geom · Mathematics 2008-02-03 Misha Verbitsky

Building on work of J. Robinson and A. Shlapentokh, we develop a general framework to obtain definability and decidability results of large classes of infinite algebraic extensions of $\mathbb{F}_p(t)$. As an application, we show that for…

Logic · Mathematics 2024-09-04 Carlos Martinez-Ranero , Dubraska Salcedo , Javier Utreras

A classification theorem is obtained for a class of unital simple separable amenable Z-stable C*-algebras which exhausts all possible values of the Elliott invariant for unital stably finite simple separable amenable Z-stable C*-algebras.…

Operator Algebras · Mathematics 2021-05-05 Guihua Gong , Huaxin Lin , Z. Niu

We classify essential algebras whose irredundant non-refinable covers consist of primal algebras. The proof is obtained by constructing one to one correspondence between such algebras and partial orders on finite sets. Further, we prove…

Logic · Mathematics 2014-06-26 Shohei Izawa

A computably presented algebraic field $F$ has a \emph{splitting algorithm} if it is decidable which polynomials in $F[X]$ are irreducible there. We prove that such a field is computably categorical iff it is decidable which pairs of…

Logic · Mathematics 2018-02-12 Russell Miller , Alexandra Shlapentokh

Scott's information systems provide a categorically equivalent, intensional description of Scott domains and continuous functions. Following a well established pattern in denotational semantics, we define a linear version of information…

Logic in Computer Science · Computer Science 2010-04-08 A. Bucciarelli , A. Carraro , T. Ehrhard , A. Salibra

The article focuses on a class of second countable groups assembled from profinite and discrete by elementary operations. We focus on a rank associated with these groups that measure their complexity, the decomposition rank. A collection of…

Group Theory · Mathematics 2023-10-23 João V. P. e Silva

We compare three notions of effectiveness on uncountable structures. The first notion is that of a $\real$-computable structure, based on a model of computation proposed by Blum, Shub, and Smale, which uses full-precision real arithmetic.…

Logic · Mathematics 2008-09-01 Wesley Calvert

We study the structure and compute the stable rank of C*-algebras of finite higher-rank graphs. We completely determine the stable rank of the C*-algebra when the k-graph either contains no cycle with an entrance, or is cofinal. We also…

Operator Algebras · Mathematics 2021-09-08 David Pask , Adam Sierakowski , Aidan Sims

We study definable ranks of ordered fields, ordered abelian groups, and linear orders. For an arbitrary linear order $\Gamma$, we construct an ordered abelian group $G$ with archimedian spine $\Gamma$ and an ordered field $K$ with natural…

Logic · Mathematics 2025-12-23 Blaise Boissonneau , Lasse Vogel

The theme of the first two sections, is to prepare the framework of how from a ``complicated'' family of so called index models $I \in K_1$ we build many and/or complicated structures in a class $K_2$. The index models are…

Logic · Mathematics 2023-05-19 Saharon Shelah

We formalize the way in which one can think about cluster algebras of infinite rank by showing that every rooted cluster algebra of infinite rank can be written as a colimit of rooted cluster algebras of finite rank. Relying on the proof of…

Representation Theory · Mathematics 2017-07-20 Sira Gratz

We introduce infinite time computable model theory, the computable model theory arising with infinite time Turing machines, which provide infinitary notions of computability for structures built on the reals R. Much of the finite time…

Logic · Mathematics 2007-05-23 Joel David Hamkins , Russell Miller , Daniel Seabold , Steve Warner