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Related papers: O-minimal open core is not an elementary property

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There exist NIP and non-NTP$_2$ theories satisfying all the following conditions: It is not o-minimal; All models are strongly locally o-minimal; It has a model which is an expansion of the linearly ordered abelian group over the reals…

Logic · Mathematics 2022-08-18 Masato Fujita

In this paper we give an explicit characterization of o-minimal structures with definable Skolem functions/definable choice. Such structures are, after naming finitely many elements from the prime model, a union of finitely many trivial…

Logic · Mathematics 2022-07-26 Bruno Dinis , Mário J. Edmundo

We prove that in an arbitrary o-minimal structure, every interpretable group is definably isomorphic to a definable one. We also prove that every definable group lives in a cartesian product of one-dimensional definable group-intervals (or…

Logic · Mathematics 2011-11-01 Janak Ramakrishnan , Ya'acov Peterzil , Pantelis Eleftheriou

This article is an investigation of a method of deriving a topology from a space and an elementary submodel containing it. We first define and give the basic properties of this construction, known as $X/M$. In the next section, we construct…

Logic · Mathematics 2015-04-08 Peter Burton

In [O. Le Gal, J.-P. Rolin. An o-minimal structure which does not admit $C^\infty$ cellular decomposition. In: Ann. Inst. Fourier 59 (2009), pp 543-562], the authors construct an o-minimal structure which does not admit smooth…

Logic · Mathematics 2025-02-28 R. Guénet

We show that separability and second-countability are first-order properties among topological spaces definable in o-minimal expansions of $(\mathbb{R},<)$. We do so by introducing first-order characterizations -- definable separability and…

Logic · Mathematics 2025-06-16 Pablo Andújar Guerrero

We prove several structural results on definably compact groups G in o-minimal expansions of real closed fields, such as (i) G is definably an almost direct product of a semisimple group and a commutative group, and (ii) the group (G, .) is…

Logic · Mathematics 2008-11-04 Ehud Hrushovski , Ya'acov Peterzil , Anand Pillay

We establish the first global results for groups definable in tame expansions of o-minimal structures. Let $\mathcal N$ be an expansion of an o-minimal structure $\mathcal M$ that admits a good dimension theory. The setting includes dense…

Logic · Mathematics 2018-07-20 Pantelis E. Eleftheriou

We study the properties of topological spaces $(X,\tau)$, where $X$ is a definable set in an o-minimal structure and the topology $\tau$ on $X$ has a basis that is (uniformly) definable. Examples of such spaces include the canonical…

Logic · Mathematics 2023-10-11 Pablo Andújar Guerrero , Margaret E. M. Thomas

We investigate when the space $\mathcal O_X$ of open subsets of a topological space $X$ endowed with the Scott topology is core compact. Such conditions turn out to be related to infraconsonance of $X$, which in turn is characterized in…

General Topology · Mathematics 2013-04-26 Francis Jordan , Frederic Mynard

We prove a theorem which provides a method for constructing points on varieties defined by certain smooth functions. We require that the functions are definable in a definably complete expansion of a real closed field and are locally…

Logic · Mathematics 2014-02-26 G. O. Jones , A. J. Wilkie

Let $T$ be a consistent o-minimal theory extending the theory of densely ordered groups and let $T'$ be a consistent theory. Then there is a complete theory $T^*$ extending $T$ such that $T$ is an open core of $T^*$, but every model of…

Logic · Mathematics 2017-10-10 Philipp Hieronymi , Travis Nell , Erik Walsberg

We introduce a model category of spaces based on the definable sets of an o-minimal expansion of a real closed field. As a model category, it resembles the category of topological spaces, but its underlying category is a coherent topos. We…

Algebraic Topology · Mathematics 2021-08-27 Reid Barton , Johan Commelin

Definable continuous injective maps defined on definable open sets into the Euclidean spaces of the same dimension are open maps in definably complete locally o-minimal expansions of ordered groups.

Logic · Mathematics 2026-01-27 Masato Fujita

Given a definably compact group G in a saturated o-minimal structure, there is a canonical homomorphism from G to a compact real Lie group F(G). We establish a similar result for the (o-mininimal) universal cover of a definably compact…

Logic · Mathematics 2009-11-30 A. Berarducci , M. Mamino

The main motivation of this paper is the study of first-order model theoretic properties of structures having their roots in modal logic. We will focus on the connections between ultrafilter extensions and ultrapowers. We show that certain…

Logic · Mathematics 2024-05-28 Zalán Molnár

We classify real families of minimal degree rational curves that cover an embedded rational surface. A corollary is that if the projective closure of a smooth surface is not biregular isomorphic to the projective closure of the unit-sphere,…

Algebraic Geometry · Mathematics 2021-03-09 Niels Lubbes

The structures $\langle M,\subseteq^M\rangle$ arising as the inclusion relation of a countable model of sufficient set theory $\langle M,\in^M\rangle$, whether well-founded or not, are all isomorphic. These structures $\langle…

Logic · Mathematics 2017-04-17 Joel David Hamkins , Makoto Kikuchi

We develop tame topology over dp-minimal structures equipped with definable uniformities satisfying certain assumptions. Our assumptions are enough to ensure that definable sets are tame: there is a good notion of dimension on definable…

Logic · Mathematics 2019-09-18 Pierre Simon , Erik Walsberg

We prove that a function definable with parameters in an o-minimal structure is bounded away from infinity as its argument goes to infinity by a function definable without parameters, and that this new function can be chosen independently…

Logic · Mathematics 2011-04-22 Janak Ramakrishnan