arXiv subjects

Rodrigo Figueiredo

Publications and source records attributed to Rodrigo Figueiredo.

5 recordsLinked to original sources

arXiv2020

On the order theory for $\mathcal{C}^\infty$-reduced $\mathcal{C}^\infty$-Rings and applications

In the present work we carry on the study of the order theory for ($\mathcal{C}^{\infty}-$-reduced) $\mathcal{C}^{\infty}-$-rings initiated in \cite{rings1} (see also \cite{BM2}). In particular, we apply some results of the order theory of $\mathcal{C}^{\infty}-$-fields (e.g., every such field is real closed) to present another approach to the order theory of general $\mathcal{C}^{\infty}-$-rings: "smooth real spectra" (see \cite{separation}). This suggests that a model-theoretic investigation of the class of $\mathcal{C}^{\infty}-$-fields could be interesting and also useful to provide the first steps towards the development of the "Real Algebraic Geometry" of $\mathcal{C}^{\infty}-$-rings.

math.AC↗

arXiv2019

On categories of o-minimal structures

Our aim in this paper is to look at some transfer results in model theory (mainly in the context of o-minimal structures) from the category theory viewpoint.

math.LO↗

arXiv2019

O-minimal de Rham cohomology

O-minimal geometry generalizes both semialgebraic and subanalytic geometries, and has been very successful in solving special cases of some problems in arithmetic geometry, such as André-Oort conjecture. Among the many tools developed in an o-minimal setting are cohomology theories for abstract-definable continuous manifolds such as singular cohomology, sheaf cohomology and \v Cech cohomology, which have been used for instance to prove Pillay's conjecture concerning definably compact groups. In the present paper we elaborate an o-minimal de Rham cohomology theory for abstract-definable $\mathcal{C}^\infty$ manifolds in an o-minimal expansion of the real field which admits smooth cell decomposition and defines the exponential function. We can specify the o-minimal cohomology groups and attain some properties such as the existence of Mayer-Vietoris sequence and the invariance under abstract-definable $\mathcal{C}^\infty$ diffeomorphisms. However, in order to obtain the invariance of our o-minimal cohomology under abstract-definable homotopy we must, working in a tame context that defines sufficiently many primitives, assume the validity of a statement related to Bröcker's question.

math.LO↗

arXiv2019

On Whitney embedding of o-minimal manifolds

We prove a definable version of the Whitney embedding theorem for abstract-definable $\mathcal{C}^p$ manifolds with $1\leq p<\infty$, namely: every abstract-definable $\mathcal{C}^p$ manifold is abstract-definable $C^p$ embedded into $R^N$, for some positive integer $N$. As a consequence, we show that every abstract-definable $\mathcal{C}^p$ manifold has a compatible $\mathcal{C}^{p+1}$ atlas.

math.LO↗

arXiv2019

Remarks on expansions of the real field: tameness, Hardy fields and smooth rings

In the talk \cite{vandendries-matthias-} presented at Logic and Foundations section of ICM-2018, Rio de Janeiro, the authors analyze, under a model-theoretic perspective, three ways to enrich the real continuum by infinitesimal and infinite quantities. In the present work, we present a first model-theoretic connection of another (but related to the previous one) triple of structures: o-minimal structures, Hardy fields and smooth rings.

math.LO↗