Expansions of o-minimal structures by sparse sets

• Autorzy: Harvey Friedman , Chris Miller
• Języki publikacji: EN

Abstrakty

EN

Given an o-minimal expansion ℜ of the ordered additive group of real numbers and E ⊆ ℝ, we consider the extent to which basic metric and topological properties of subsets of ℝ definable in the expansion (ℜ,E) are inherited by the subsets of ℝ definable in certain expansions of (ℜ,E). In particular, suppose that $f(E^{m})$ has no interior for each m ∈ ℕ and $f: ℝ^{m} → ℝ$ definable in ℜ, and that every subset of ℝ definable in (ℜ,E) has interior or is nowhere dense. Then every subset of ℝ definable in (ℜ,(S)) has interior or is nowhere dense, where S ranges over all nonempty subsets of all cartesian products $E^{k}$ (k ≥ 1). The same holds true with "nowhere dense" replaced by any of "null" (in the sense of Lebesgue), "countable", "a finite union of discrete sets", or "discrete". We use this (together with a result of L. van den Dries) to give an example of an expansion of the real field that defines an isomorphic copy of the ordered ring of integers, yet does not define ℤ.

Kategorie tematyczne

• 03C64: Model theory of ordered structures; o-minimality

• Wydawca: Institute of Mathematics Polish Academy of Sciences
• Czasopismo: Fundamenta Mathematicae
• Rocznik: 2001
• Tom: 167
• Numer: 1
• Strony: 55-64

Daty

wydano

2001

Twórcy

autor

Harvey Friedman

• Department of Mathematics, The Ohio State University, 231 West 18th Avenue, Columbus, OH 43210, U.S.A.

autor

Chris Miller

• Department of Mathematics, The Ohio State University, 231 West 18th Avenue, Columbus, OH 43210, U.S.A.

Identyfikatory

DOI

10.4064/fm167-1-4