Paul Erdős’s (1913-1996)
András Sárközy (1997)
Acta Arithmetica
Similarity:
András Sárközy (1997)
Acta Arithmetica
Similarity:
Jun Hu, Charles Tresser (1998)
Fundamenta Mathematicae
Similarity:
We show that in any family of stunted sawtooth maps, the set of maps whose set of periods is the set of all powers of 2 has no interior point. Similar techniques then allow us to show that, under mild assumptions, smooth multimodal maps whose set of periods is the set of all powers of 2 are infinitely renormalizable with the diameters of all periodic intervals going to zero as the period goes to infinity.
Robbert Fokkink, Lex Oversteegen (1996)
Fundamenta Mathematicae
Similarity:
A lamination is a continuum which locally is the product of a Cantor set and an arc. We investigate the topological structure and embedding properties of laminations. We prove that a nondegenerate lamination cannot be tree-like and that a planar lamination has at least four complementary domains. Furthermore, a lamination in the plane can be obtained by a lakes of Wada construction.
Chris Miller, Patrick Speissegger (1999)
Fundamenta Mathematicae
Similarity:
The open core of a structure ℜ := (ℝ,<,...) is defined to be the reduct (in the sense of definability) of ℜ generated by all of its definable open sets. If the open core of ℜ is o-minimal, then the topological closure of any definable set has finitely many connected components. We show that if every definable subset of ℝ is finite or uncountable, or if ℜ defines addition and multiplication and every definable open subset of ℝ has finitely many connected components, then the open core...
C. Ash, J. Knight (1994)
Fundamenta Mathematicae
Similarity:
Let A be a recursive structure, and let ψ be a recursive infinitary sentence involving a new relation symbol. The main result of the paper gives syntactical conditions which are necessary and sufficient for every recursive copy of A to have a recursive expansion to a model of ψ, provided A satisfies certain decidability conditions. The decidability conditions involve a notion of rank. The main result is applied to prove some earlier results of Metakides-Nerode and Goncharov. In these...
Daniel Coray, Constantin Manoil (1996)
Acta Arithmetica
Similarity:
Carlos González (1995)
Fundamenta Mathematicae
Similarity:
We investigate the relative consistency and independence of statements which imply the existence of various kinds of dense orders, including dense linear orders. We study as well the relationship between these statements and others involving partition properties. Since we work in ZF (i.e. without the Axiom of Choice), we also analyze the role that some weaker forms of AC play in this context