Type: Article

n -Luzin gaps

Hrušák, Michael; Guzmán, Osvaldo;

Abstract:

We introduce and study the notion of an n-Luzin gap, which is a natural generalization of a Luzin gap. We prove that under Martin's Axiom, every AD family A of size less than c contains an n-Luzin gap or the corresponding Mrowka-Isbell space Psi(A) is normal. (C) 2013 Elsevier B.V. All rights reserved.