On Nicely Definable Forcing Notions

On Nicely Definable Forcing Notions

We prove that if Q is a nw-nep forcing then it cannot add a dominating real. We also show that amoeba forcing cannot be P(X)/I if I is an א1-complete ideal. Furthermore, we generalize the results of [12].

On Nicely Definable Forcing Notions Sh711

We prove that if Q is a nw-nep forcing then it cannot add a dominating real. We also show that amoeba forcing cannot be P(X)/I if I is an א1-complete ideal. Furthermore, we generalize the results of [Sh 480]. I would like to thank Alice Leonhardt for the beautiful typing. This research was partially supported by the Israel Science Foundation founded by the Israel Academy of Sciences and Humanit...

Simple Forcing Notions and Forcing Axioms

Some considerations on amoeba forcing notions

In this paper we analyse some notions of amoeba for tree forcings. In particular we introduce an amoeba-Silver and prove that it satisfies quasi pure decision but not pure decision. Further we define an amoeba-Sacks and prove that it satisfies the Laver property. We also show some application to regularity properties. We finally present a generalized version of amoeba and discuss some interesti...

Forcing notions in inner models

There is a partial order P preserving stationary subsets of !1 and forcing that every partial order in the ground model V that collapses a su ciently large ordinal to !1 over V also collapses !1 over V P. The proof of this uses a coding of reals into ordinals by proper forcing discovered by Justin Moore and a symmetric extension of the universe in which the Axiom of Choice fails. Also, using on...