Skip to main content

All Questions

Filter by
Sorted by
Tagged with
5 votes
0 answers
213 views

Friedman's proof of covering lemma for $L$

There is a two-page proof of the covering lemma for $L$ using $\Sigma_n$ substructures (Theorem 3.10) in Sy Friedman's Fine Structure and Class Forcing, compared to the proof that spans about twenty ...
Lxm's user avatar
  • 333
5 votes
1 answer
243 views

Inner model with a $\mathit{\Delta}^1_3$-good well-ordering of the reals

The constructible universe $L$ has some nice properties: $L$ has a $\mathit{\Delta}^1_2$-good well-ordering of $\mathbb{R}$. (Gödel, Addison) For any $\mathit{\Sigma}^1_2$ formula $\varphi(x)$ and a ...
Lorenzo's user avatar
  • 2,286
7 votes
0 answers
207 views

Literature on the reals or their gaps in $L[0^\sharp]$?

I'm doing my Bachelor's Thesis on the continuum in $L$ and $L[0^\sharp]$. In $L$ I study the gaps without new reals (sets of natural numbers) in the hierarchy, as presented in Gaps in the ...
Martín S's user avatar
  • 421
6 votes
0 answers
214 views

Recent literature on the gaps of reals on $L$ or other inner models?

I'm doing my Bachelor's Thesis on Gödel's constructible universe $L$. I'm interested in the gaps without new reals (sets of natural numbers) in the hierarchy, as presented in Gaps in the constructible ...
Martín S's user avatar
  • 421
7 votes
1 answer
335 views

The core model and elementary embeddings

Let $K$ be the core model (below a Woodin cardinal). Let $j \colon K \to M$ be an elementary embedding, where $M$ is well founded. Under which conditions can we conclude that $j$ is an iterated ...
Yair Hayut's user avatar
  • 5,112
5 votes
1 answer
396 views

GCH implies acceptability

I have been studying the concept of acceptability, particularly in its relation to GCH. There are many versions of it in the sources I have found, with some slight variations, and some of them are ...
Rodrigo Freire's user avatar
14 votes
3 answers
934 views

Forcings predicted by core model theory $+$$ZFC$ results proved by the method of core model theory

I have two unrelated question. First question. To motivate the question, let me explain an example. The natural way to force the failure of singular cardinals hypothesis ($SCH$), is to start with a ...
Mohammad Golshani's user avatar
19 votes
2 answers
9k views

The Ultimate L in a Nutshell: On Descriptive Articles

Everybody who catches a fleeting glimpse of Woodin's central papers on Ultimate $L$ (i.e. Suitable Extender Models I & II), admits that they aren't so tempting for lazy readers who don't like to ...
Morteza Azad's user avatar
3 votes
1 answer
253 views

Definition of $M_n^\sharp(X)$ for arbitrary set $X$

The definition of $M_n^\sharp$ in [OIMT10] is the unique sound, $(\omega,\omega_1,\omega_1+1)$-iterable mouse which is not $n$-small, but all of whose proper initial segments are $n$-small. What is ...
Dan Saattrup Nielsen's user avatar
2 votes
0 answers
149 views

Strong determinacy principles for "small" sets

In the course of a (fun but silly) project I'm working on, I've run into the following class of determinacy notions: Suppose I have a "reasonably definable" class $\mathcal{C}$ of games (in the usual ...
Noah Schweber's user avatar
7 votes
1 answer
497 views

Core model with $\omega$ Woodin cardinals

In [KwoM] it is proved that the the core model K exists under the assumption that there is no inner model having a Woodin cardinal and satisfying ZFC. Furthermore, they also mention that the result is ...
Dan Saattrup Nielsen's user avatar
4 votes
0 answers
142 views

Characterization of $L[T_{2n+1}]$ as a direct limit of mice

I am asking for a reference request/proof sketch for the result of Steel that characterizes $L[T_{2n+1}]$ as a direct limit of mice. Given that both $L[T_{2n+1}]$ and $M_{2n}$ have a $\Sigma_{2n+2}$ ...
Cody Dance's user avatar
15 votes
1 answer
408 views

Consistency strength of $\aleph_2$-Souslin hypothesis

Question 1. What is known about the consistency strength of $\aleph_2$-Souslin hypothesis? Question 2. What is known about the consistency strength of having both $\aleph_2$-Souslin hypotheis and $\...
Mohammad Golshani's user avatar
7 votes
0 answers
294 views

Core model for supercompact cardinals and iteration trees

I have a few somehow related questions: Question 1. What do we expect for an inner model $\mathcal{K}$ to be a core model for a supercompact cardinal? What properties should it have, and what ...
Mohammad Golshani's user avatar
5 votes
1 answer
921 views

A Hot Betting On HOD

Remark: This question is based on an open question at the end of a paper by Hamkins, Kirmayer, and Perlmutter: "Generalizations of the Kunen Inconistency". $HOD$ as an inner model of $ZFC$ lies ...
user avatar