Noah Schweber's user avatar
Noah Schweber's user avatar
Noah Schweber's user avatar
Noah Schweber
  • Member for 13 years, 8 months
  • Last seen this week
11 votes

Special rational numbers that appear as answers to natural questions

11 votes

What notable theorems cannot be automatically proven without choice using Shoenfield absoluteness?

11 votes

Ideals generated by Turing independent sets

11 votes

Computability complexity of the first-order theory of arithmetic?

11 votes
Accepted

What is the Turing degree associated with an ultrafilter $U$?

11 votes
Accepted

Does ZF+AD have any unusual arithmetic consequences?

10 votes
Accepted

Enumeration Hierarchies

10 votes

Can only the constructible sets be proven to exist in $ZF$ without benefit of extra assumptions?

10 votes

Paul Cohen on genesis of method of forcing and mathematical similarities

10 votes
Accepted

Is there a continuous surjection $\omega^\omega\to \mathbb{R}$?

10 votes

Formalizations of The Matchstick Diagram Representation of Ordinals

10 votes
Accepted

Does there exist inconsistent axiom schemata which require arbitrary long proofs of their inconsistency?

10 votes

Can Cantor's theorem be proved in Parameter Free Zermelo?

10 votes

Application of Fraïssé construction in set theory

10 votes

The status of 'the consistency of NF relative to ZF'

10 votes
Accepted

Is there a consistent, unsound, $\omega$-inconsistent, effective theory that doesn't prove its own inconsistency?

10 votes

What are some nice uses of ultraproducts/ultrapowers?

10 votes
Accepted

Good source for admissible set theory?

10 votes
Accepted

Comprehension axiom that helps in the opposite direction

10 votes

Consistency of $c=2^{\aleph_0}=2^{\aleph_1}=\ldots=2^{\aleph_n}\ldots$, for every $n<\omega$

10 votes
Accepted

Gentzen's result on PA

10 votes

Initiation to constructive mathematics

9 votes
Accepted

Arithmetic statement which is independent, and whose independence is independent, and so on?

9 votes

Are there structures in a finite signature that are recursively categorically axiomatizable in SOL but not finitely categorically axiomatizable?

9 votes

Example of a $\Pi^2_2$ sentence?

9 votes

Is Axiom of Choice equivalent to its version for families of sets, indexed by ordinals?

9 votes
Accepted

Is there a proof of independence of AC from Z that is done in Z?

9 votes
Accepted

What is the meaning of $\alpha^{+L}$ for $\alpha$ an infinite countable ordinal?

9 votes
Accepted

What is an axiomatization of the equality-free theory of antisymmetric relations?

9 votes

Operations on the set of large cardinal axioms

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