38

Questions
votes newest views recent
5
11
votes
0
answers
402
views

Can there be an almost-special not-fully-special Aronszajn tree?

mar 26 12 at 7:36 Joel David Hamkins 75.4k●8●188●346

 
10
votes
0
answers
262
views

Can a model of set theory be realized as a Cohen-subset forcing extension in two different ways, with different grounds and different cardinals?

feb 1 at 20:57 Joel David Hamkins 75.4k●8●188●346

1
10
votes
2
answers
432
views

What is the computational-complexity-theoretic analogue of computable inseparability? For example, if P is not NP, are there disjoint NP sets with no separation in P?

mar 1 12 at 14:21 Emil Jeřábek 10.7k●1●24●41

2
10
votes
4
answers
598
views

What is the spectrum of possible cofinality types for cuts in an ordered field? Or in a model of the hyperreals? Or in a nonstandard model of arithmetic?

aug 12 11 at 10:36 Emil Jeřábek 10.7k●1●24●41

2
10
votes
2
answers
387
views

Which are the rigid suborders of the real line?

dec 29 09 at 5:23 François G. Dorais♦ 22.7k●2●49●114

6
10
votes
4
answers
663
views

Does every decidable question about finitely presented groups amount to a question about abelian groups?

feb 27 10 at 17:33 HW 10.1k●1●23●66

1
8
votes
4
answers
625
views

If Q is a subset of the plane of size less than continuum, then does every closed F in Q extend to a closed connected G in the plane with the same trace on Q? (Or is this independent of ZFC?)

nov 17 10 at 16:10 vm 1

 
7
votes
1
answer
277
views

Can there be a global linear ordering of the universe without a global well-ordering of the universe?

nov 3 at 18:07 Joel David Hamkins 75.4k●8●188●346

prev 1 2 3 4