Alex Mennen's user avatar
Alex Mennen's user avatar
Alex Mennen's user avatar
Alex Mennen
  • Member for 8 years, 5 months
  • Last seen more than a month ago
25 votes
1 answer
2k views

Can any group be embedded in a simple group?

16 votes
1 answer
824 views

Are the rationals definable in any number field?

13 votes
1 answer
580 views

reverse mathematics of the Lebesgue measurability of analytic sets

10 votes
1 answer
498 views

Does GAGA hold over other topological fields?

9 votes
1 answer
691 views

Is every field the residue field of a discretely valued field of characteristic 0?

9 votes
2 answers
379 views

Is it possible to continuously select a probability distribution over fixed points in Brouwer's fixed point theorem?

8 votes
1 answer
755 views

Semantics of derivations as derivatives

7 votes
2 answers
588 views

Is there a noncomputable set which can be described by a probabilistic Turing machine with bounded error?

7 votes
0 answers
448 views

What Spec-like functors are there?

7 votes
1 answer
329 views

Axiomatizations of arithmetical parts of theories

5 votes
0 answers
215 views

For which topological spaces X does an exponential object Y^X exist for all "nice" topological spaces Y?

5 votes
1 answer
1k views

Conditions under which a linear functional on a space of measures must be integration of a function

5 votes
0 answers
332 views

Which locally ringed spaces are schemifiable?

5 votes
2 answers
469 views

Consistent sentences with no arithmetically definable models

5 votes
0 answers
81 views

One-sided version of the random oracle hypothesis

5 votes
1 answer
169 views

Is there a field with finitely many abelian extensions, that is neither separably closed nor real closed?

5 votes
0 answers
144 views

Does comprehension for formulas in the analytical hierarchy imply comprehension for all formulas in second-order arithmetic?

5 votes
2 answers
278 views

Are there large integer matrices with entries computable in polynomial time, such that all minors are nonzero?

4 votes
1 answer
425 views

Under what conditions is the compact-open topology compactly generated?

4 votes
1 answer
208 views

Are these two definitions of arithmetical hierarchy of real numbers equivalent?

4 votes
0 answers
105 views

Valued fields with quantifier elimination in the Macintyre language

4 votes
1 answer
211 views

Are two recursive well-orderings with the same order type recursively isomorphic?

3 votes
2 answers
130 views

Are there complexity classes X weaker than the linear time hierarchy such that any r.e. set is a coordinate projection of a set in X?

3 votes
2 answers
297 views

Should we expect there to be a problem that is PH-hard but not PSPACE-hard?

2 votes
1 answer
126 views

Is the dual of the category of unital C*-algebras concretizable?

2 votes
1 answer
184 views

Existentially closed partial orders

2 votes
1 answer
554 views

Fiber Dimension Theorem for infinite-dimensional schemes

2 votes
0 answers
165 views

Which Coxeter groups can be realized as affine reflection groups?