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Alex Mennen
  • Member for 6 years, 9 months
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25 votes
1 answer
2k views

Can any group be embedded in a simple group?

16 votes
1 answer
752 views

Are the rationals definable in any number field?

13 votes
1 answer
470 views

reverse mathematics of the Lebesgue measurability of analytic sets

10 votes
1 answer
430 views

Does GAGA hold over other topological fields?

9 votes
1 answer
427 views

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

8 votes
2 answers
288 views

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

7 votes
1 answer
683 views

Semantics of derivations as derivatives

7 votes
2 answers
571 views

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

7 votes
0 answers
395 views

What Spec-like functors are there?

7 votes
1 answer
298 views

Axiomatizations of arithmetical parts of theories

5 votes
0 answers
178 views

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

5 votes
1 answer
840 views

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

5 votes
0 answers
315 views

Which locally ringed spaces are schemifiable?

5 votes
2 answers
457 views

Consistent sentences with no arithmetically definable models

5 votes
0 answers
72 views

One-sided version of the random oracle hypothesis

5 votes
1 answer
167 views

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

5 votes
2 answers
254 views

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

4 votes
0 answers
133 views

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

4 votes
1 answer
188 views

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

4 votes
0 answers
97 views

Valued fields with quantifier elimination in the Macintyre language

4 votes
1 answer
199 views

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

3 votes
2 answers
103 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
244 views

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

2 votes
1 answer
120 views

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

2 votes
1 answer
173 views

Existentially closed partial orders

2 votes
1 answer
510 views

Fiber Dimension Theorem for infinite-dimensional schemes

2 votes
0 answers
162 views

Which Coxeter groups can be realized as affine reflection groups?