Bruno Stonek's user avatar
Bruno Stonek's user avatar
Bruno Stonek's user avatar
Bruno Stonek
  • Member for 13 years, 6 months
  • Last seen this week
  • Paris
102 votes
4 answers
8k views

How is a group made up of simple groups?

68 votes
4 answers
13k views

Center-commutator duality

47 votes
1 answer
6k views

Quotient objects, their universal property and the isomorphism theorems

45 votes
1 answer
4k views

Equivalent conditions for a preabelian category to be abelian

35 votes
3 answers
4k views

If $\sum a_n b_n <\infty$ for all $(b_n)\in \ell^2$ then $(a_n) \in \ell^2$

34 votes
3 answers
2k views

Are the axioms for abelian group theory independent?

30 votes
6 answers
8k views

Right adjoints preserve limits

23 votes
2 answers
1k views

Hopkins-Levitzki: an uncanny asymmetry?

23 votes
3 answers
109k views

What is the probability that a solitaire game be winnable?

21 votes
4 answers
1k views

Why isn't the perfect closure separable?

19 votes
3 answers
2k views

Does Proj induce some equivalence of categories involving graded rings?

18 votes
2 answers
2k views

Is the axiom of universes 'harmless'?

17 votes
1 answer
2k views

Perfect closure is perfect

17 votes
8 answers
3k views

Reference request: is mathematics discovered or created?

17 votes
5 answers
3k views

"The Yoneda embedding reflects exactness" is a direct consequence of Yoneda?

16 votes
2 answers
4k views

Explicit isomorphism $\tilde{H_n}(X)\simeq \tilde{H}_{n+1}(SX)$.

16 votes
3 answers
2k views

What does $ds^2$ mean and how does it specify a metric?

15 votes
2 answers
5k views

Characterizations of the $p$-Prüfer group

14 votes
1 answer
3k views

Hom of finitely generated modules over a noetherian ring

13 votes
6 answers
3k views

For an integrable function $f$, do continuity conditions on its integral affect continuity of $f$?

13 votes
3 answers
2k views

When do regular values form an open set?

12 votes
5 answers
3k views

Examples of comma categories

12 votes
1 answer
239 views

Is every compact hypersurface contained in a sphere which it touches twice?

12 votes
2 answers
5k views

Is an integer a sum of two rational squares iff it is a sum of two integer squares?

11 votes
3 answers
2k views

The torsion submodule of $\prod \mathbb{Z}_p$ is not a direct summand of $\prod \mathbb{Z}_p$

10 votes
2 answers
7k views

Degree of $\sqrt{2}+\sqrt[3]{5}$ over $\mathbb{Q}(\sqrt{2})$ and $\mathbb{Q}(\sqrt[3]{5})$

10 votes
1 answer
2k views

Normal closure of a radical extension is radical

10 votes
2 answers
2k views

Proving the class number of $\mathbb{Q}(\sqrt{-5})$ is 2 using Ireland-Rosen's bound

10 votes
2 answers
5k views

Homology with local coefficients in a $\mathbb{Z}[\pi_1(X)]$-module

9 votes
1 answer
328 views

The groups $[\Sigma^nX,Y]$ versus the homotopy groups