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Top Questions

18 votes
2 answers
1k views

What's the probability that two numbers share the same totient function value?

11 votes
3 answers
806 views

Computationally inspired theorems and conjectures in knot theory

11 votes
1 answer
884 views

Primes whose squares add up to another square

11 votes
1 answer
521 views

Can a category without any nontrivial finite products admit group objects?

14 votes
1 answer
501 views

Irreducible representations of $S_n$

7 votes
2 answers
355 views

Accumulation points of $(3^n)$ in ${\bf Z}_2$

12 votes
1 answer
743 views

Is every set of cardinals bounded?

7 votes
3 answers
549 views

When does a smooth $\mathrm{SO}(n)$-action extend to an $\mathrm{O}(n)$-action?

4 votes
3 answers
413 views

Cardinal arithmetic inequalities according to ZF

7 votes
2 answers
864 views

Metamathematical/philosophical understanding of the smallest aleph

16 votes
1 answer
312 views

Can every Sidon set of size 3 be extended to a finite perfect difference set?

12 votes
2 answers
748 views
+50

Can Lebesgue's differentiation theorem fail almost everywhere?

7 votes
2 answers
667 views

Which conjectures have been solved (or partially solved) using entropy methods?

9 votes
2 answers
451 views

Does every reduced ring inject into a von Neumann regular one, constructively?

6 votes
1 answer
534 views

Extension of definition of distance

6 votes
2 answers
499 views

Result seemingly quoted from SGA

15 votes
1 answer
381 views

Chains of nulls sets: on a question of Elkies (sort of)

6 votes
2 answers
201 views

Power set of a (Grothendieck) Galois extension

11 votes
2 answers
140 views

Relation between completions of $U_q(\mathfrak{sl}_2)$

6 votes
1 answer
405 views

Direct sum and tensor product

5 votes
1 answer
377 views

When is the Yoneda extension fully faithful?

7 votes
1 answer
304 views

Are there higher amorphous sets in the determinacy world?

6 votes
1 answer
165 views

Etale cohomological dimension of affinoid perfectoid spaces for $\ell$-torsion sheaves ($\ell \ne p$)

4 votes
1 answer
168 views

Do we have Beilinson type resolution of partial diagonals?

4 votes
1 answer
288 views

A universal ordering on the sets in a (Turing) degree

3 votes
1 answer
360 views

About Cohen forcing

4 votes
1 answer
280 views

Relationship between Shimura varieties and the moduli stack of principal bundles on a curve

4 votes
1 answer
265 views

Cancellation in stable infinity-categories

3 votes
1 answer
182 views

A universal additive complement

7 votes
1 answer
294 views

Partitions of R into meager/measure zero sets

8 votes
1 answer
255 views

Patterns in group cohomology for Abelian groups

4 votes
1 answer
149 views

When is $\Theta$ a (weakly) Lowenheim-Skolem cardinal?

5 votes
1 answer
188 views

Is Street's nerve fully faithful?

4 votes
1 answer
146 views

When is a $< \kappa$-support iteration of $< \kappa$-closed, $\kappa^+$-cc forcings also so?

1 vote
1 answer
297 views

Question on Cohen forcing

5 votes
1 answer
158 views

Is $ H= (-\Delta)^{\alpha/2} + (X^2)^{\beta/2}$, $\frac{1}{\alpha}+\frac{1}{\beta} = 1$ a quantum harmonic oscillator?

4 votes
1 answer
220 views

Gluing topological spaces

5 votes
1 answer
198 views

On the quantum SL(2) group

3 votes
1 answer
246 views

Probability measures on a non-separable space

4 votes
2 answers
186 views

Recurrence for a sequence defined by an algebraic generating function

4 votes
1 answer
234 views

Colimit of parallel morphisms in stable $\infty$-categories

3 votes
1 answer
221 views

Is $\mathbb{Z}_{>0}$ diophantine in $(\mathbb{Q}_{>0},+,\cdot,1)$?

11 votes
0 answers
281 views

How close is the "bioctonionic projective plane" to an actual projective plane?

3 votes
1 answer
218 views

A new generalization of Euler product formula?

12 votes
0 answers
262 views
+100

Combinatorial interpretation of q-Narayana numbers for q=-1

3 votes
1 answer
153 views

Rings for which every module of projective dimension at most 1 is projective

1 vote
1 answer
224 views

On properties of quotients on the form $G \rightarrow G/H$ for $H \subseteq G$ a closed subgroup scheme

5 votes
0 answers
287 views

What is the inertia-Deligne group?


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