MathOverflow is a question and answer site for professional mathematicians. It only takes a minute to sign up.

Sign up to join this community
Anybody can ask a question
Anybody can answer
The best answers are voted up and rise to the top

Top Questions

20 votes
8 answers
4k views

Why is integer factoring hard while determining whether an integer is prime easy?

40 votes
2 answers
7k views

Consequences of Kirti Joshi's new preprint about p-adic Teichmüller theory on the validity of IUT and on the ABC conjecture

33 votes
1 answer
2k views

Ruling out the existence of a strange polynomial

6 votes
9 answers
2k views

Papers of the masters translated to English in one location

5 votes
4 answers
2k views

Most important results in 2022

18 votes
2 answers
2k views

Is there an analytic non-linear function that maps rational numbers to rational numbers and it maps irrational numbers to irrational numbers?

23 votes
2 answers
2k views

What is the origin/history of the following very short definition of the Lebesgue integral?

19 votes
5 answers
816 views

What is the relationship between $\sum_{n=0}^\infty f(n) x^n$ and $-\sum_{n=1}^\infty f(-n) x^{-n}$?

16 votes
3 answers
2k views

Why do Grothendieck topologies used in algebraic geometry typically involve finiteness conditions?

11 votes
2 answers
2k views

Can linear logic be used to resolve unexpected hanging/surprise examination paradox?

15 votes
5 answers
853 views

Strategic vs. tactical closure

23 votes
3 answers
1k views

Does there exist a continuous function $f(x)$ such that $f(0)=0$ and $0<\lim_{n\to\infty}\prod_{k=1}^n f(k/n)<\infty$?

9 votes
4 answers
595 views

Compilation of strategies to show that some constant is irrational

15 votes
2 answers
1k views

Why are operads sometimes better than algebraic theories?

8 votes
2 answers
2k views

Why do almost all points in the unit interval have Kolmogorov complexity 1?

27 votes
2 answers
565 views

Is there a flat manifold with trivial first homology?

8 votes
1 answer
1k views

For a non-square, is there a prime number for which it is a primitive root?

22 votes
1 answer
1k views

A property of even continuous functions on the sphere

9 votes
1 answer
4k views

Did Zhang weaken the constant in his Landau-Siegel zero paper to get the current year?

6 votes
2 answers
597 views

Projective objects in the derived category of chain complexes

3 votes
4 answers
871 views

Representation of the Dirac delta function

11 votes
2 answers
858 views

Not very transitive actions

11 votes
2 answers
1k views

Is there a contractible hyperbolic 3-orbifold of finite volume?

8 votes
1 answer
852 views

Definable set in ZF that cannot be proved to be Borel

10 votes
3 answers
447 views

Centre of orbifold fundamental group of torus (Klein bottle) with one cone point

9 votes
1 answer
862 views

Ruling out the existence of a strange polynomial II

3 votes
3 answers
369 views

Quantitative analytic continuation estimate for a function small on a set of positive measure

9 votes
1 answer
588 views

The $9$th tetration of $-\sqrt2$

5 votes
2 answers
602 views

Checking that the image of a curve is not contained in a hyperplane

4 votes
1 answer
470 views

Why is $\mathrm{SO}(4)$ not a simple Lie group?

6 votes
2 answers
422 views

Normalizer of maximal torus is maximal in compact simple group

9 votes
1 answer
298 views

First prime of the form $x_i$ for $x_0=658$ and $x_i=1+2x_{i-1}$

17 votes
1 answer
375 views

Topology of the space of embedded genus $g$ surfaces in $S^3$

13 votes
1 answer
578 views

Is an inextensible manifold necessarily compact?

23 votes
2 answers
567 views

"All retracts are closed" and "all compacts are closed"

2 votes
1 answer
914 views

Reference on the Collatz conjecture [closed]

13 votes
1 answer
703 views

Can you build the surreal numbers as a simple direct limit of ordered fields?

8 votes
2 answers
171 views

Commutation classes of reduced decompositions of the longest element of the Weyl group with one element

7 votes
1 answer
604 views

Converse of closed graph theorem

8 votes
2 answers
559 views

How was Claim 5 in "A non-linear generalisation of the Loomis–Whitney inequality and applications" thought up?

1 vote
2 answers
351 views

How to prove that $1/ ((y+z) x^4) + 1/ ((z+x) y^4) + 1/ ((x+y) z^4) \geq 3/2$ for $x, y, z>0$ such that $xyz=1$? [closed]

9 votes
1 answer
547 views

Elementary theory of the category of relations

21 votes
0 answers
6k views

Philosophy behind Zhang's 2022 preprint on the Landau–Siegel zero

9 votes
1 answer
838 views

True origin of the term "Spline"

5 votes
3 answers
453 views

The relative error of approximating a binomial

13 votes
1 answer
389 views

Applications of equivariant homotopy theory to representation theory

14 votes
1 answer
635 views

Is there a good theory of solid vector spaces?

8 votes
1 answer
692 views

What's the intuition for weighted limits?


Looking for more? Browse the complete list of questions, or popular tags. Help us answer unanswered questions.