Piotr Hajlasz's user avatar
Piotr Hajlasz's user avatar
Piotr Hajlasz's user avatar
Piotr Hajlasz
  • Member for 6 years
  • Last seen this week
191 votes
12 answers
30k views

Do you know important theorems that remain unknown?

47 votes
2 answers
5k views

Well known theorems that have not been proved

38 votes
4 answers
4k views

Existence of a strange measure

31 votes
3 answers
1k views

Non embedding of $Y\times Y$ into $\mathbb{R}^3$

29 votes
2 answers
1k views

Open problems in Sobolev spaces

27 votes
2 answers
1k views

Rademacher theorem

20 votes
1 answer
1k views

Carnot-Carathéodory metric

20 votes
2 answers
3k views

Non-differentiable Lipschitz functions

20 votes
3 answers
1k views

Convergence of convex functions

19 votes
3 answers
1k views

Rational homotopy groups of $S^2\vee S^2$

19 votes
1 answer
2k views

Sobolev and Poincare inequalities on compact Riemannian manifolds

18 votes
0 answers
685 views

Homotopy groups of spheres and differential forms

18 votes
4 answers
3k views

Problems in advanced calculus

16 votes
0 answers
588 views

Isoperimetric inequality and geometric measure theory

16 votes
2 answers
2k views

The Lefschetz operator

15 votes
1 answer
886 views

Second order differentiability of convex functions

15 votes
2 answers
1k views

Could Kronecker accept a proof of Goodstein's theorem?

15 votes
4 answers
1k views

Steinhaus theorem and Hausdorff dimension

14 votes
1 answer
812 views

Extending diffeomorphisms

14 votes
3 answers
1k views

Linking topological spheres

13 votes
1 answer
2k views

Unique smooth structure on 3-manifolds

13 votes
1 answer
533 views

Regularity of geodesics

13 votes
1 answer
1k views

Aleksandrov's proof of the second order differentiability of convex functions

13 votes
2 answers
653 views

Regularity of convex sets in $\mathbb{R}^n$

12 votes
0 answers
386 views

Is the Lipschitz structure on $\mathbb{S}^4$ unique?

12 votes
1 answer
471 views

$\pi_k(\mathbb{S}^n\vee\mathbb{S}^n)$

12 votes
2 answers
928 views

Set of points with a unique closest point in a compact set

12 votes
1 answer
614 views

Isotopic diffeomorphisms of the sphere

11 votes
1 answer
910 views

Coarea inequality, Eilenberg inequality

11 votes
3 answers
743 views

Non embedding of the Heisenberg group