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fedja
  • Member for 14 years, 5 months
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186 votes
8 answers
12k views

Two commuting mappings in the disk

163 votes
28 answers
54k views

Cool problems to impress students with group theory [closed]

37 votes
2 answers
2k views

Moving one family of commuting self-adjoint operators to another without losing commutativity on the way

28 votes
2 answers
964 views

Can we always shift two disjoint convex bodies a little bit to decrease the volume of their convex hull?

24 votes
1 answer
521 views

What is the minimal volume of the intersection of a self-dual cone and the unit ball?

21 votes
1 answer
719 views

What is the best probabilistic estimate from below for a random polynomial on an arc?

20 votes
2 answers
1k views

Center of mass from the abstract point of view, or could the ancient Greeks invent modern analysis?

20 votes
2 answers
4k views

Teaching stochastic calculus to students who know no measure theory (or PDE, or...)

20 votes
4 answers
2k views

Minkowski sum of small connected sets

20 votes
1 answer
647 views

Can all partial sums $\sum_{k=1}^n f(ka)$ where $f(x)=\log|2\sin(x/2)|$ be non-negative?

19 votes
0 answers
621 views

Is there a simpler proof of the key lemma in the paper by Hiroshi Iriyeh and Masataka Shibata on the 3D Mahler conjecture?

18 votes
1 answer
902 views

Is the ball reducible in some high dimension?

16 votes
1 answer
550 views

Convex bodies with constant maximal section function in odd dimensions

14 votes
1 answer
826 views

Why is there no formula for partial sums of some simple series?

12 votes
3 answers
1k views

Expectation of the product of almost independent Gaussians

12 votes
6 answers
1k views

Suggestions for reducing the transmission rate?

11 votes
0 answers
520 views

Is every Baire metric space a complete metric space in disguise?

10 votes
1 answer
532 views

Does every geometric progression contain a small remainder modulo a large prime?

10 votes
1 answer
730 views

An exponential polynomial with at least one bounded positivity component

10 votes
0 answers
243 views

A slightly generalized existence and uniqueness theorem for integral equations (reference request)

8 votes
1 answer
247 views

An upper bound for the solution of an integro-differential equation

6 votes
1 answer
424 views

A toy model for the t-section problem

5 votes
0 answers
116 views

Minimal covers instead of tilings in Maxwell Allman's problem