User Terry Tao

133 votes

5 answers

29k views

Does the inverse function theorem hold for everywhere differentiable maps?

asked Sep 9, 2011 at 23:09

107 votes

6 answers

18k views

How small can a sum of a few roots of unity be?

asked Nov 14, 2010 at 20:54

100 votes

5 answers

11k views

Is there a high level reason why the inverse square law of gravitation yields periodic orbits without precession?

asked Oct 16, 2019 at 15:23

91 votes

8 answers

16k views

Is there a natural random process that is rigorously known to produce Zipf's law?

asked Sep 18, 2010 at 16:24

86 votes

7 answers

20k views

How many orders of infinity are there?

asked Jun 26, 2010 at 17:40

81 votes

4 answers

12k views

Can a group be a universal Turing machine?

asked Feb 13, 2012 at 19:50

73 votes

10 answers

10k views

Riemannian surfaces with an explicit distance function?

asked Sep 3, 2010 at 19:06

67 votes

3 answers

11k views

Is this differential identity known?

asked Jun 3, 2015 at 16:06

63 votes

7 answers

4k views

What well known results with countability assumptions can be naturally extended to uncountable settings?

asked Jan 6, 2022 at 18:41

59 votes

4 answers

4k views

When can one continuously prescribe a unit vector orthogonal to a given orthonormal system?

asked Nov 5, 2018 at 15:40

53 votes

7 answers

6k views

Are there any undecidability results that are not known to have a diagonal argument proof?

asked Sep 6, 2023 at 17:11

50 votes

2 answers

3k views

Small residue classes with small reciprocal

asked Jul 5, 2011 at 1:47

50 votes

1 answer

6k views

Unconditional nonexistence for the heat equation with rapidly growing data?

asked Aug 5, 2011 at 16:59

47 votes

6 answers

5k views

Non-enumerative proof that there are many derangements?

asked Jan 19, 2012 at 17:38

45 votes

1 answer

3k views

Is there a nullstellensatz for trigonometric polynomials?

asked Mar 20, 2021 at 20:57

44 votes

5 answers

6k views

Finding a 1-form adapted to a smooth flow

asked Jul 4, 2017 at 10:16

43 votes

2 answers

4k views

How much of character theory can be done without Schur's lemma or the Artin-Wedderburn theorem?

asked May 21, 2013 at 16:39

43 votes

1 answer

2k views

In the category of sigma algebras, are all epimorphisms surjective?

asked May 16, 2020 at 22:29

42 votes

1 answer

3k views

Is a symplectic camel actually prohibited from passing through the eye of a needle?

asked Mar 26, 2020 at 20:44

39 votes

2 answers

4k views

Can random variables that almost surely solve equations be repaired to surely solve these equations?

asked Nov 25, 2019 at 16:17

39 votes

2 answers

4k views

Why are Schur multipliers of finite simple groups so small?

asked May 17, 2013 at 17:39

37 votes

2 answers

3k views

When can a function be made positive by averaging?

asked Nov 1, 2018 at 23:46

35 votes

3 answers

5k views

What is the standard notation for a multiplicative integral?

asked Jul 20, 2010 at 22:18

35 votes

2 answers

3k views

"Transitivity" of the Stone-Cech compactification

asked Apr 16, 2010 at 18:23

35 votes

2 answers

3k views

What is the most direct proof of the Riemann hypothesis for Dirichlet L-functions over function fields?

asked May 14, 2019 at 23:21

33 votes

3 answers

2k views

Polar body of a convex body that avoids a lattice

asked Aug 5, 2010 at 9:31

33 votes

1 answer

4k views

An etale version of the van Kampen theorem

asked Oct 24, 2012 at 5:26

31 votes

1 answer

3k views

Is there a cheap proof of power savings for exponential sums over finite fields?

asked Jul 30, 2013 at 18:29

31 votes

1 answer

2k views

Is this formal noncommutative power series identity known?

asked Jun 16, 2020 at 19:07

30 votes

1 answer

3k views

Is there an algebraic geometry analogue of the closed graph theorem?

asked Nov 19, 2012 at 19:14

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53 Questions

Does the inverse function theorem hold for everywhere differentiable maps?

How small can a sum of a few roots of unity be?

Is there a high level reason why the inverse square law of gravitation yields periodic orbits without precession?

Is there a natural random process that is rigorously known to produce Zipf's law?

How many orders of infinity are there?

Can a group be a universal Turing machine?

Riemannian surfaces with an explicit distance function?

Is this differential identity known?

What well known results with countability assumptions can be naturally extended to uncountable settings?

When can one continuously prescribe a unit vector orthogonal to a given orthonormal system?

Are there any undecidability results that are not known to have a diagonal argument proof?

Small residue classes with small reciprocal

Unconditional nonexistence for the heat equation with rapidly growing data?

Non-enumerative proof that there are many derangements?

Is there a nullstellensatz for trigonometric polynomials?

Finding a 1-form adapted to a smooth flow

How much of character theory can be done without Schur's lemma or the Artin-Wedderburn theorem?

In the category of sigma algebras, are all epimorphisms surjective?

Is a symplectic camel actually prohibited from passing through the eye of a needle?

Can random variables that almost surely solve equations be repaired to surely solve these equations?

Why are Schur multipliers of finite simple groups so small?

When can a function be made positive by averaging?

What is the standard notation for a multiplicative integral?

"Transitivity" of the Stone-Cech compactification

What is the most direct proof of the Riemann hypothesis for Dirichlet L-functions over function fields?

Polar body of a convex body that avoids a lattice

An etale version of the van Kampen theorem

Is there a cheap proof of power savings for exponential sums over finite fields?

Is this formal noncommutative power series identity known?

Is there an algebraic geometry analogue of the closed graph theorem?