User Alex Gavrilov

30 votes

"Long-standing conjectures in analysis ... often turn out to be false"

answered Jul 26, 2018 at 10:03

17 votes

Accepted

For which Millennium Problems does undecidable -> true?

answered Apr 11, 2014 at 17:35

17 votes

Accepted

Does the Gauss-Bonnet theorem apply to non-orientable surfaces?

answered Apr 16, 2019 at 17:29

13 votes

Is $\pi_2$ algebraic?

answered Jun 2, 2014 at 12:23

13 votes

Accepted

History of publication of von Neumann's characterization of orthogonally invariant matrix norms

answered Jan 9, 2018 at 13:33

8 votes

Irrationality measure of arctan(1/3)

answered Apr 8, 2020 at 15:56

8 votes

If $A,B$ are upper triangular matrices such that $AX=XA\implies BX=XB$ for upper triangular $X$, is $B$ a polynomial in $A$?

answered Jul 9, 2018 at 17:42

7 votes

Accepted

Is complex analytic extension of real-analytic diffeomorphism a diffeomorphism ?

answered Jul 5, 2011 at 4:52

6 votes

Gödel's speed-up from constructive to classical logic?

answered Mar 1, 2018 at 11:40

6 votes

Inverse of matrix $D + ADA^T$

answered Aug 6, 2018 at 12:53

6 votes

Lindelöf hypothesis claim

answered Jun 30, 2018 at 13:38

6 votes

Are there examples of conjectures supported by heuristic arguments that have been finally disproved?

answered Aug 18, 2018 at 10:23

5 votes

Accepted

Is this lower bound for a norm of some complex matrices true?

answered Jun 11, 2018 at 16:32

5 votes

The geometry of the solution set of a symmetric equation in four symmetric matrices

answered Aug 23, 2017 at 11:22

5 votes

Is it possible to sum the divergent series with prime coefficients?

answered Aug 27, 2014 at 14:16

4 votes

Accepted

A Hadamard product of the zeros of the Riemann integral. Does it put any constraints on where the $\rho$'s can reside in the critical strip?

answered May 11, 2014 at 14:46

4 votes

Accepted

Stability of Dirichlet data for Helmholtz equation

answered Jun 5, 2012 at 16:28

4 votes

Does $2^n-n$ have infinitely often a prime divisor greater than $n$?

answered Nov 19, 2016 at 15:22

4 votes

What advantage humans have over computers in mathematics?

answered Aug 3, 2017 at 14:27

4 votes

Accepted

Square root of a large sparse symmetric positive definite matrix

answered May 28, 2018 at 13:42

4 votes

Analytic approximations of smooth vector fields

answered Aug 12, 2020 at 11:20

4 votes

Comparing two power-series

answered Jul 27, 2021 at 12:08

3 votes

Partial product of Euler factors

answered Aug 15, 2018 at 15:14

3 votes

If a group $G$ has decidable word problem, must it have a decidable square problem?

answered Aug 13, 2018 at 8:10

3 votes

Accepted

Boundary behavior of power series vs. boundedness of partial sums

answered Feb 4, 2018 at 9:22

3 votes

Accepted

Abhyankar-Moh embedding theorem without algebraic closedness

answered Apr 11, 2018 at 16:27

3 votes

Are there any techniques for solving a differential equation of the form $f ' (x) = f( f( x ) )$?

answered Oct 30, 2012 at 12:37

3 votes

Accepted

Maximising a Rayleigh quotient over a subspace

answered May 17, 2014 at 13:04

3 votes

Accepted

Extension field $\mathbb{C}(t,u)$ over $\mathbb{C}(t^n,u^n)$

answered Sep 10, 2016 at 13:00

2 votes

Formal power series is Taylor expansion of rational function iff Hankel determinants vanish?

answered Sep 11, 2016 at 7:50

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51 Answers

"Long-standing conjectures in analysis ... often turn out to be false"

For which Millennium Problems does undecidable -> true?

Does the Gauss-Bonnet theorem apply to non-orientable surfaces?

Is $\pi_2$ algebraic?

History of publication of von Neumann's characterization of orthogonally invariant matrix norms

Irrationality measure of arctan(1/3)

If $A,B$ are upper triangular matrices such that $AX=XA\implies BX=XB$ for upper triangular $X$, is $B$ a polynomial in $A$?

Is complex analytic extension of real-analytic diffeomorphism a diffeomorphism ?

Gödel's speed-up from constructive to classical logic?

Inverse of matrix $D + ADA^T$

Lindelöf hypothesis claim

Are there examples of conjectures supported by heuristic arguments that have been finally disproved?

Is this lower bound for a norm of some complex matrices true?

The geometry of the solution set of a symmetric equation in four symmetric matrices

Is it possible to sum the divergent series with prime coefficients?

A Hadamard product of the zeros of the Riemann integral. Does it put any constraints on where the $\rho$'s can reside in the critical strip?

Stability of Dirichlet data for Helmholtz equation

Does $2^n-n$ have infinitely often a prime divisor greater than $n$?

What advantage humans have over computers in mathematics?

Square root of a large sparse symmetric positive definite matrix

Analytic approximations of smooth vector fields

Comparing two power-series

Partial product of Euler factors

If a group $G$ has decidable word problem, must it have a decidable square problem?

Boundary behavior of power series vs. boundedness of partial sums

Abhyankar-Moh embedding theorem without algebraic closedness

Are there any techniques for solving a differential equation of the form $f ' (x) = f( f( x ) )$?

Maximising a Rayleigh quotient over a subspace

Extension field $\mathbb{C}(t,u)$ over $\mathbb{C}(t^n,u^n)$

Formal power series is Taylor expansion of rational function iff Hankel determinants vanish?