User Zach Teitler

65 votes

Why is the Vandermonde determinant harmonic?

answered Jun 12, 2020 at 14:03

51 votes

Nonequivalent definitions in Mathematics

answered Nov 23, 2017 at 0:10

43 votes

Is pure mathematics useful outside of mathematics itself?

answered May 11, 2021 at 4:02

32 votes

Accepted

Is every real number in [0,1] a product of three (or more) Cantor set's numbers?

answered Dec 22, 2023 at 15:47

31 votes

Accepted

Conjecture: If circular coins of any sizes are in a convex polygonal frame, with each coin touching exactly one edge, then all the coins can move

answered Jan 11, 2023 at 14:15

20 votes

Counterexamples against all odds

answered Aug 8, 2020 at 21:42

19 votes

How would you have answered Richard Feynman's challenge?

answered Dec 5, 2021 at 21:46

15 votes

Accepted

Product of conjugate matrices in $\mathrm{SL}(2, \mathbb{Z})$

answered May 8, 2016 at 10:33

14 votes

What are examples of books which teach the practice of mathematics?

answered Sep 2, 2018 at 17:30

13 votes

Accepted

Sum of multinomals = sum of binomials: why?

answered Jun 3, 2017 at 2:26

12 votes

What is the largest tensor rank of $n \times n \times n$ tensor?

answered Oct 27, 2017 at 3:20

10 votes

Accepted

2x2-determinantal representations of cubic curves

answered Jun 21, 2017 at 14:45

10 votes

Accepted

When is an algebra defined by generators and relations finite-dimensional and satisfies Poincaré duality?

answered Dec 3, 2019 at 1:58

10 votes

Tools from other disciplines useful to mathematics research?

answered Sep 21, 2020 at 7:31

9 votes

Accepted

A different notion of a decomposable symmetric tensor (besides Veronese)

answered Sep 29, 2020 at 0:17

9 votes

Examples of interesting false proofs

answered Jan 10, 2019 at 9:10

9 votes

General principles which lead to good questions in many concrete situations

answered Jul 18, 2018 at 15:56

9 votes

Accepted

Is the Grassmannian contained in a Plücker hyperplane?

answered May 30, 2016 at 19:46

9 votes

Accepted

Is a flattening rank a lower bound for the border rank?

answered Sep 7, 2017 at 3:37

8 votes

What is a fat point?

answered Jun 26, 2017 at 13:11

8 votes

Accepted

Linear spaces secant to Veronese varieties

answered Jan 3, 2021 at 5:16

8 votes

No canonical isomorphism

answered Apr 24, 2021 at 0:50

8 votes

When is 4 qualitatively different than $n\leq 3$?

answered Nov 13 at 14:47

7 votes

Accepted

Classification of curves whose tangent spaces are large

answered Sep 9, 2023 at 1:20

7 votes

Accepted

Waring rank of monomials, and how it depends on the ground field

answered Nov 19, 2022 at 17:15

7 votes

Is computer algebra or symbolic computation an active area of research?

answered Aug 28, 2021 at 0:10

7 votes

Sum of a big divisor and a pseudo-effective divisor

answered Jun 27, 2017 at 18:46

7 votes

Tensor rank of anti-symmetric tensor

answered Oct 26, 2017 at 4:27

7 votes

Accepted

Is the Waring rank homogeneous polynomials sub-multiplicative?

answered Jan 19, 2018 at 3:33

7 votes

Accepted

Can a positive polynomial on sphere be represented as the sum of squares of spherical harmonics

answered Aug 14, 2018 at 20:46

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108 Answers

Why is the Vandermonde determinant harmonic?

Nonequivalent definitions in Mathematics

Is pure mathematics useful outside of mathematics itself?

Is every real number in [0,1] a product of three (or more) Cantor set's numbers?

Conjecture: If circular coins of any sizes are in a convex polygonal frame, with each coin touching exactly one edge, then all the coins can move

Counterexamples against all odds

How would you have answered Richard Feynman's challenge?

Product of conjugate matrices in $\mathrm{SL}(2, \mathbb{Z})$

What are examples of books which teach the practice of mathematics?

Sum of multinomals = sum of binomials: why?

What is the largest tensor rank of $n \times n \times n$ tensor?

2x2-determinantal representations of cubic curves

When is an algebra defined by generators and relations finite-dimensional and satisfies Poincaré duality?

Tools from other disciplines useful to mathematics research?

A different notion of a decomposable symmetric tensor (besides Veronese)

Examples of interesting false proofs

General principles which lead to good questions in many concrete situations

Is the Grassmannian contained in a Plücker hyperplane?

Is a flattening rank a lower bound for the border rank?

What is a fat point?

Linear spaces secant to Veronese varieties

No canonical isomorphism

When is 4 qualitatively different than $n\leq 3$?

Classification of curves whose tangent spaces are large

Waring rank of monomials, and how it depends on the ground field

Is computer algebra or symbolic computation an active area of research?

Sum of a big divisor and a pseudo-effective divisor

Tensor rank of anti-symmetric tensor

Is the Waring rank homogeneous polynomials sub-multiplicative?

Can a positive polynomial on sphere be represented as the sum of squares of spherical harmonics