User Bjorn Poonen

294 votes

8 answers

22k views

Polynomial representing all nonnegative integers

asked Dec 25, 2009 at 6:40

63 votes

1 answer

7k views

Smooth proper scheme over Z

asked Dec 23, 2009 at 1:21

47 votes

2 answers

4k views

Collapsible group words

asked Feb 15, 2010 at 5:23

46 votes

1 answer

6k views

Determinant of a determinant

asked Oct 31, 2014 at 16:34

46 votes

15 answers

11k views

Strong induction without a base case

asked Jan 16, 2010 at 6:16

39 votes

2 answers

2k views

Do compact complex manifolds fall into countably many families?

asked May 1, 2017 at 22:18

33 votes

1 answer

1k views

Is the group of integer points on a finite-type group scheme over Z finitely presented?

asked Apr 28, 2010 at 2:42

26 votes

1 answer

3k views

Is every curve birational to a smooth affine plane curve?

asked Dec 24, 2009 at 3:40

21 votes

1 answer

1k views

Does every relative curve have a Picard scheme?

asked Nov 10, 2014 at 13:46

Stack Exchange Network

9 Questions

Polynomial representing all nonnegative integers

Smooth proper scheme over Z

Collapsible group words

Determinant of a determinant

Strong induction without a base case

Do compact complex manifolds fall into countably many families?

Is the group of integer points on a finite-type group scheme over Z finitely presented?

Is every curve birational to a smooth affine plane curve?

Does every relative curve have a Picard scheme?