Bjorn Poonen's user avatar
Bjorn Poonen's user avatar
Bjorn Poonen's user avatar
Bjorn Poonen
  • Member for 14 years, 3 months
  • Last seen more than a month ago
15 votes
Accepted

Factorization of an irreducible polynomial in the field extension it defines

2 votes

One-step problems in geometry

105 votes
Accepted

Conceptual reason why the sign of a permutation is well-defined?

5 votes
Accepted

Supersingular curves over $\mathbb{F}_q$ and the splitting of $p$

4 votes
Accepted

Cotangent spaces of finite flat group schemes in short exact sequences

3 votes

Do compact complex manifolds fall into countably many families?

10 votes

polynomials in many variables and Hasse principle

18 votes
Accepted

Disjoint images of polynomials

18 votes
Accepted

Two rings...are they isomorphic?

7 votes

Lagrange four-squares theorem: efficient algorithm with units modulo a prime?

8 votes
Accepted

Reverse plane geometry, anyone?

13 votes
Accepted

Proving that any two points on a variety can be joined by a curve; why does Bertini apply?

11 votes
Accepted

Surjectivity of bilinear forms.

30 votes

Integer matrices with no integer eigenvalues

22 votes
Accepted

Images of action of Galois on the Tate module of Elliptic Curve,

3 votes
Accepted

Fundamental domain for symmetric group $S_n$ acting on $\mathop{Gr}(k,n)$?

14 votes
Accepted

What are the normal subgroups of a direct product?

12 votes
Accepted

longest consecutive subsequence of a random permutation

28 votes
Accepted

Is a universally closed morphism of schemes quasi-compact ?

24 votes
Accepted

Example of a smooth morphism where you can't lift a map from a nilpotent thickening?

10 votes

Example of a smooth morphism where you can't lift a map from a nilpotent thickening?

18 votes

Isomorphism problem for commutative algebras and schemes.

6 votes

Homomorphism of Legendre curve

14 votes
Accepted

Waring's problem for matrices

14 votes
Accepted

How to solve Diophantine equations in $F_{p}$?

14 votes

A graph on irrationals where p is adjacent to q if p^q or q^p is rational.

12 votes
Accepted

distribution of degree of minimum polynomial for eigenvalues of random matrix with elements in finite field

5 votes
Accepted

Maximally symmetric smooth projective varieties in CP^2

8 votes

Showing a matrix is negative definite [formerly Showing a sum is always positive]

11 votes
Accepted

An S-unit equation, with S an infinite and sparse set of primes.