mikhail skopenkov's user avatar
mikhail skopenkov's user avatar
mikhail skopenkov's user avatar
mikhail skopenkov
  • Member for 12 years, 11 months
24 votes
6 answers
5k views

Pythagorean 5-tuples

23 votes
4 answers
4k views

Convergence of finite element method: counterexamples

15 votes
1 answer
585 views

Is the ring of quaternionic polynomials factorial?

10 votes
2 answers
1k views

When the determinant of a 2x2 polynomial matrix is a square?

5 votes
2 answers
1k views

Canonical form for a pair of quadratic forms

3 votes
2 answers
1k views

Isolated conics on a del Pezzo surface

1 vote
0 answers
331 views

Singular conics on certain algebraic surfaces

0 votes
3 answers
928 views

Names of certain surfaces

0 votes
0 answers
101 views

Conditions under which the degree of an algebraic surface equals the degree of its planar section