Mikhail Borovoi's user avatar
Mikhail Borovoi's user avatar
Mikhail Borovoi's user avatar
Mikhail Borovoi
  • Member for 14 years, 1 month
  • Last seen this week
27 votes
1 answer
1k views

Nonabelian topological fundamental group of a conjugate variety

24 votes
3 answers
2k views

Spin group as an automorphism group

19 votes
3 answers
2k views

Second nonabelian group cohomology: cocycles vs. gerbes

17 votes
2 answers
1k views

Is the wonderful compactification of a spherical homogeneous variety always projective?

15 votes
2 answers
829 views

Elements of arbitrary large order in the first Galois cohomology of an elliptic curve

15 votes
3 answers
1k views

Diagonalizable subgroups of a connected linear algebraic group

13 votes
1 answer
980 views

Is -1 a sum of 2 squares in a certain field K?

13 votes
3 answers
1k views

Infiniteness of the Galois cohomology over a number field with coefficients in a finite Galois module

12 votes
2 answers
678 views

Defining abstract varieties and their morphisms over a finitely generated subfield of the base field

11 votes
2 answers
587 views

To describe an invariant trivector in dimension 8 geometrically

11 votes
1 answer
301 views

Galois cohomology class of a reductive group not coming from a torus

11 votes
2 answers
629 views

Abelian variety with prescribed endomorphism ring

10 votes
1 answer
557 views

Does every Shimura variety contain a generic point defined over a number field?

10 votes
1 answer
521 views

A Galois extension over $\mathbb{Q}$ with Galois group $A_4$ and with cyclic decomposition groups

10 votes
4 answers
2k views

Connected components of the orthogonal group O(2n) in characteristic 2.

9 votes
4 answers
631 views

Algebraic cycles of dimension 2 on the square of a generic abelian surface

9 votes
2 answers
2k views

Mostow's theorem on algebraic groups

9 votes
2 answers
461 views

Automorphisms of $SL_n$ as a variety

9 votes
1 answer
1k views

Nonabelian $H^2$ and Galois descent

9 votes
0 answers
243 views

Rationality of a certain real algebraic variety

9 votes
1 answer
629 views

Group schemes, adeles, double cosets, and étale cohomology

9 votes
1 answer
699 views

Forms of ${\rm SL}(2)$

9 votes
1 answer
362 views

For which subgroups the transfer map kills a given element of a group?

8 votes
2 answers
417 views

Parabolics and simple roots for a special unitary group: reference request

8 votes
1 answer
302 views

Algebraic points of uniformly bounded degree on an algebraic variety

7 votes
1 answer
226 views

Hasse principle for $H^2$ of a maximal torus of a split simply connected group?

7 votes
0 answers
313 views

A basic question on a base change of a homogeneous space of a linear algebraic group

7 votes
2 answers
225 views

Non-semisimple symmetric subgroups of simply connected simple algebraic groups

7 votes
2 answers
1k views

Reductive subgroup corresponding to a subdiagram of the Dynkin diagram of a simple group

7 votes
2 answers
682 views

What does a homogeneous space of a linear algebraic group know about the group?

1
2 3 4 5