Yuhao Huang's user avatar
Yuhao Huang's user avatar
Yuhao Huang's user avatar
Yuhao Huang
  • Member for 14 years, 5 months
51 votes
7 answers
11k views

Why forgetful functors usually have LEFT adjoint?

14 votes
4 answers
6k views

"Counter"-example for Gauss's Lemma on irreducible polynomials

10 votes
6 answers
6k views

Figure out the roots from the Dynkin diagram

34 votes
8 answers
5k views

Is there a "knot theory" for graphs?

27 votes
5 answers
5k views

Why does the (S2) property of a ring correspond to the Hartogs phenomenon?

26 votes
5 answers
4k views

Which algebraic varieties admit a morphism to a curve?

16 votes
6 answers
4k views

Representation of Groupoids

24 votes
2 answers
4k views

Why is the decomposition theorem awesome?

10 votes
6 answers
3k views

How do you present a non-existence theorem?

14 votes
3 answers
3k views

What functor does Grassmannian represent?

29 votes
6 answers
3k views

Why are finiteness conditions important (and how to recognize them)?

10 votes
2 answers
3k views

What are unramified morphisms like?

15 votes
4 answers
3k views

How does one motivates the method of separation of variables when teaching PDE's?

7 votes
3 answers
3k views

How many commuting nilpotent matrices are there?

14 votes
4 answers
2k views

Is there any generalization of the Dold-Kan correspondence?

1 vote
2 answers
2k views

algebraic equivalence of divisors

14 votes
1 answer
2k views

What are p-adic period rings?

10 votes
2 answers
2k views

Does the derived category remember the homological dimension?

11 votes
3 answers
2k views

Why is a variety of general type hyperbolic?

12 votes
1 answer
2k views

Cohomological functor from triangulated category

17 votes
3 answers
2k views

What are the auto-equivalences of the category of groups?

14 votes
2 answers
2k views

Can one find the hodge number by counting points over finite fields?

5 votes
1 answer
1k views

Sections of etale morphisms

8 votes
1 answer
1k views

obstruction to smooth lifting of smooth schemes

10 votes
1 answer
976 views

Characterization of schemes whose dualizing complex is perfect

7 votes
6 answers
973 views

Why are the following varieties symplectomorphic?

2 votes
3 answers
935 views

Finitely generated monoids are finitely presented?

14 votes
2 answers
860 views

What's the easiest example of a morphism of topoi that is not from that of a site?

7 votes
8 answers
720 views

What is an example of a function on M_g?

8 votes
1 answer
656 views

Is it possible to do intersection theory in the derived category of a scheme?