User Will Chen

5 votes

0 answers

243 views

Picard-Lefschetz formula for the quotient of a degenerating family of curves by a cyclic group

asked Jul 7, 2022 at 0:47

5 votes

0 answers

175 views

largest subgroup of $Out(\hat{F_2})$ which preserves the Nielsen invariant

asked Aug 29, 2015 at 20:36

5 votes

1 answer

291 views

Abelianization of characteristic quotients of $F_2$

asked Sep 8, 2015 at 16:22

5 votes

1 answer

311 views

are the coarse moduli schemes of finite etale covers of $\mathcal{M}_{1,1}$ smooth?

asked Oct 28, 2015 at 3:17

5 votes

1 answer

306 views

abelian and nonabelian parts of Aut($\widehat{F_2}$)

asked Nov 19, 2015 at 23:59

5 votes

1 answer

735 views

Some help in digesting a paragraph in the introduction of Deligne/Rapoport's "Les Schemas de Modules de Courbes Elliptique"

asked Jul 2, 2012 at 5:01

5 votes

1 answer

383 views

How does a moduli interpretation give an analytic object an algebraic structure?

asked Nov 9, 2012 at 5:03

5 votes

2 answers

2k views

morphisms of affine schemes question

asked Jun 2, 2011 at 17:04

5 votes

2 answers

1k views

trying to understand the support of the sheaf of relative differentials

asked Apr 29, 2012 at 7:21

5 votes

1 answer

1k views

equivalence between katz and classical modular forms

asked Apr 28, 2013 at 21:05

5 votes

0 answers

734 views

questions about the "relative fundamental group" of SGA 1 Expose XIII

asked Jun 18, 2014 at 23:16

5 votes

1 answer

438 views

Do the automorphism groups of $F_2$ and $G$ act transitively on the surjections from $F_2$ to $G$?

asked Mar 21, 2014 at 14:53

4 votes

1 answer

496 views

technical question about a paper on Belyi's theorem

asked May 1, 2012 at 0:13

4 votes

3 answers

372 views

Automorphism of finite groups and Hurwitz spaces

asked Jan 19, 2013 at 23:42

4 votes

1 answer

537 views

Essential simple closed curves on a punctured torus vs those in the torus

asked Jan 26, 2020 at 10:09

4 votes

1 answer

213 views

Are $\overline{\mathbb{Q}}$-models of smooth affine curves over $\mathbb{C}$ with finitely many automorphisms unique?

asked Oct 14, 2017 at 6:20

4 votes

0 answers

174 views

Explicit examples of finite unramified group schemes

asked Jun 11, 2017 at 0:40

4 votes

1 answer

305 views

Are there "primitive" modular functions for $\Gamma(n)$ with Fourier coefficients in $\mathbb{Q}$?

asked May 31, 2017 at 19:15

4 votes

0 answers

185 views

the Yoneda embedding for finite groups and surjections from a free group

asked Oct 31, 2016 at 21:54

4 votes

3 answers

1k views

When can the "homotopy exact sequence" of etale fundamental groups for a smooth curve fail to be exact?

asked Jan 19, 2016 at 22:08

4 votes

0 answers

683 views

About relative normalization in Deligne's definition of a "tangential morphism"

asked Mar 11, 2016 at 0:44

3 votes

1 answer

282 views

Is the normalization of a proper regular minimal model also a proper regular minimal model?

asked Sep 30, 2016 at 22:01

3 votes

0 answers

180 views

Finite groups $G$ such that the primes dividing $|G|$ are exactly the primes dividing $|G^{ab}|$

asked Oct 25, 2016 at 17:34

3 votes

0 answers

217 views

Is the canonical divisor on a minimal arithmetic surface of genus $\ge 1$ linearly equivalent to a purely horizontal effective divisor?

asked Apr 28, 2017 at 23:19

3 votes

0 answers

147 views

Is the quotient of a prestable curve by a finite group always a scheme?

asked Oct 12, 2021 at 19:03

3 votes

0 answers

1k views

Normal crossings divisors vs "relative normal crossings divisor"

asked Aug 1, 2014 at 11:31

3 votes

1 answer

306 views

If $T$ is an $S$ scheme, and $X,Y$ are $T$-schemes, then do the $S$-valued points of $\mathcal{Hom}_T(X,Y)$ have an interpretation?

asked Aug 7, 2014 at 16:21

3 votes

0 answers

379 views

Is a stack that is finite etale over an algebraic stack also algebraic?

asked Jun 22, 2014 at 2:26

3 votes

2 answers

622 views

Elementary question about Isotopy (in the definition of a Teichmuller space)

asked Jun 20, 2013 at 9:35

3 votes

1 answer

385 views

how do automorphisms act on the right in grothendieck's galois theory

asked Nov 13, 2013 at 3:16

Stack Exchange Network

116 Questions

Picard-Lefschetz formula for the quotient of a degenerating family of curves by a cyclic group

largest subgroup of $Out(\hat{F_2})$ which preserves the Nielsen invariant

Abelianization of characteristic quotients of $F_2$

are the coarse moduli schemes of finite etale covers of $\mathcal{M}_{1,1}$ smooth?

abelian and nonabelian parts of Aut($\widehat{F_2}$)

Some help in digesting a paragraph in the introduction of Deligne/Rapoport's "Les Schemas de Modules de Courbes Elliptique"

How does a moduli interpretation give an analytic object an algebraic structure?

morphisms of affine schemes question

trying to understand the support of the sheaf of relative differentials

equivalence between katz and classical modular forms

questions about the "relative fundamental group" of SGA 1 Expose XIII

Do the automorphism groups of $F_2$ and $G$ act transitively on the surjections from $F_2$ to $G$?

technical question about a paper on Belyi's theorem

Automorphism of finite groups and Hurwitz spaces

Essential simple closed curves on a punctured torus vs those in the torus

Are $\overline{\mathbb{Q}}$-models of smooth affine curves over $\mathbb{C}$ with finitely many automorphisms unique?

Explicit examples of finite unramified group schemes

Are there "primitive" modular functions for $\Gamma(n)$ with Fourier coefficients in $\mathbb{Q}$?

the Yoneda embedding for finite groups and surjections from a free group

When can the "homotopy exact sequence" of etale fundamental groups for a smooth curve fail to be exact?

About relative normalization in Deligne's definition of a "tangential morphism"

Is the normalization of a proper regular minimal model also a proper regular minimal model?

Finite groups $G$ such that the primes dividing $|G|$ are exactly the primes dividing $|G^{ab}|$

Is the canonical divisor on a minimal arithmetic surface of genus $\ge 1$ linearly equivalent to a purely horizontal effective divisor?

Is the quotient of a prestable curve by a finite group always a scheme?

Normal crossings divisors vs "relative normal crossings divisor"

If $T$ is an $S$ scheme, and $X,Y$ are $T$-schemes, then do the $S$-valued points of $\mathcal{Hom}_T(X,Y)$ have an interpretation?

Is a stack that is finite etale over an algebraic stack also algebraic?

Elementary question about Isotopy (in the definition of a Teichmuller space)

how do automorphisms act on the right in grothendieck's galois theory