Will Chen's user avatar
Will Chen's user avatar
Will Chen's user avatar
Will Chen
  • Member for 12 years, 10 months
  • Last seen this week
  • New York, NY
7 votes
3 answers
889 views

Do there exist elliptic curves over schemes which have all primes as residue characteristics?

7 votes
0 answers
522 views

Mapping class group action on fundamental group of punctured elliptic curves

7 votes
2 answers
657 views

confounding riddle about fine moduli schemes and twists of elliptic curves

7 votes
3 answers
1k views

moduli interpretations for modular curves

7 votes
6 answers
2k views

Are there noncongruence subgroups (of finite index) of the modular group generated only by 2 or 3 elements?

7 votes
3 answers
431 views

Are non-isomorphic covers of riemann surfaces also generally nonisomorphic as riemann surfaces?

7 votes
1 answer
2k views

Universal covering map from $\mathcal{H}$ to $\mathbb{C}\setminus \mathbb{Z}\oplus i\mathbb{Z}$ (the countably punctured complex plane)

6 votes
1 answer
787 views

Is there an elliptic surface over $Y(1)$?

6 votes
0 answers
608 views

analog for the discriminant of number fields in the function field case?

6 votes
3 answers
2k views

Smooth Models of Hyperelliptic Curves (+ a concrete question)

6 votes
1 answer
400 views

Can you functorially "reconstruct" a branched cover of curves from its etale locus?

6 votes
1 answer
295 views

Is every nonabelian finite simple group a quotient of a triangle group $(a,b,c)$ with $a,b,c$ coprime?

6 votes
4 answers
418 views

Are there examples of families of objects which are canonically isomorphic, but where diagrams of canonical isomorphisms don't commute?

6 votes
1 answer
421 views

Is there a Riemann existence theorem for orbifolds?

6 votes
1 answer
286 views

question about fiber functors and fundamental groups

6 votes
1 answer
410 views

What is known about the functor $G\mapsto k[G]^\times/k^\times$?

6 votes
2 answers
433 views

Torsion points on twists of elliptic curves and products of fine modular curves over $\mathcal{M}_{1,1}$ vs over the $j$-line

6 votes
1 answer
794 views

Does there exist a discrete valuation subring $R$ of $K((t))$ ($K$ a number field) of residue characteristic $p$ with $\mathrm{Frac}(R) = K((t))$?

5 votes
1 answer
178 views

Is the function field of every congruence modular curve generated by $j,j\circ g$ for some $g\in\text{GL}_2(\mathbb{Q})^+$?

5 votes
3 answers
481 views

Can we classify all finite 2-generated groups $G$ such that if $x,y$ generate $G$, then so does $x,yxy^{-1}$?

5 votes
2 answers
471 views

Pulling back the lisse-etale structure sheaf via the inclusion of a point

5 votes
1 answer
430 views

How is a universal deformation ring in a 1-dimensional DM stack related to the complete etale local ring of coarse moduli scheme?

5 votes
1 answer
437 views

Reference for normalization of an algebraic stack?

5 votes
1 answer
154 views

$SL_2$-action on the free lie algebra on a 2-dimensional vector space

5 votes
0 answers
191 views

Relation between potential good reduction of curves and belyi maps

5 votes
0 answers
112 views

Do the "Nielsen" IA-automorphisms of a profinite free group $\widehat{F}$ of rank 2 form a normal subgroup of $\mathrm{Aut}(\widehat{F})$?

5 votes
0 answers
320 views

How can a pro-object of the category of finite etale schemes fail to be a profinite-etale scheme?

5 votes
0 answers
255 views

Is there a geography of Hodge numbers for minimal general type algebraic surfaces?

5 votes
0 answers
243 views

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

5 votes
1 answer
342 views

Lengths of closed geodesics on a flat vs hyperbolic punctured torus