Bernie's user avatar
Bernie's user avatar
Bernie's user avatar
Bernie
  • Member for 9 years
  • Last seen more than 1 year ago
6 votes
1 answer
241 views

Are there curves of genus 2 with real multiplication by a non-maximal order?

5 votes
1 answer
270 views

Are there primitive quartic CM fields whose norms of units give all totally positive units of the real quadratic subfield?

4 votes
0 answers
466 views

Is the Gysin map in etale cohomology compatible with taking function fields?

4 votes
0 answers
187 views

Can Kummer surfaces coming from the same abelian surface be Cremona equivalent / isomorphic?

4 votes
1 answer
225 views

Existence of regular conic bundles with a given discriminant divisor

4 votes
0 answers
314 views

Modules over an Azumaya algebra and modules over the associated Brauer-Severi variety

4 votes
1 answer
243 views

Can relative flatness of a sheaf be tested using (faithfully) flat morphisms?

4 votes
1 answer
304 views

Relative tangent bundle of a twisted Grassmann variety

3 votes
0 answers
267 views

Can one construct the GIT quotient of a projective bundle?

3 votes
2 answers
370 views

Is this quotient of a threefold known? What are its singularities?

3 votes
1 answer
361 views

What is known about the cohomology of the relative tangent bundle on a conic bundle?

3 votes
0 answers
141 views

Which blow ups in the base of a conic bundle preserve the "standard" condition?

3 votes
0 answers
321 views

Which sheaves on a projective bundle are flat over the base scheme?

3 votes
0 answers
262 views

Can one control the ramification of a Brauer class under birational morphisms?

3 votes
0 answers
277 views

How much information is encoded in the Jacobian-Kummer K3 surface of a curve of genus two?

3 votes
1 answer
100 views

Why does the variety of ideals in this quaternion type algebra have a non-reduced structure?

3 votes
0 answers
145 views

Moduli space with exceptional Mukai vector and tangent spaces at strictly semistable bundles

2 votes
1 answer
212 views

What finite groups are stabilizers in Kirwan's desingularization construction?

2 votes
2 answers
580 views

Canonical (tautological) section of a family of sheaves

2 votes
0 answers
202 views

Surjectivity locus of a morphism of families of sheaves

2 votes
0 answers
73 views

If a subgroup H of a finite group G acts freely on a variety, can the G-Hilbert scheme be computed by iteration?

1 vote
0 answers
166 views

Are two conic bundles birational, if their bases are birational via a map preserving the associated quaternion algebras?

1 vote
1 answer
484 views

Can one drop the locally free assumption in projection formula on a projective bundle?

1 vote
1 answer
251 views

About the canonical morphism from $f^{*}f_{*}f^{*}F$ to $f^{*}F$

1 vote
1 answer
177 views

How to test if these two threefolds are birationally equivalent?

0 votes
0 answers
80 views

A quaternion x generates a left ideal of rank 2 if and only if x, ix and jx are linearly dependent?

0 votes
1 answer
146 views

Behaviour of (principal) polarizations of (singular) surfaces under birational maps

0 votes
1 answer
109 views

How to find ideals of finite length in a power series ring with special properties?