Question

Map from $B$-scheme to projective space

score 268 · Answer 1 · 2020-10-22 15:09:29

268

Views

Map from $B$-scheme to projective space

Published on 22 Oct 2020 - 15:09

score 105 · Answer 2 · 2026-03-27 15:07:28

105

Views

Are these rings the same? A detail in the Proj construction

Published on 27 Mar 2026 - 15:07

score 213 · Answer 3 · 2020-11-13 13:17:56

213

Views

Explicit proof that $\mathbb{P}_B^n\cong\mathbb{P}_A^n\times_{\operatorname{Spec}A}\operatorname{Spec} B$

Published on 13 Nov 2020 - 13:17

score 519 · Answer 4 · 2020-11-13 19:01:14

519

Views

Weighted projective space and projective space are isomorphic

Published on 13 Nov 2020 - 19:01

score 1k · Answer 5 · 2020-11-15 04:21:44

1k

Views

Projective scheme over a ring

Published on 15 Nov 2020 - 4:21

score 254 · Answer 6 · 2020-11-18 15:26:14

254

Views

Definition of projectively normal in Harshorne Ex II.5.14

Published on 18 Nov 2020 - 15:26

score 302 · Answer 7 · 2026-03-26 09:50:04

302

Views

How to prove $ ((S\times_A T)(1))_{(f\otimes g)}\cong S(1)_{(f)}\otimes_{S_{(f)}}(S\times_A T)_{(f\otimes g)}\otimes_{T_{(g)}} T(1)_{(g)}$?

Published on 26 Mar 2026 - 9:50

score 263 · Answer 8 · 2026-03-26 14:35:03

263

Views

If a global morphism of sheaves induces isomorphisms on fibers, then is it an isomorphism?

Published on 26 Mar 2026 - 14:35

score 155 · Answer 9 · 2020-12-15 14:22:15

155

Views

If $\mathcal{L}$ is an invertible sheaf on $\mathbb{P}(\mathcal{E})$, then is the restriction to the fibers constant?

Published on 15 Dec 2020 - 14:22

score 126 · Answer 10 · 2026-03-27 15:07:31

126

Views

isomorphic $\operatorname{Proj}(S)$ with nonisomorphic $S$

Published on 27 Mar 2026 - 15:07

score 208 · Answer 11 · 2021-02-04 22:44:31

208

Views

Short Exact Sequence of a Hyperplane in the Projective Space

Published on 04 Feb 2021 - 22:44

score 406 · Answer 12 · 2021-02-05 00:12:21

What is the projective bundle over $(\Bbb P^1\times\Bbb P^1)/(\Bbb Z/2)$ which isn't $\Bbb P(\mathcal{E})$ for some vector bundle $\mathcal{E}$?

score 87 · Answer 13 · 2021-02-11 21:51:20

87

Views

Failure of rigidity for non-proper morphism.

Published on 11 Feb 2021 - 21:51

score 125 · Answer 14 · 2026-03-27 15:05:36

125

Views

Quotient of $ \operatorname{Proj} A$ by the action of a finite group

Published on 27 Mar 2026 - 15:05

score 206 · Answer 15 · 2026-03-26 10:59:37

206

Views

Projection $\pi: \mathbb{P}^n \dashrightarrow \mathbb{P}^{n-1}$ away from center $p$ maps

Published on 26 Mar 2026 - 10:59

List Question

Map from $B$-scheme to projective space

Are these rings the same? A detail in the Proj construction

Explicit proof that $\mathbb{P}_B^n\cong\mathbb{P}_A^n\times_{\operatorname{Spec}A}\operatorname{Spec} B$

Weighted projective space and projective space are isomorphic

Projective scheme over a ring

Definition of projectively normal in Harshorne Ex II.5.14

How to prove $ ((S\times_A T)(1))_{(f\otimes g)}\cong S(1)_{(f)}\otimes_{S_{(f)}}(S\times_A T)_{(f\otimes g)}\otimes_{T_{(g)}} T(1)_{(g)}$?

If a global morphism of sheaves induces isomorphisms on fibers, then is it an isomorphism?

If $\mathcal{L}$ is an invertible sheaf on $\mathbb{P}(\mathcal{E})$, then is the restriction to the fibers constant?

isomorphic $\operatorname{Proj}(S)$ with nonisomorphic $S$

Short Exact Sequence of a Hyperplane in the Projective Space

What is the projective bundle over $(\Bbb P^1\times\Bbb P^1)/(\Bbb Z/2)$ which isn't $\Bbb P(\mathcal{E})$ for some vector bundle $\mathcal{E}$?

Failure of rigidity for non-proper morphism.

Quotient of $ \operatorname{Proj} A$ by the action of a finite group

Projection $\pi: \mathbb{P}^n \dashrightarrow \mathbb{P}^{n-1}$ away from center $p$ maps

Trending Questions

Popular # Hahtags

Popular Questions