Skip to main content
Search type Search syntax
Tags [tag]
Exact "words here"
Author user:1234
user:me (yours)
Score score:3 (3+)
score:0 (none)
Answers answers:3 (3+)
answers:0 (none)
isaccepted:yes
hasaccepted:no
inquestion:1234
Views views:250
Code code:"if (foo != bar)"
Sections title:apples
body:"apples oranges"
URL url:"*.example.com"
Saves in:saves
Status closed:yes
duplicate:no
migrated:no
wiki:no
Types is:question
is:answer
Exclude -[tag]
-apples
For more details on advanced search visit our help page
Results tagged with
Search options not deleted user 128825

Algebraic varieties, stacks, sheaves, schemes, moduli spaces, complex geometry, quantum cohomology.

11 votes

Is $\operatorname{Spec}( \mathbb Q[x_1\ldots,x_n])$ simply connected space?

$\mathrm{Spec}(\mathbb{Q}[x_1,...,x_n])=\mathbb{A}^n_\mathbb{Q}$ is not étale simply connected as $\widehat{\pi}_1(\mathbb{A}^n_\mathbb{Q})=\mathrm{Gal}(\overline{\mathbb{Q}}/\mathbb{Q})$, but $\mathr …
nGroupoid's user avatar
  • 303
10 votes

Spec Z is simply connected space?

Here's a nice way to see that $\mathrm{Spec}(\mathbb{Z})$ is étale simply connected. Since $\mathrm{Spec}(\mathbb{Z})$ is a normal scheme every connected finite étale cover of $\mathrm{Spec}(\mathbb{Z …
nGroupoid's user avatar
  • 303
5 votes
Accepted

What is the spectral interpretation of the arithmetic zeta function?

First, it's worth mentioning that the above theorem refers to the (local) Hasse-Weil zeta function of a scheme $X$ of finite type over $\mathbb{F}_q$ rather than the arithmetic zeta function of a sche …
nGroupoid's user avatar
  • 303
3 votes

Galois categories for topological spaces?

To expand on Niels' answer: given a connected semilocally simply connected topological space $X$ and a point $x\in X$, the fiber functor $F_x:\mathrm{Cov}_X\rightarrow\mathrm{Set}$ from the category o …
nGroupoid's user avatar
  • 303