Skip to main content

All Questions

Filter by
Sorted by
Tagged with
6 votes
1 answer
424 views

Galois module theory: from global to local

Let $L/\mathbb{Q}$ be a finite Galois extension with Galois group $G$. It is well known that the ring of integers $\mathcal{O}_L$ is free over its associated order $\mathfrak{A}_{L/\mathbb{Q}}=\{x\in \...
Lios's user avatar
  • 213
7 votes
1 answer
1k views

Given $v,w$ primes of $k$, is there $K/k$ so $K_v\cap\Bbb Q^\text{cycl}=K_w\cap\Bbb Q^\text{cycl}=K\cap\Bbb Q^\text{cycl}$?

For any field $k$, let $\mu(k)$ denote the roots of unity in $k$. Now let $k$ be a number field and let $v, w$ be non-archimedean primes of $k$ with distinct residual characteristics. Does there ...
Joel Dodge's user avatar
  • 2,799
4 votes
3 answers
1k views

Why isn't there a structure with two primes?

I don't know whether this question is a bit too vague for MO or not, so feel free to delete it if you see fit. The p-adic integer is defined by taking the inverse limit $\ldots \mathbb{Z} / p^2 \...
abcdxyz's user avatar
  • 2,824
14 votes
3 answers
3k views

Computing (on a computer) higher ramification groups and/or conductors of representations.

I am supervising an undergraduate for a project in which he's going to talk about the relationship between Galois representations and modular forms. We decided we'd figure out a few examples of weight ...
Kevin Buzzard's user avatar