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 18238

Algebraic number fields, Algebraic integers, Arithmetic Geometry, Elliptic Curves, Function fields, Local fields, Arithmetic groups, Automorphic forms, zeta functions, $L$-functions, Quadratic forms, Quaternion algebras, Homogenous forms, Class groups, Units, Galois theory, Group cohomology, Étale cohomology, Motives, Class field theory, Iwasawa theory, Modular curves, Shimura varieties, Jacobian varieties, Moduli spaces

4 votes
Accepted

Generalization of Hilbert 94 and capitulation

The answer to both my question is that "adding conductors does not change anything". Olivier has already discussed this for the Principal Ideal Theorem, and for Hilbert 94 this is proven by Suzuki in …
Filippo Alberto Edoardo's user avatar
8 votes
1 answer
1k views

Generalization of Hilbert 94 and capitulation

Let $L/K$ be a finite, cyclic extension of number fields, say with $\mathrm{Gal}(L/K)=G$. In my context $G$ is actually of order $p$, an odd prime number, but let me state my question for every cyclic …
1 vote
Accepted

What are conditions to satisfied by rational prime p so that every prime lying above p is a ...

First of all, as they observe, the assumption that $H(K)/\mathbb{Q}$ is abelian ensures that $H(K)\subseteq\mathbb{Q}(\zeta_{f(K)})$ and not only $K\subseteq\mathbb{Q}(\zeta_{f(K)})$. Also, they work …
Filippo Alberto Edoardo's user avatar
2 votes
Accepted

The kernel of the global class field theory homomorphism

Well, actually the kernel of $\theta$ is perfectly explicit and it is the connected component of the identity in $C_K$: see, for instance, Artin-Tate Class Field Theory, Chapter IX, §1. Theorem 3 ibid …
Filippo Alberto Edoardo's user avatar
6 votes

Ideal classes fixed by the Galois group

As Franz Lemmermeyer suggested, one should consider the so-called Ambigous Class Number Formula: you find it, for instance, in Gras' book "Class Field Theory", II.6.2.3. It says that if $L/K$ is a fi …
Filippo Alberto Edoardo's user avatar
5 votes
0 answers
270 views

Why does the longitude correspond to Frobenius in Arithmetic Topology, and other strange phe...

I am trying to adress Morishita's book Knots and Primes to discover a bit about Arithmetic Topology, but some analogies puzzle me. I know that the correspondence should be addressed with a grain of sa …
0 votes
Accepted

About real abelian number fields

Let $J^{(p)}\subseteq J$ be the subfield fixed by the $p$-Sylow subgroup of $\operatorname{Gal}(J/K)$ which is also the $p$-Sylow subgroup of the (abelian!) group $\operatorname{Gal}(J/\mathbb{Q})$ si …
Filippo Alberto Edoardo's user avatar
1 vote

references on group representation over local fields / a question on an argument of a Ralph ...

Your question has nothing to do with $p$-adic representations, it is a general fact about representations of finite groups. Given a group $\Delta$ and a field $F$ of characteristic $0$ (characteristic …
Filippo Alberto Edoardo's user avatar
2 votes
Accepted

Rationality of trace of endomorphism of Iwasawa-thing

This is not really an answer, just a (very!) long comment. Everything I write is obvious for people working in Iwasawa theory, and I apologize for the trivialities. Let me start by your final paragra …
Filippo Alberto Edoardo's user avatar
2 votes

Computing the relative class group (with Galois action) of relatively large cyclotomic groups

Have you had a look at Schoof's paper The structure of the minus class group of abelian number fields, Séminaire de Théorie des Nombres de Paris, 1988--89? Schoof's idea is to conjecture that the Fitt …
Filippo Alberto Edoardo's user avatar
1 vote
Accepted

Kummer congruences for totally real number fields

I think that the point lies in the difference between a primitive and imprimitive $L$-function. Before entering the details, let me observe that Washington's definition of $p$-adic $L$-functions (as t …
Filippo Alberto Edoardo's user avatar
4 votes
Accepted

Class groups in dihedral extensions - some sort of Spiegelungssatz?

I normally don't like to cite my own work on MO, but this time the preprint arXiv:1803.04064 was written, together with L. Caputo, having the OP's question in mind; and so, first of all, let me thank …
Filippo Alberto Edoardo's user avatar
5 votes
Accepted

Refinement of (classical) Iwasawa main conjecture

There is an answer which follows from Kolyvagin's theory of Euler Systems, and can be found in Theorem 4.4 of K. Rubin, Kolyvagin's System of Gauss Sums, in Arithmetic Algebraic Geometry, van der Gee …
Filippo Alberto Edoardo's user avatar
6 votes
Accepted

The $\ell$- part of the class groups of the $p$-cyclotomic fields

As Keith Conrad observed in his comment, what you are asking about is Washington's theorem which is either in his book, referenced as Theorem 16.12, or in his original paper in Invent. Math. He proved …
David Loeffler's user avatar
6 votes

An elementary, short proof that the group of units of the ring of integers of a number field...

I do not know if the following qualifies as "short" or "elementary": but it does not follow the usual pattern through Minkowski's Convex Body Theorem. Rather, it mimics the classical proof of Mordell– …
Filippo Alberto Edoardo's user avatar

15 30 50 per page