2,863 reputation
11433
bio website perso.univ-st-etienne.fr/…
location Saint-Etienne, France
age 33
visits member for 3 years, 6 months
seen 27 mins ago

I am currently a Maître de Conférences in Saint-Étienne, in France. I am particularly interested in Number Theory and Arithmetic Geometry.


2d
comment When complex conjugation lies in the center of a Galois group
You're perfectly right, I had overlooked your assumption while answering. I erased the portion of text in question.
2d
revised When complex conjugation lies in the center of a Galois group
deleted 237 characters in body
2d
awarded  Enlightened
2d
awarded  Nice Answer
2d
answered When complex conjugation lies in the center of a Galois group
Apr
5
answered “frequency” of fields for which the p-adic regulator vanishes (mod p)
Mar
31
answered Structure of $\text{Aut}_R(R[X])$
Mar
28
comment Where to buy premium white chalk in the U.S., like they have at RIMS?
The very sad news, which I got from a Japanese colleague yesterday, is that Rakuten is closing end of March because of some economical issue. So, hurry up!
Mar
25
comment Why no abelian varieties over Z?
@ Emerton: but oddly enough, Khare-Wintenberger need an inductive argument whose basic step relies upon Schoof's work on abelian varieties over number field with few bad places... ;)
Mar
6
reviewed Reject Inverse of a matrix expression
Mar
6
reviewed Approve Averages over integer points of the sphere
Feb
25
comment Why is Class Field Theory the same as Langlands for GL_1?
@Kimball: I have downloaded the notes, but on page 115 you say that there is an isomorphisms between the idèle class group and the Galois group of $K^\text{ab}$, whereas I think you should mod-out by the connected component. This should create some discrepancy between "Galois characters" and "Hecke characters", no?
Feb
24
comment structure of norm one group for quadratic extension of p-adic fields
By definition, $U_E$ are the units, so all its elements are invertible...
Feb
9
reviewed Edit Rational subspaces
Feb
9
revised Rational subspaces
error in latex
Jan
27
reviewed Approve Besse p134 Riemann tensor in dimension 4
Jan
23
comment Is there a Galois correspondence for ring extensions?
Since I do not read russian, this might be the right place where to ask: are you aware of a generalization of the norm in a Galois extension of noncommutative algebras? Of course, if one treats central simple algebras, there is a reduced norm, but I am in a more general setting: $k$ a field, $B/A$ a finite (Galois?) extension of noncommutative $k$-algebras; and would like something like $\mathrm{Norm}_{B/A}\colon B^\times\to A^\times$.
Jan
23
comment Fixed field of the Nebentypus of a newform for $\Gamma_1(N)$
Oh, yes, I was sloppy with $L$ and $F$; thanks anyway.
Jan
23
comment Fixed field of the Nebentypus of a newform for $\Gamma_1(N)$
David, just one question: when you say that $F$ is evidently $\mathbf{Q}(i)$, do you really mean that or simply that it is very much reasonable to guess from the first five coefficients? Of course, this does not affect your argument, but just to know.
Jan
22
reviewed Approve Proof of a cubic equation problem