4,106 reputation
21647
bio website bruno.stonek.com
location Montevideo, Uruguay
age 25
visits member for 3 years, 9 months
seen yesterday

Math student in Université Paris 13.


Jul
21
awarded  Good Question
Jul
17
awarded  Favorite Question
Jul
2
awarded  Curious
Jul
2
awarded  Inquisitive
Jun
20
comment On pushouts and mapping cylinders in exact categories
For the prospective reader, I might add that the easy observation that the forgetful functor from $C\mathcal N$ to the category of graded objects over $\mathcal N$ reflects exactness is implicitly being used.
Jun
17
comment On pushouts and mapping cylinders in exact categories
Great! In fact, not too many days ago I managed to solve the problem with help from my supervisor, and I was planning to post it here very soon. I got the same thing as you though I had to use elements to be convinced that the $P$ you define is effectively the pushout, etc. Thanks a lot for your effort on an already old and quite ignored question.
Jun
17
accepted On pushouts and mapping cylinders in exact categories
Jun
16
comment Transitivity of norm and trace for intermediate fields of finite separable extensions
@user157393: done. The separability assumption for the transitivity of the trace is not necessary and not useful either. You can prove it by brute force computation. As for the norm, the result is true for nonseparable extensions but it is much harder to prove. Do you know of a result for norms which might help you out in the separable case (which is the one you care for)?
Jun
16
revised Transitivity of norm and trace for intermediate fields of finite separable extensions
added 1 character in body; edited title
Jun
16
comment Transitivity of norm and trace for intermediate fields of finite separable extensions
The title of your post is hard on the eyes, you could try to make it more readable. Thanks.
Jun
9
accepted Is $\Omega \tilde X \simeq \Omega_0 X$?
May
30
comment Is $\Omega \tilde X \simeq \Omega_0 X$?
Thanks! I'll eagerly read your expanded answer.
May
30
comment Is $\Omega \tilde X \simeq \Omega_0 X$?
Nice! I really like the argument, very clean. Didn't Milnor prove a theorem that loop spaces of CW-complexes have the homotopy type of a CW complex? (I didn't really ever read the actual formal statement), if that's the case then if $X$ is a CW-complex the proof works, and I'm interested in CW complexes so that's that :)
May
30
comment Is $\Omega \tilde X \simeq \Omega_0 X$?
Well ok, this is essentially the statement of the unique path lifting property, disregarding continuity issues, I think. What I still don't really get is why $\Omega_0$ appears.
May
30
asked Is $\Omega \tilde X \simeq \Omega_0 X$?
May
21
awarded  Famous Question
May
21
comment showing exact functors preserve exact sequences (abelian categories, additive functors, and kernels)
+1. This old answer of mine comes to mind.
May
16
comment Equivalent conditions for a preabelian category to be abelian
@t.b.: Almost three years later, I got to the point where I need to get into exact categories (as I seem to be getting into algebraic K-theory...) and your article seems to be the current standard reference. And it is a joy to read, your exposition is wonderful! It's sad that you don't hang around here anymore... Perhaps you will see this comment, and perhaps by the time you see it this question which shouts your name will have been answered already.
May
16
comment On pushouts and mapping cylinders in exact categories
Oh, I wish @t.b. wasn't "on extended leave" from the site...
May
16
asked On pushouts and mapping cylinders in exact categories