1,497 reputation
515
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location Berlin, Germany
age 26
visits member for 3 years, 4 months
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I got my Master degree in Pure Mathematics in Rome, and now I'm a PhD-student in Berlin.

My main research interest is Arithmetic Geometry, but I'm here mainly because I like to keep an open eye towards a variety of fields in Mathematics!


Jan
14
comment Prove a function is primitive recursive
Welcome to Math.SE! You could have considered the addition of this link to your question: en.wikipedia.org/wiki/Primitive_recursive_function . In specific the paragraph "Addition" in the page above should answer your question. Is it correct?
Jan
12
accepted Computation of a (probably) tricky limit.
Jan
10
comment Computation of a (probably) tricky limit.
@Marek Thank you very much! I unzipped your comment and you`re totally right (there is still a factor 2 missing, but I'm confident I'll find it once reviewing the computation)! If you want to put it as an answer I will accept and upvote it as soon as possible! :)
Jan
10
revised Computation of a (probably) tricky limit.
edited body
Jan
10
comment Evaluate a double infinite summation
Where does this problem come from? Are you familiar with the notion of Eisenstein series? en.wikipedia.org/wiki/Eisenstein_series It seems quite close to it. But I don't see straight away any explicit relation between the two. If you could provide some more details we could help you better.
Jan
10
comment Evaluate a double infinite summation
What is your question?
Jan
10
comment What is $\operatorname{Ext}_{\mathbb{Z}} (\mathbb{Z}/m\mathbb{Z},\mathbb{Z}/n\mathbb{Z})$?
Are you looking at $\mathbb{Z}/m\mathbb{Z}$ and $\mathbb{Z}/n\mathbb{Z}$ as $\mathbb{Z}$-modules?
Jan
10
revised Computation of a (probably) tricky limit.
added 10 characters in body
Jan
10
asked Computation of a (probably) tricky limit.
Dec
5
comment Sheaf of Ramification Divisor - Hurwitz Formula
The first claim I cited is in Row 2 of the Proof. The second is in Row 6.
Dec
5
comment Sheaf of Ramification Divisor - Hurwitz Formula
Ok, I see! Now I understand the question. :) It looks tough, because it seems to be in open contradiction with the claim he makes a few rows above and which I reported. I'm gonna think about it!
Dec
5
comment Sheaf of Ramification Divisor - Hurwitz Formula
I don't see where is he making such a claim. It looks that he claims $\mathcal{O}_R \simeq \Omega_{X/Y}$ and $f^*\Omega_Y \otimes \Omega_X^{-1} \simeq \mathcal{L}(-R)$. Am I missing something obvious?
Nov
26
comment Equivalence of definition for polarized K3
Thank you very much, now I see it! Unfortunately I didn't encounter the Lefschetz decomposition while googling around. I have a stupid follow up question: "Do all the polarizations of an algebraic K3 surface arise as intersection pairing with signs changed?". On one hand I would say no, because there are polarizable non-algebraic K3s. But on the other hand this would contradict the choice of a polarized algebraic K3 as a pair $(X,\omega)$ for $\omega$ ample. Again I'm a bit confused. Thank you! :)
Nov
26
accepted Equivalence of definition for polarized K3
Nov
26
revised Equivalence of definition for polarized K3
added 2 characters in body
Nov
26
asked Equivalence of definition for polarized K3
Nov
23
comment Problem on finding Geodesics on a surface
In your question there are two questions. What is the one which gives you troubles?
Nov
13
revised Trouble understanding equivalence relations and equivalence classes…anyone care to explain?
deleted 6 characters in body
Nov
13
revised Trouble understanding equivalence relations and equivalence classes…anyone care to explain?
added 498 characters in body
Nov
13
answered Trouble understanding equivalence relations and equivalence classes…anyone care to explain?