138 reputation
4
bio website az2000.de
location
age 28
visits member for 3 years, 4 months
seen Jan 3 at 11:54

I am postgraduate of RWTH Aachen, Germany and received a M.S. Math and a M.S. CompSci. My main interests are Machine Learning, Neural Networks, Artificial Intelligence, Logic, Automata Theory and Programming Languages. And I'm an enthusiastic hobby programmer with a wide range of side projects, mostly in C++ and Python.


Dec
14
comment How $x^4$ is strictly convex function?
Note that the second derivative is positive almost everywhere. I'm pretty sure that this is also enough to get strict convexity.
Jun
8
accepted writing $M : \Gamma_{n,0} \backslash \Gamma_n$
May
24
revised writing $M : \Gamma_{n,0} \backslash \Gamma_n$
better matrix
May
24
revised writing $M : \Gamma_{n,0} \backslash \Gamma_n$
added 84 characters in body
May
24
revised notation for invariation
added 134 characters in body
May
24
comment How to write presentation of a group?
Why do you write $e_i^2 = 1, e_i e_j = e_j e_i$? Couldn't you just write $e_i \in \mathbb{Z} / 2 \mathbb{Z}$? Or, if you want to have representations, $e_i \in \{0,1\}$? That somewhat seems simpler to me.
May
24
asked notation for invariation
May
24
asked writing $M : \Gamma_{n,0} \backslash \Gamma_n$
May
13
awarded  Scholar
May
13
accepted extended Euclidean (xgcd) in quadratic integer rings
May
13
revised extended Euclidean (xgcd) in quadratic integer rings
added 361 characters in body
May
13
comment extended Euclidean (xgcd) in quadratic integer rings
A bit more generic, where I need that: Given a matrix $M \in \operatorname{Sp}_2(\mathbb{K})$, I want to find $\gamma \in \operatorname{Sp}_2(\mathcal{O})$, $R \in \operatorname{Sp}_2(\mathbb{K})$ such that $M = \gamma \cdot R$ and I want the left lower $2 \times 2$ matrix of $R$ to be zero. In my construction, I heavily depend on the extended Euclidean algorithm.
May
13
comment extended Euclidean (xgcd) in quadratic integer rings
In case it is an Euclidean domain, how would an implementation of the extended Euclidean algorithm look like? I mostly wonder about how to define/implement the division with remainder. -- Also, why would the non-Euclidean but UFD fail there? -- Is it easy to give an example where you cannot find $x,y$ in a non-UFD?
May
13
awarded  Student
May
12
revised extended Euclidean (xgcd) in quadratic integer rings
edited body
May
12
asked extended Euclidean (xgcd) in quadratic integer rings
May
14
awarded  Supporter
Dec
5
comment formal languages: what does R-trivial mean?
@Robin: Haven't you read my first sentence? Again, I quite fail to understand why it is bad to have that copied here.
Dec
4
comment formal languages: what does R-trivial mean?
@Robin: That is for forum-like sites. But I see SE-sites more as QA-sites where it is of value to have as much questions answered as possible.
Dec
4
comment formal languages: what does R-trivial mean?
@Robin: To help people find the question & answer. Is that bad? And still, even if that is bad, why is the question bad then?