526 reputation
49
bio website wallenborn.net
location Bonn, Germany
age
visits member for 2 years, 7 months
seen Jul 23 at 20:17

Oct
29
revised Math induction ($n^2 \leq n!$) help please
added 119 characters in body
Oct
29
answered Math induction ($n^2 \leq n!$) help please
Oct
25
comment Diagonalizing a matrix with a symmetric matrix
with "problem I have is that the U i found is not symmetric" you mean that "problem I have is that the U i found is not orthogonal" or not? Beeing symmetric ($A=A^T$) is something different then beeing orthogonal ($A^{-1}=A^T$)
Sep
2
comment A question regarding non archimedean absolute values
I think this argument has circular reasoning in it (the part where you say "consequently the second term cannot contribute") so I did the proof thoroughly in an own answer.
Sep
2
answered A question regarding non archimedean absolute values
Sep
1
awarded  Excavator
Sep
1
revised A question regarding non archimedean absolute values
looked wired without a centered dot in it
Sep
1
suggested suggested edit on A question regarding non archimedean absolute values
Aug
31
accepted equivalence of two definitions of norm equivalence: “$|\cdot|_1=|\cdot|_2^\alpha$” vs. “being a Cauchy sequence is the same for both norms”
Aug
31
comment equivalence of two definitions of norm equivalence: “$|\cdot|_1=|\cdot|_2^\alpha$” vs. “being a Cauchy sequence is the same for both norms”
g thank you very much! I'm not sure about the netiquette here: in a situation like this, should I have edited the mistakes?
Aug
30
comment equivalence of two definitions of norm equivalence: “$|\cdot|_1=|\cdot|_2^\alpha$” vs. “being a Cauchy sequence is the same for both norms”
the $=$-sign after that should also be a $\geq$.
Aug
30
comment equivalence of two definitions of norm equivalence: “$|\cdot|_1=|\cdot|_2^\alpha$” vs. “being a Cauchy sequence is the same for both norms”
In the line after you chose $l$ with $l+2\leq k$ there is a $\leq$ in the middle where (imho) should be an $\geq$.
Aug
30
comment equivalence of two definitions of norm equivalence: “$|\cdot|_1=|\cdot|_2^\alpha$” vs. “being a Cauchy sequence is the same for both norms”
And then I don't get the line with $k\rightarrow\infty$: Do you mean that the relation in the line befor ($m_kv_x+n_kv_y\in[2kR,2(k+1)R)\times(-\infty,-kR)$ holds for all $k$? And then: Why does it hold for all $k$? :-)
Aug
30
awarded  Commentator
Aug
30
comment equivalence of two definitions of norm equivalence: “$|\cdot|_1=|\cdot|_2^\alpha$” vs. “being a Cauchy sequence is the same for both norms”
there is something wrong in the line starting with "is a lattice on $\mathbb{R}^2$: Do you mean for all $p,q\in\mathbb R$ define $v$ and $w$ in the way you did and then use the triangle-inequality?
Aug
29
asked equivalence of two definitions of norm equivalence: “$|\cdot|_1=|\cdot|_2^\alpha$” vs. “being a Cauchy sequence is the same for both norms”
Jul
11
revised $\alpha x^2+\beta y^2=\gamma$ solvable over $\mathbb Q$ iff $ax^2+by^2=z^2$ solvable over $\mathbb Z$ with coprime $x,y,z$?
there was a typo: wrote u insted of v
Jul
11
suggested suggested edit on $\alpha x^2+\beta y^2=\gamma$ solvable over $\mathbb Q$ iff $ax^2+by^2=z^2$ solvable over $\mathbb Z$ with coprime $x,y,z$?
Jul
11
accepted $\alpha x^2+\beta y^2=\gamma$ solvable over $\mathbb Q$ iff $ax^2+by^2=z^2$ solvable over $\mathbb Z$ with coprime $x,y,z$?
Jul
11
asked $\alpha x^2+\beta y^2=\gamma$ solvable over $\mathbb Q$ iff $ax^2+by^2=z^2$ solvable over $\mathbb Z$ with coprime $x,y,z$?