fuglede
Reputation
4,497
Top tag
Next privilege 5,000 Rep.
Approve tag wiki edits
 Nov 18 awarded Nice Answer Oct 23 revised why do odd magic squares have the same rank as their size? added 10 characters in body Oct 19 comment Compute $\partial_t \Gamma_{ij}^k$ under Ricci flow. But say that $\partial_t g_{ij} = 0$ at the point $x = 0$, in our normal coordinate system. Then this does not say much about the value of $\partial_t g_{ij}$ at nearby points, so that in particular, the positional partial derivatives of $\partial_t g_{ij}$ could be non-zero. Oct 19 comment Compute $\partial_t \Gamma_{ij}^k$ under Ricci flow. Hm, no, since again, those properties only hold at a point. It's similar to how you do not have $f''(x) = (f'(x))'$. Oct 19 comment Compute $\partial_t \Gamma_{ij}^k$ under Ricci flow. Well, at the origin of the coordinate system, yes, and the first partial derivatives vanish at that point; see the Wikipedia article. Oct 19 comment Find a positive natural number, $N$ such that $\frac{(n!)^2}{(2n)!}\leq \frac{1}{500} \forall n\geq N$ Remark: This looks rather similar to this question, posted slightly earlier. Oct 19 comment Compute $\partial_t \Gamma_{ij}^k$ under Ricci flow. You seem to be asking if this has something to do with whether or not one can choose normal coordinates, but according to the first line of the proof, this is exactly what is done. Oct 19 answered Solving an inequality involving factorials and an exponent Oct 14 comment Find the range of $f(x)=x/(3x^2−3x)$ What is the domain of the function? The reals except from $0$ and $1$? Oct 14 revised Which one is larger asymptotically? Fixed some formatting Oct 13 revised Disjoint union topology vs Product topology added 83 characters in body Oct 13 revised Disjoint union topology vs Product topology added 130 characters in body Oct 13 answered Disjoint union topology vs Product topology Oct 2 revised Basic question on the behavior of $\varepsilon$ in real analysis Semantics Oct 1 comment Basic question on the behavior of $\varepsilon$ in real analysis Let's try two wildly different examples again. If $\varepsilon = 60$, then $2\varepsilon = 120$, which is bigger than $60$. On the other hand, if $\varepsilon = 1/60$, i.e. pretty small, then $2\varepsilon = 2/60 = 1/30$, which is bigger than $1/60$. No matter what $\varepsilon > 0$ is, $2\varepsilon$ will be bigger. Oct 1 answered Basic question on the behavior of $\varepsilon$ in real analysis Sep 30 comment Is $\mathbb R/R$ a partition of $\mathbb R$ given by some equivalence relation $R$? And that in case that notation is new to OP, this means $x + \mathbb{Z} = \{ x + n \mid n \in \mathbb{Z} \}$. Sep 30 answered Is $\mathbb R/R$ a partition of $\mathbb R$ given by some equivalence relation $R$? Sep 13 comment Find all sets in sigma algebra generated by subsets A, B Note that the sets you found are not necessarily distinct so that there need not be 16 sets. Sep 9 revised Find all sets in sigma algebra generated by subsets A, B added 14 characters in body