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bio website math.uvic.ca/faculty/aquas
location University of Victoria
age 46
visits member for 3 years, 11 months
seen 5 hours ago
The pic is the phase portrait of a simple "piecewise isometry". Define a map by sliding the two halves of the plane: the top half to the right; the lower half to the left and then rotate. Around each periodic point of the map there's a "periodic island". These are what are in the image...

20h
comment Particular case of every sequence has a Cauchy subsequence?
It's not a matter of whether your question is too easy. It's a matter of whether it belongs on a site for professional mathematicians to discuss their work. This question (and your other ones) do not belong here.
2d
comment Parity of primes
I've noticed that most primes seem to start with a 1 in their base 2 expansion.
2d
answered Parity of primes
Oct
21
comment What should be considered a finite size of an infinite dimensional space?
@Michael: Even if you want linear maps, this just boils down to the cardinality of the basis of the vector space. The interesting question is if you ask about bounded maps with respect to a norm. Then this is really quite subtle.
Oct
21
comment A calculus question
@Anand: I don't think this is right. There are quite easy upper bounds of $1/(c(\log(1/c))^q)$. On $[e,c^{-1/4}]$, you can bound the integrand above by (a multiple of) $r$; on $[c^{-1/4},c^{-1/2}]$ you can bound above by a const. multiple of $r/(\log(1/c))^q$; on $[c^{-1/2},\infty)$, you can bound above by a const multiple of $re^{-cr^2}/(\log(1/c))^q$. Then you can integrate all of these.
Oct
21
comment How to prove $\lim _{ \delta\rightarrow {0}^{+}}\int_{a}^{b} F_{\delta}(x)dx=0 ? $
Hello @nobody. Not getting an answer on MSE (in 17hrs) isn't sufficient qualification to put the question on this site. This is not a mathematical research question. Voting to close.
Oct
20
comment The behavior of series involving special subsets of the prime numbers
So the crudest heuristics suggest that this should be finite for all $k$: if each number $n$ is `prime with probability $1/\log n$', then the probability $n$ belongs to $\mathbb P_k$ is around $2k/(\log n)^2$. Hence you should expect $\sum_{p\in\mathbb P_k}1/p\approx \sum_{n>1} 2k/(n(\log n)^2)<\infty$, and expect that this should grow like $k$. More refined heuristics take into account small factors of $n$ etc. I doubt this would change the expected outcome much.
Oct
20
comment Is there effective algorithm for finding “minimal discovery time” for large graphs?
So you're asking about the cover time (or a variant).
Oct
20
comment A proof from Lang's undergraduate analysis
So if $A=(-1,1)\setminus\{0\}$, then it's a bounded subset of $\mathbb R^1$ and its boundary consists of $\{-1,0,1\}$. On the other hand $\bar A=[-1,1]$, so that its boundary consists of $\{\pm1\}$. Hence, as you suspected it's not true in general that $\partial A=\partial\bar A$. Also, as you suggest, I see no place where the supposed equality of these two sets is used.
Oct
18
comment A calculus question
@Anand: No I mean your expression $c\log(1/c)^qf_q(c)$ converges to something positive as $c\to 0$.
Oct
18
comment A calculus question
@Anand: I agree. I think I was integrating from 1 to $\infty$. I corrected the answer.
Oct
18
revised A calculus question
fix math error
Oct
18
answered A calculus question
Oct
18
comment Fermat's little theorem with smaller powers
This question does not belong on this site.
Oct
18
answered About the regularity of the boundary of a set
Oct
15
comment 1 dimensional flows and phase portraits
I flagged it for a moderator for possible transfer (I'm not sure if this the right course of action, but I have no doubt I'll be set right if this isn't the right thing...)
Oct
15
comment 1 dimensional flows and phase portraits
This isn't a suitable question for this site (which is for research mathematics). You might try math.stackexchange.com
Oct
12
comment Why we mistaken coin toss to be an example of classical probability?
So there's a big difference between tossing a coin and dropping a coin (which is what the cited article is about). I have probably seen 1000 coins tossed in my lifetime, and never seen one land on its edge. If the frequency were anywhere close to that claimed in the posting, many of us would have seen coins land this way.
Oct
12
answered A question regarding Kingman's theorem as described in “Ergodic Theorems” book written by Ulrich Krengel
Oct
12
comment A question regarding Kingman's theorem as described in “Ergodic Theorems” book written by Ulrich Krengel
I possess a copy of that book, and have read a version of Kingman's theorem, but the manner in which you ask the question does not encourage me to dig them out. You are asking about a single inequality. How hard would it be to define the terms in the inequality?