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00:00 - 18:0018:00 - 00:00

00:18
Fanatic badge! 115 days of me here.
People, can someone tell me if I was painful a guy or somesuch?
I have no idea about what do you mean :)
Oh, forget it then.
:D
everything is ok, I think people here appreciate you as a user
at least in this chat
@Ilya Thank you for the compliment. :)
01:11
@Kannappan, interested in another group theory question?
@AntonioVargas Shoot. I'd like it. :)
I'm trying to understand the proof in this answer that $A_5 = \langle(1\,2\,3),(1\,2\,3\,4\,5)\rangle$.
He says at the end that the index is at most 4, and hence must be 1, but I don't see why it can't be 3 or 4.
And I don't understand why he showed that $A_5 \leq S_i$ for some $i \geq 5$...
His proof is to show that a subgroup of index $i$ in $A_5$ embeds into $S_i$... Then, show that when $H=\langle(123), (12345) \rangle$, you actually have $H=A_5$.
Oh, I completely forgot that $i$ was the index of the subgroup. Yes, that makes sense. Thanks :)
So, that result is not important here...but bcomes useful when you choose your $H$.
And the index should divide the order of the group.
Your subgroup $H$ can have order 15, 45, and so on....
01:21
I was missing the fact that we were assuming $i>1$ and concluding $i\geq 5$ and $i \leq 4$ as a contradiction.
Right, you have a much simpler way there.
I was thinking about $|H|$.
@AntonioVargas Nice! :)
Hi @Ben
@Kannappan It's hard to decide whether I'm studying or procrastinating by looking through Math.SE questions tonight...
@AntonioVargas You were studying. :-)
Seriously, how would reading through some answers be anything if not enlightening?
Yes, that's how I'm convincing myself.
01:43
rehearsing presentation makes me crazy :)
I have 1.5 more hours though
Good luck with the presentation. ^@Ilya
thank you :)
@Ilya What are you presenting?
@Antonio: my paper at HSCC'12
01:58
@Antonio: no
@Ilya Very cool. I hope it goes well :)
@AntonioVargas me too :)
 
1 hour later…
03:25
Hi All of You.
Good time of the day....
Hi @JM
I wonder if you create these gravatars on a daily basis...:)
04:00
Let $X$ be a compact topological space, and let $\{C_{i}\}_{i\in\mathbb{Z}_{+}}$ be
a collection of nonempty closed sets in $X$ satisfying $C_{i+1}\subset C_{i}$ for
each $i\in\mathbb{Z}_{+}$. Prove that $\bigcap_{i=1}^{\infty}C_{i}\neq\emptyset$.
Do I really need to use the fact that the sets $C_{i}$ are closed?
I want to argue by contradiction, but it seems a little too easy.
04:23
@KannappanSampath hi, nice to see you in chat. When did you return?
Hi @Srivatsan
Yesterday, I came in to do math. I don't talk anything other than Math here...
Rob
Rob
Math is life.
Some chat users annoy me so much.
Rob
Rob
Life is math.
Anyway, how are you doing, and how is the weather at Chennai @Srivatsan
04:29
@KannappanSampath I see. :) Anyway, that was quite clear from the chat transcripts (around the time you left the chatroom)
@KannappanSampath chennai weather is still ok, but it's getting warmer.
Hmm, must. resist. temptation. to. mention. names.
Rob
Rob
@anon Hi.
hey
yo
Rob
Rob
04:32
Whatz up?
I will be in Bengaluru soon BTW, Kannappan.
@Srivatsan Exciting. When, if it's decided? =)
And, I have exams from April 30 to May 9. May 11 and onwards, I am in Chennai. Keeping the fingers crossed, so we are not complementary there.
I leave tomorrow, so our stays are not quite complementary.
Nice!!!!
Good. When do we meet then? :-)
(Smiley truncation hurts.)
@KannappanSampath Yes, sure. I will be there for a few months, my availability is not a big constraint. We can agree on any evening and we could meet. Perhaps next week (allowing myself a little time to settle down).
04:40
@Srivatsan Seems ideal to me as well. :-)
But, I'll let you pick an evening. :-)
(Perhaps, you can take time to decide too.)
These questions seem to share a common theme.
Indeed.
@AntonioVargas Binomial sums could be the theme.
@Srivatsan It is likely!
Well, what I said was quite obvious. What I really meant was: binomial sums come up manywhere (e.g., central limit theorems).
04:44
BTW, if someone happens to know a place where Herstein's Non-Commutative rings reside in pdf or djvu, please hint me about that. :)
Interesting. I haven't had much experience with ones involving factors like $(2k-n)^p$.
@KannappanSampath Right, we'll decide some other time. :)
@Srivatsan :-) Knew that.
@KannappanSampath Not sure how :)
I tend to postpone decisions till they make themselves. =)
@Srivatsan Me neither. Just a feeling and it clicks. :-)
BTW, @Srivatsan, to keep you aware, we have had posts from ongoing contest questions overflowing..
04:48
^ which contest(s)?
Purple Math contest or some such...It is supposed to be held online and you know the rest of the story...
Ah, :)
Anyway, gtg now: a few last minute shopping and arrangements :).
Hmph, I thought you'll stay longer.
Anyway, bye for now. See you soon. :) Take care @Srivatsan
leo
leo
05:13
hi
Hi, read your answer there @leo
+1 there. good.
leo
leo
@KannappanSampath groups one?
leo
leo
thanks :-)
Hi @Dylan How are you?
05:18
Hi @KannappanSampath.
06:17
Wikipedia: "The problem of their multiplicity [eigenvalues of the DFT matrix] was solved by McClellan and Parks (1972), although it was later shown to have been equivalent to a problem solved by Gauss. Naturally.
Heh heh.
07:01
Morning.
Rob
Rob
Hello.
Here is a pigeon hurt and bleeding from its head...What is first aid I'd do?
Bleeding is severe AND to save the bird, I'd have to do something. I have never helped a bird. Is there a SE site that helps me with an answer?
@KannappanSampath Take it to the next vet.
But, I am 1 hour away from a vet.
What does the wound look like?
07:08
It is being attacked by another animal or some thing as a prey. So, I am trying to see to it that this does not happen by standing by the bird.
Well will the thing stop bleeding on its own or do you have to do something?
I think it will stop but it bleeds badly.
I'd take a box put some soft stuff in it and then put her in the box and take her home.
@MattN OK. Will do.
phew, I've done my presentation
07:10
That's what I always do : )
@Ilya Congratulations : )
Rob
Rob
@Ilya How did the presentation go?
thanks, got some questions and nice discussions
@MattN: how are you?
@Ilya I'm great, thank you : ) How are you?
Finally, I managed to find an enthusiast who I believe will take this bird to safety.
fine now, thanks
although China is not the best place, even Beijing
07:15
He is a nearby blue cross member and assures me, he will take it to avian specialist.
e.g. Internet is just crazy
@KannappanSampath I'd never trust random strangers...
@KannappanSampath what happened to an animal?
@Ilya It was bleeding. It stopped now. So, I just washed off the wound with cold water and it is OK now.
@Ilya You shouldn't use the internet you should explore Beijing : )
07:17
@MattN didn't appear in my plans
@MattN But, he showed me his card, and I let him take the bird. : (
@KannappanSampath Well well. I'm quite sure he'll just twist her neck once he disappears out of sight (around the next corner). That's what people are like.
But she might have died anyway...
@Ilya : )
And I'll explore some maths now : ) See you later.
Hmph! .... I'd like the bird to live. :/
see ya
@MattN Later Matt.
Rob
Rob
07:19
Did you get any revealing questions at the presentation?
@MattN: that's what you call exploring some math?
Hi @robjohn You have not been around for some time. How are you?
@MattN On the question/ or the answer?
@KannappanSampath which answer do you expect from RobJohn at 2.30 am? :)
@Ilya Well, sorry if should not ask. But, I'd think someone is always well, except on some occassions.
@KannappanSampath pretty good. I've been working all day. I need to get back soon, but I needed to check in :-)
@Ilya it's 12:30 AM :-)
07:39
Good. You should catch some sleep then.
@robjohn: sorry, Chinese time puzzled me
@KannappanSampath not until I finish what needs to be finished
@Ilya That's right, I remember you made a comment about being across the Pacific. I asked where you were, but I never saw a reply. It doesn't mean you didn't reply. :-)
@robjohn Good luck with that. Hope you'll finish it soon and well enough. :)
@KannappanSampath I hope so, too.
@robjohn I think I didn't since I never saw your question :) It doesn't mean you didn't ask :-p
07:44
2 days ago, by robjohn
@Ilya Where are you?
:-)
@robjohn currently, in Beijing. Leaving in 20 hours
@Ilya were you there for an event?
Conference on Hybrid Systems: Computation and Control
@Ilya Cool! (possible racial comment removed)
Rob
Rob
LOL
08:08
@Robjohn: are you here?
08:25
@anon You know Gauss was such a hoarder... :)
@KannappanSampath No, I have a large backlog of unreleased artwork...
Rob
Rob
Newton also, from what I've read :D
@JM :-) Amusing artwork though.
08:41
@KannappanSampath The question.
Hello Great Balls of Fire!
I thought it was genuine,
@MattN Yes, I chose this gravatar precisely to provoke that pun... :)
JM has turned into a ladybug.
(Also, hi)
@anon A ladybird would be more red than orange I think... :)
A spherical ladybug.
08:44
@JM Strangely it looks just like the marble I thought I'd lost...
@anon I read "ladyboy" at first.
@MattN Maybe a sign you should lay off the pron ;-)
@MattN They're both flamboyant, but in different ways...
09:10
Just answered an LHF...
...
...
@anon What the heck...I cannot parse that piece of English!
!!!I am not alone.!!!
@KannappanSampath Of course not; there are tiny beings living inside your system...
09:19
@JM Oh well, yes.
Just realized I made a "your"/"you're" typo on the mainsite, and it was upvoted. ARGH.
@anon the essence was right! :P
But, I did not upvote.
Quite a few LHFs today. feeling ashamed.
@Kanna: Where do you think users get most of their rep?
@anon from writing beautiful answers ...
HAHAHAHA no.
Well, I should say most users.
09:32
@KannappanSampath Pfft, if that were true, I'd have at least one-and-a-half times more rep than what I now have... :)
@JM :) I know. But, some people are not that good when it comes to voting. They vote without rationale.
I usually upvote simple answers iff they are well-written.
@KannappanSampath I've long settled on the belief that most people vote things for giggles, not necessarily because they read and understood the answer...
@JM I am not one of those people....
I remember Asaf saying he believes that it is likely that less than half of the people who voted his blockbusters actually read them in full.
@KannappanSampath In which case, you are a good man. :)
I admitted I did not fully read his answer to my question :-D
(It uses too many things for me to look up that I never feel like doing..)
(Place = absolute value.)
09:38
I rarely upvote going by someone's name. For instance, I know that a post certainly deserves more credit; then I upvote that post if it comes from an user I know. Or if someone whose compliments matter says, that is a nice answer , then...
Hey guys :D
(and girls)
sup random person
I need some help :)
naturally :)
8-9 th grade maths
anywho
09:40
uh-oh, it's a 13-year-old!
but go on.
A man is 42 years old and his son is 12 years old . In how many years will the age of the son be half the age of the man at that time :D
Linear Equations :D
I do realise its summer vacation but I have these classes
@AmithKK: Let's make the number you seek into a variable, say x. Now what is the statement "in x years the age of the son will be half the age of the man" in an equation?
And my motherboard's broken.
Give me a sec
kbd prob
12=1/2*42
That says the sons current age (12) is half of the man's current age (42).
What is the son's age in x years?
And what is the man's age in x years?
12+x
42+x
09:47
Right. Now what's the equation you want?
12+x=1/2*42+x
right?
don't forget your parentheses!
yeah :D
<3
12+x=1/2*(42+x).
not much of a math guy :P
More of a linux guy
09:49
Asaf was a linux guy, but he doesn't hang in chat here any more.
@AmithKK Still, you should keep parentheses in mind. :) Think of what happens if you misplace a delimiter while writing a program.
Ok, 14 sums down.... 4 to go :)
@J.M. I do not underestimate the power of the mighty parenthesis :D
The SE guys should make an app for the droid
the WebUI is a bit flimsy
I have another sum bugging me :P
Seems to be related to Speed=S/t
s = d / t
as long as speed is constant
Gee, and I was about to ask what "sistance" means...
A man completed a trip of 136km's in 8 hours.Some parts f the trip was covered at 15km/hr and the remaining at 18km/hr.Find the part of the trip that was covered at 18km/h
@anon its S in our physics textbook
they dont seem to like D
09:57
obviously the solution is to burn it
I really shouldnt be disturbing you guys :D
Have a good day everyone
Cya
I was enjoying that conversation while typing my answer.
Real-time convo updates, wooo!
@JM I wonder if the OP gets confused by two people with the same name =)
Don't remind me of the Davids...
10:08
"How can you be Michael? I met a different person with that name last week..."
"I named all my kids 'David'."
"But what if you want to call just one of them?"
"Oh, I just use their last names..."
@JM (On a serious note:) I guess that the OP is confused because she/he thinks that the two definitions are different "forms" of the same object, while in fact they are altogether different. The terminology does not help the matter either (normalised form vs. unnormalised form).
Let the TeX gods smite me for using \color{White}X for cheap extra vertical spacing between lines in {cases}...
@anon Well, it is cheating... :)
Why not \, or \; or something like that?
oops, it doesn't work for vertical space.
10:12
switched horizontal with vertical mentally there
@Srivatsan Reminds me of the time I was ragging at this guy for not saying at once that he was using degrees instead of radians in his trigonometric functions...
what the hell...why so many problems in probability?
All, those transformations stuff....
@KannappanSampath Why, you thought they weren't that likely to be asked?
@JM I mean... first and second course in probability is a triviality. You are looking at simple stuff. No measure theory. Nothing difficult to bang your head...
10:17
@KannappanSampath What does a second course in prob. cover?
@Srivatsan those continuous random variables; transformations; continuous random vectors; convergence modes in Random variables.
@KannappanSampath Ok
(Optionally, one does cover Markov chains, and some instructors choose to cover Poisson processes and Brownian motion. I agree these are non-trivial in some sense.)
We are being taught Markov and poisson and hinted that Brownian exists.
@Srivatsan Another thing you might like: I asked several math related TeX questions of TeX. SX. You might like some of them too.
@KannappanSampath Ah, ok. I will go through them shortly
@Srivatsan Sure. If somee thing particularly interests you, please let me know. : D
10:27
Right. The power should be out any minute, see you later.
Later @Sri
10:58
Hi @JM. I have a silly question about a linear algebra proof. Can you help me clear that up?
11:09
@KannappanSampath Let's see what I can do...
I am trying to prove that: for an operator $T$ on $\Bbb C^n$, a subspace $S$ is $T^\ast$ invariant if and only if $S^\perp$ is $T$ invariant.
So, the argument I get for $\Leftarrow$ is that, $\langle A^\ast x, y \rangle=0$ for all $y \in S^\perp$.
Oh dear, subspaces... I'm a bit hazy on those, I'm afraid...
@JM :' ( Hmph, sad.
Hello!
Hi @ymar
(I have not slept yet. :))
11:15
I've just woken up. It's 1pm...
And, your mail to my institute mail server reached me an hour later...Hi there ...
@ymar Huf! You should eat something now. Refresh yourself and all that...
I'll wait with the eating for dinner. :)
Have you been looking at those books?
11:36
Ah, sometimes the long and winding route can be fun...
@KannappanSampath And which of them seems the most useful?
12:05
OK, now I am here more permanently.
I like Shilov.
@ymar the ping. (Sorry had to be away.)
I thought you might. :)
The Dieudonne is postponed for holidays.
I've asked the question we were talking about on main: math.stackexchange.com/questions/133883/…
I'm going to take a shower. See you!
@ymar Your question is very clear. I have not ruled out all of those examples as yet. I am a lazy fellow trying to figure out more and more about Jordan blocks and less and less about those fields. : (
+1 for that question.
@ymar Sure, see you around later.
12:49
hi
Hello!
13:04
Hi
I require some help in perm. and combination
What is the problem?
the number of ways in which m+n things can be divided in to two groups , containing m and n things , where m=n
the solution is = 2 (m!) / (m!*m!*2!) , now I'm unable to understand where the heck does 2! comes in denominator?
I don't think this formula is correct...
Are you sure it's not (2m)! in the numerator?
@ymar hmmm you seem right , parenthesis are missing in formula, so might be I interpreted it incorrectly
But then 2! in the denominator still doesn't seem to make sense.
13:18
neither to me :(
So you have 2m elements.
You want to know in how many ways you can halve this set, right?
@ymar I'm more interested in knowing what is that 2! doing in denominator?
Yeah, but I'm asking if I understood the problem you have to solve.
@ymar yes correct :)
OK, so to halve the set with 2m elements, you need to choose m of them.
Oh, wait!
:)
The formula is correct.
So again, you need to choose m elements out of 2m elements, right?
13:23
@ymar ummm I thought so :P
@ymar yes , that becomes 2m C m
In how many ways can you do that?
yes.
$\binom {2m}{m}=\frac{(2m)!}{m!\cdot m!}$
can you see the formula?
OK. But now you've counted every "halving" twice. Do you see why?
@ymar But now you've counted every "halving" twice , can you simplify this sentence ? I'm non english guy
me neither :)
We're counting ways in which we can halve a 2m-element set.
13:30
@ymar ok , so did we count twice?
Yes, take a look at this example.
Take the set {1,2,3,4}.
What we did was choose 2 of them.
Say {1,2}
But later we also count {3,4}
aah, but how is that a problem?
An even simpler example.
Let's take the set {1,2}
In how many ways can you halve this set?
Exactly.
13:34
aah , now got the problem
:)
So in original problem , once we divided the set , we were counting 2 instead of one
Yes, we counted every way of halving the set twice, because we distinguished between the pairs of halves (A,B) and (B,A).
@ymar Thanks a lot , I really appreciate the help :)
The set {1,2} can be halved into {1} and {2}. But it doesn't matter whether we take {1} first or {2} first.
You're welcome. :)
Is everything clear now?
13:39
@ymar yes , thanks :)
OK :)
14:20
I'm sitting in some seminar on Riesz spaces.
15:01
Good day, everybody! Does anybody know something about Gauss-Markov estimates?
@Jonas Still in that seminar?
@Nimza Hi.
15:52
Hi @Mariano
Hope my recent answers are blooperless and I can sleep without being dragged into downvoting frenzy!!!
Someone telling me my recent answers look OK will get a choclolate box from me. B'coz, they are helping me go to bed.
Bye people. I should sleep now. No chocolate boxes for any of you.
16:15
@Nimza what are they? ah, statistics...
 
1 hour later…
17:25
Heyyy
Rob
Rob
@RajeshD Hey
I am stuck with this HIMYM thing !
Rob
Rob
HIMYM?
leo
leo
hi
Rob
Rob
Hi.
leo
leo
17:36
I don't understand. This answer is wrong and have 2 upvotes. This answer is correct (I hope, at least nobody says that isn't) and have no upvotes.
17:55
votes do not measure correctness
in any case, if one of the answers is wrong it would be useful for you to edit it and say so explicitly at the top ;)
leo
leo
@MarianoSuárezAlvarez I'm about to delete it
you don't reall yhave to delete it
00:00 - 18:0018:00 - 00:00

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