The h Bar

Secret

10:14

Pop sci explanation of entanglement = bad

there is no "instantly"
The entangled pair is basically one object

when you measure it and it projected into one of the eigenstates, said eigenstate involve both A and B, thus if one is red, the other must be green (correlations)

It is not that the state is determined from the start except we don't know it
Rather it is the probability amplitude that is determined by the two systems interacting some time in the past

seriously old news

Secret

10:38

How your gameplay helps ScienceAtHome build a quantum computer

►

This is why I think accurate visualisation is so important
Same equations, same problem, different presentation

One is formal and rigorous
Another is not as formal, but accurate enough and fun to play with

and when playing become research, it is win win

Perhaps we should write a program that simulate particle physics and QFT problems, and let the citizen scientist to solve it for us?

Slereah

11:04

0

Q: quantum entanglement and its application in migratory birds

Explain the concept of quantum entanglement.Also explain its application in migratory birds. i know that it also has a relation with the magnetic field of the earth.

best question

Sᴋᴜʟʟ ᴘᴇᴛʀᴏʟ

go for it

i think i saw a ted talk on that once...

Physics Meta

1

Q: How can we encourage more Astrophysicists on SE?

I'm a relatively new user and have already noticed a lack of users with interest in Astrophysics, compared to Quantum Mechanics or Quantum Field Theory. I have interest in these more popular areas as well, so I am still enjoying the site, but it would be great to see more Astrophysicists on here!...

discussion

Sᴋᴜʟʟ ᴘᴇᴛʀᴏʟ

@0celo7 how could you even THINK that i would want you suspended? btw, you're not the first person to post a "star this if you hate me" message.

in Mathematics, Feb 16 '12 at 8:38, by Skullpatrol

To all those people who think Skullpatrol is annoying enough to be removed from this chat room: star this message (if the count is 3 or more I will not return) Thank you.

Slereah

11:54

.Hm

How do you prove the Pauli Fierz identity without using any representation

$\sigma^\mu_{\alpha\dot\alpha}\sigma_{\mu\beta\dot\beta} = 2 \varepsilon_{\alpha\beta} \varepsilon_{\dot\alpha\dot\beta} $

ACuriousMind

@Slereah Um...It's a specific statement about the Pauli matrices in a chosen representation (the spinor one), is it not?

Slereah

Not quite sure

ACuriousMind

I'm pretty sure

Slereah

Though really it would be nice if there was a way to do it without doing it component by component

th.physik.uni-bonn.de/th/people/odakin/exerc/…

This bit claims it follows directly from the properties

Oh wait, maybe...

ACuriousMind

@Slereah Note that you can't even formulate the r.h.s. of the identity in a representation-independent way - at least I don't see how

Slereah

12:05

$\sigma^\mu_{\alpha\dot\alpha}\sigma_{\mu\beta\dot\beta} \epsilon^{\alpha\beta} = \sigma^{\mu\beta}_{\dot\alpha}\sigma_{\mu\beta\dot\beta} = nI$

And on the other side...

ACuriousMind

(I must admit that I actually have no clue how the dotted/undotted notation works :D)

Slereah

$2 \varepsilon_{\alpha\beta}\varepsilon^{\alpha\beta}\varepsilon_{\dot\alpha\dot\be‌ta} = 4 \varepsilon_{\dot\alpha\dot\beta}$

fuark

I don't know

@ACuriousMind They are components in the spinor space

ACuriousMind

Well, duh :P

Slereah

There are four spaces

The basic spinor space

Dual spinor space

And then you can conjugate them

$\varepsilon$ is the metric of the spinor space

While $\sigma$ is a map from spinors to vectors

ACuriousMind

See, that's why I hate physicists' terminology. "Basic spinor space" is the space of right-handed Weyl spinors?

Slereah

12:08

Hm

Been a while

ACuriousMind

Okay, let's start with the simplest thing: Is "basic spinor space" 2 or 4 dimensional?

Slereah

Let's check

IIRC it is $\Bbb C^2$, yes

And one is the left handed while the other is the right handed one

Well, not quite

I think it's something like $\psi_R = \psi_\alpha$ while $\psi_L = \psi^{\dot\alpha}$

ACuriousMind

That's horrible, I now remember why I never bothered to learn that notation :D

Slereah

yeah I think that's basically it

That way you get the correct $\psi_L^* \psi_R \in \Bbb R$

And the dagger maps upper to lower indices via $\varepsilon$

So more like $\psi_L^\dagger \psi_R = (\psi_{\dot\alpha})^* \varepsilon^{\alpha\beta} \psi_{\beta}$

At its core it's basically like differential geometry

there are just more vector spaces and complex numbers

yuggib

12:25

you should all learn non-commutative integration and non-commutative probability theory...it's so fun ;-)

Slereah

is non-commutative integration the Grassman one

yuggib

especially you @0celo7... (I know you can't reply X-D)

@Slereah nope

it's more on this spirit

and non commutative probability is not so dissimilar

it's like doing standard integration and probability, but everything is automatically quantum

Slereah

Is that similar to like

errr

What's it called

The star thing

commutatertot

Moyal product?

Slereah

yeah

Phase space quantization

Emilio Pisanty

12:35

Fun fact: as of January of this year, "(Color online)" is dead. At long last!

David Z

@EmilioPisanty really?

yuggib

@Slereah not really...that is a quantization thing

non-commutative integration/probability is already quantum

Slereah

Then I dunno m8

yuggib

I said that you all should learn it, not that you know it :-P

Emilio Pisanty

@DavidZ Yup. Go have a look.

Maybe start with this one

Slereah

12:38

but I won't

Emilio Pisanty

journals.aps.org/pra/abstract/10.1103/PhysRevA.93.043408

Slereah

You nerd

yuggib

I suggest topics of interest to the community...

:-D

Danu

@EmilioPisanty What is this?

Emilio Pisanty

@Danu So all APS journals used to add "(Color online)" to the caption of every figure which was in colour in the online version but where the author didn't pay for colour prints online.

Which was about half the figures on pretty much every paper

Because, you know, journals.aps.org/authors/color-figures-print

> The charge is US $980 for a single color figure in print and $515 for each additional color figure in the print version of the article.

I found it really annoying

Much better the IOP way

Just say

> (Some figures may appear in colour only in the online journal)

upfront, and you're done

aaaand, finally, APS saw the light and dropped the tagline.

So: "(Color online)" is dead, long live color online!

=P

yuggib

12:49

color figures...never a mathematician's problem (luckily)

btw, when you submit a paper with color figures you really pay the 980$ for each one that has to stay colored on the printed version?

do you have a special part of the fundings/grants/... dedicated to that?

Emilio Pisanty

@yuggib No, you pay $980 for the first one, and then $515 for each one after that

@yuggib That's the theory. I'm not sure who actually does that. Maybe papers from large consortia do it?

yuggib

@EmilioPisanty ok, nevertheless it is common to do that?

Emilio Pisanty

@yuggib No idea

yuggib

I assume you don't do that on your papers...

Emilio Pisanty

Best way is to grab a physical issue of phys rev whatever and skim for colour figures

Slereah

12:52

"On Tuesday 4/3/12, I tweaked the "7 seals"/'beyond Einstein theories' that are revealed on the cover of the 74-page "book/scroll". The very minor revisions that I made was to better express the math equations in 'Seal #6'. I put parenthesis around (God=40/13mt) and moved it closer, so as to clearly make it a part of the 'Conglomeratal Energy eternal Theory'.

I also put parenthesis around '(gods e = 6m ui 10s 9t' and moved it closer, so as to clearly make it a part of the 'Conglomeratal Relationships eternal Theory'. "

Emilio Pisanty

No idea where I'd find one of those around here, to be honest

@yuggib Oh, no, no way. If people with a physical PRA issue (if there are indeed such people anymore) want to see my figures in paper, they can go download it and print it themselves. Latest paper would have cost $8,190 to print in colour, maybe a bit less.

You do have to make sure that your figures are readable on black and white though

mostly for people printing it at home on b/w printers

David Z

@EmilioPisanty a good point, often neglected. Which reminds me, I should check the paper I'm currently reviewing on that point.

I actually didn't realize (color online) was a standard thing. I've seen it, sure, but I read preprints often enough that I didn't see it often.

Emilio Pisanty

@DavidZ Yeah, this is not paid anywhere near enough attention.

Mostly, making sure your figures print reasonably in b/w also makes sure that they're legible to colorblind readers, and those probably make up something like 5% of your audience.

(assuming a male-dominated field and with a fairly broad definition of colorblindness)

@DavidZ Yeah, that's probably true in your field. Mine has something like 40% of papers making it to the arXiv, maybe?

I actually got told off by PRA editorial staff for not including it in my manuscript myself.

David Z

13:10

@EmilioPisanty lol, can't say I ever had that happen.

I guess HEP is rather unique in having essentially 100% arXiv coverage

Emilio Pisanty

@DavidZ To that degree, yeah

Danu

@EmilioPisanty Ah...

Emilio Pisanty

@DavidZ Hmmm. Take that one with a grain of salt btw. I can't find that line now that I look for it.

David Z

Huh, well, not that it matters really. It's good that awareness of online PDFs is presumably high enough that the "(color online)" is no longer needed.

yuggib

@EmilioPisanty yeah, I guessed so

but maybe grants/fundings etc should take that point into account

and be adjusted to allow for color printing of published articles

I assume it is even a worse problem in other more figure rich sciences

Emilio Pisanty

13:21

@yuggib Your budget is your budget, so unless it's earmarked for that specifically, you really need to consider whether your readers are better off with that or with you having better equipment to have better science to write about.

In that front there's similar stuff with open access APCs, e.g. the Wellcome Trust giving funds specifically for making papers open access.

That one is pretty important, but I don't think colour figures really qualifies, at least for a physics paper.

But say you've got some microscopy photographs with, say, structural information encoded in two different dyes? Then yeah, there's a stronger case for paying.

Not sure whether biology publishers tend to charge for colour or not, though.

David Z

Color ink is expensive, so I bet they would. Somebody has to pay for it.

I could see something like the Planck mission paying to have their papers printed in color, too. Astronomy in general has more need for color pictures.

Emilio Pisanty

@DavidZ Do they, though? Do we need colour figures in our print journals? Do we actually read the print version of journals enough for this to really matter? Is printing a bunch of figures in colour really the best use for research-directed tax dollars?

David Z

Well, I mean, assuming the figures are printed in color, somebody has to pay for it. I'm not saying they actually do need to be.

I know I personally don't ever read print versions, but I'm not discounting the possibility that a lot of people elsewhere do.

Slereah

13:44

Hm

If I try to follow peskin or the symmetric lagrangian, I get different results

i wonder if they are identical in the end

Alex

@EmilioPisanty Thanks for the answer, very helpful.

Physics Meta

13:57

0

Q: Posting a picture of my working

I am aware that stack exchange allows me to write beautifully typeset equations in LaTeX. What if, however, I am really lazy. Instead I write my problem out on paper and then take a picture and upload it? Will I get a whole load of moderators moaning at me? I often find that the amount of time ...

discussion

innisfree

14:16

-1

Q: If a being was able to swallow itself, where would it go physically?

if a being was made from a special type of material that allowed it to stretch and was very flexible, if it were to swallow itself, where wold it go. I mean the physical aspects of it since it wont be here anymore. answer anyone?

kinematics universe projectile biophysics displacement

John Rennie

@innisfree words fail me

yuggib

the projectile tag is hilarious

also the universe one to a less extent

innisfree

Indeed. I laughed, then cried, then laughed again :D

John Rennie

@yuggib Projectile vomiting perhaps?

yuggib

@JohnRennie probably

Slereah

14:33

Help

How did I get here

vzn

15:57

@Secret "citizen science" is cool, and a trend, and hope it grows/ builds further, but its kind of a toy-level type concept right now. the "mass unwashed public" cannot contribute much more than gameplaying abilities or contributing distributed computing resources. so if one can do the heavy work to translate ones problem into those two (somewhat narrow) niches (agreed the qm moves game is well done! & apparently well funded!), its possible, otherwise, its still a near fantasy...

John Rennie

16:32

Gosh it's quiet in here without 0celo7 and Barry Carter :-)

David Z

16:44

Yep :-P

Slereah

Well find a topic

I dunno

skill patrol

why is there a dead link on Richard's profile?

Richard, UK

179k 36 1060 1353

star-wars star-trek story-identification harry-potter star-trek-tng movie star-trek-ds9

a whole year seems a bit harsh

John Rennie

If you mean the link to the chat room, that hat room has been deleted. I can still see it, but this presumably goes along with meeting some rep requirement.

skill patrol

@JohnRennie thanx for looking :-)

John Rennie

I don't know the details of what happened in the SFSE, but there was a big issue there with people behaving badly in the chat.

skill patrol

17:00

ya, shog froze the room for a week

John Rennie

It's a bit surprising to see such a high rep user earn themselves such an extended ban, but tempers can flare up and people say things in the heat of the moment. We had a high rep used banned here under similar circumstances, though that was a while ago.

skill patrol

sophie?

John Rennie

Who is Sophie?

skill patrol

she used to be a regular in chat

John Rennie

Anyhow, I wasn't thinking of her. I'm not keen to name names, and in any case it was several years ago so ancient history now.

skill patrol

17:12

as you said, the heat of the moment can be overwhelming for some

while some thrive on trying to light the fuse

DanielSank

18:18

@JohnRennie Good grief the stars in that chat room say it all.

vzn

@DanielSank sounds like something "big" in the works. not many "places" have that kind of severe space constraint on content & would guess its "somewhere elite". are you writing up an experiment or something "else"? =D

you can signal stuff with english language to help it along like "consider the correspondence/ analogy with identical mathematical formalisms" etc

this reminds me of schroedingers eqn... maybe (for half fun, half edu) look at his historical paper for some ideas on how he set up/ introduced that tricky correspondence... although its probably in french right?

de broglie struggled with a similar issue also.

DanielSank

18:44

@vzn Well we'll submit to PRL. Not sure if that counts as "big".

Slereah

Looking at AQFT

I'm thinking that maybe

I should learn algebra first

skill patrol

@DanielSank how many authors?

vzn

@DanielSank ok still topnotch; was guessing science or nature. oh well. maybe next time =D (your lab prob already has some, havent figured it out closely...)

← actually, 2nd thought, maybe PRL has more status/ impact among physicists anyway. science/ nature sometimes have problem of "jack of all trades, master of none..."

Slereah

"This algebra has the non-trivial center $Z = \{ A \in \mathfrak{A}, [A,B] = 0 \forall B \in \mathfrak{A}\}$"

Isn't... isn't that the definition of a center?

Oh apparently it's $\oplus_i \lambda_i 1_{\mathfrak{h}_i}$

Just a linear sum of the identities of the superselection sectors

(heheh, identitties)

vzn

@DanielSank oh & btw, for a physicist who almost likes english more than math, try reading some bohm (ha). wigner to shimony on bohms qm textbook: "too much schmooze"

Slereah

18:53

Can't stop the smooze, @vzn

My Little Pony Song "Nothing Can Stop The Smooze"

►

Obliv

what is $\prod$ called?

Slereah

Iterated product?

bolbteppa

Pi?

Obliv

oh its like a $\sum$ but for products

yeah @slereah

Slereah

yes

Obliv

18:59

that's good to know :P makes things easier

Slereah

Strangely enough there's no equivalent symbol for continued fractions, even though it's a thing

Obliv

hmm.. maybe they ran out of greek symbols/letters

Slereah

math people aren't above making up new symbols

I've seen an author using hearts

it was the cutest paper

Obliv

lmao

AccidentalFourierTransform

@Slereah I've seen people use $K_{i=1}^\infty a_i$ for continued fractions

Slereah

19:09

Oh yeah

Obliv

quick what is the tex command for greater than

detexify messed me up i need to edit a comment D:

Slereah

geq

Oh wait

Just > is fine

Obliv

actually > works

yeah thanks though

John Duffield

@skillpatrol : a whole year isn't as bad as a life sentence.

@JohnRennie : Who? And why?

John Duffield

19:28

Yawn.

Bye.

Slereah

What's the difference between an ideal and a center

Is it just that an ideal is also a subgroup

Slereah

19:46

" the algebra of n×n-Matrizen"

Der Matrizen

Seth Kitchen

As the density increases what happens to the centroid? It increases right?

Bc centroid is directly proportional to density?

Slereah

Can we have a filter on SE

If a question contains "really exist", a warning pops up

vzn

20:03

@JohnDuffield physics.stackexchange.com/help/badges/21/tumbleweed

user54412

@DavidZ Don't forget astro!

user54412

@EmilioPisanty You know, astrophysics has moved to online-only publication. Do you see your field doing that any time soon?

DanielSank

@skillpatrol Why do you ask?

bolbteppa

20:24

@Slereah an ideal is the ring-theoretic analogue of a normal subgroup, but you have group and ring structure at play, while the center of a group is the set of all elements that commute with all elements of the group and from this you can prove that the center is a normal subgroup,

Obliv

20:41

I wonder how the euler function would be programmed @BernardMeurer you should try it m8.

Bernard Meurer

20:57

Who summoned me?

Oh, hey @Obliv

Obliv

helloo

it counts the amount of relatively prime numbers to the input

Bernard Meurer

Do I get some pecan pralines if I succeed?

Obliv

so $\phi(3) = 2$ sure

you would have to be able to distinguish when the inputs are a single number, a number raised to a power, or a prime factorization of the number :D. @BernardMeurer the function is multiplicative when the inputs are relatively prime to each other like $\phi(ab)$ iff $(a,b) = 1$ so for the prime factorization of a number as an input, you just break the function up to a bunch of primes raised to some power.

Bernard Meurer

I have a pretty fast implementation of the sieve of erasthotenes in C++

Hmm

Do you know c++?

Emilio Pisanty

@ChrisWhite I don't really know anyone who reads print versions of journals (but I don't go around asking, either). Or do you mean that journals simply don't print physical copies? I don't really see any of the Phys Revs or the J Phys's doing that, to be honest, and that's where I spend most of my journal time.

Obliv

21:08

@BernardMeurer i have no idea what you just said. i took a semester course at my hs 2 years ago and very quickly forgot anything I learned if that counts :D. i took java for 3ish yrs so I would understand that better

btw, whats the advantage of one language over the other? they're pretty similar, no?

@BernardMeurer I googled it that looks really cool honestly. I don't think it's as complicated for the euler function since it's just relatively prime numbers to the input. not sure tho tbh

Bernard Meurer

@Obliv The sieve you mean? A sieve is a method that is useful for finding primes, I just mentioned it because you said prime factorization and everytime I hear that word I think "Erasthotenes"

Obliv

@BernardMeurer You could reuse that implementation and just automatically count all the primes in between the input and 0. Then you just need to find the other relatively prime numbers by seeing if they have a common factor.

Bernard Meurer

Yep, exactly what I was thinking :)

ACuriousMind

Still talking about boring primes, eh? :P

Obliv

only until I'm done with these exercises. then it's onto the integers modulo whatever that means

vzn

21:19

hi guys some cybersynchronicity, this (yet-unanswered) question popped up recently on Computer Science, similar to some of the number theory youre discussing (prime sieving), based on a programming exercise, maybe someone would like to "take a stab"

4

Q: Sum of divisors summatory function with Erathosthenes' sieve

I ran across the following problem from an online problem bank: there are up to $~10^5~$ queries each of which asks to compute the sum $$\sum_{k = L}^{R} \sigma(k)$$ where $\sigma(k)$ is the sum of divisors of $k$. It is given that $1 \leq L \leq R \leq 5\cdot 10^6$. My solution (described below...

algorithms number-theory

ACuriousMind

"cybersynchronicity" is a very strange word for "coincidence" :P

vzn

@ACuriousMind "synchronicity" comes from jung. one of those non-hard-science (soft) mysticists (@#%&!) ps there is an obscure/ deep connection between primes & QM. still boring? :P

skill patrol

cyber-coincidence?

Obliv

that function gets the sum of all positive divisors to the input not relatively prime numbers :o

ACuriousMind

@vzn "there is an obscure/ deep connection between primes & QM" [citation needed]

vzn

21:25

@ACuriousMind lol like youre gonna read it (sigh)... digging it up...

Obliv

that looks too interesting to turn down I'll give it some thought

ACuriousMind

@vzn I read most of the things you link in support of your...unconventional statements, they just rarely convince me.

vzn

@ACuriousMind awww thx for that :|

...

skill patrol

me too

vzn

in theory salon, Apr 1 at 16:10, by vzn

number theory news/ highlights: prime bias discovery, Diffie-Hellman Turing prize, Zhang-Tao twin primes, Wiles Abel prize, Riemann / Tmachine blog

↑ lol just needed great/ slight excuse to post that here. see [a2] "Dyson/ Montgomery". actually a very old ref... but maybe/ presumably ppl have built on it some... would like newer refs if anyone knows of any...

primes are like the atoms of number theory =D

Bernard Meurer

21:33

@ACuriousMind Primes give me nightmares, as I think I mentioned before here

Obliv

I don't even understand how his first formula retrieves the sum of the divisors of the prime factorization that was inputted.

Bernard Meurer

Which formula?

Obliv

some formulas seriously remind me of paintings. I have to analyze the meanings of the symbols and their relations to each other to get any meaning out of it :(

the one in the question posted by vzn

a)

Joe Stavitsky

Is this ctrlv.in/738353 a correct strategy for this? ctrlv.in/738352

ACuriousMind

@vzn: I'm sorry, but that one may rephrase the Riemann conjecture as the zeros being eigenvalues of a self-adjoint operator, and that they look like the eigenvalues of certain random matrices is not an "obscure/deep connection to quantum physics" since most of quantum physics has nothing to do with random matrices. Not all things that are modelled by the same mathematical theory have a "connection".

Bernard Meurer

21:56

@ACuriousMind You are blinded by your "science"

vzn

@ACuriousMind Dyson/ Montgomery/ others would seem to disagree afaik. admittedly not an expert in this area.

Joe Stavitsky

If I'm given potential difference and charge across a cap and told that inserting the dielectric keeps the same voltage, how can I compute new charge (after dielectric)?

vzn

@Obliv are you going to a university?

ACuriousMind

@vzn I see no evidence of that. Dyson was able to note that the zeta functions zeros appeared to be distributed like eigenvalues of a random matrix, which he was able to see because he had worked with them a lot in the context of physics. This doesn't imply that the zeta function itself actually has something to do with the physical application of random matrices.

And then again, the physical application of random matrices is something far smaller than "quantum physics".

user54412

@EmilioPisanty Yeah, our journals don't even have physical copies anymore. At some point it can't be worth it to maintain the printing facilities and expertise I imagine.

Joe Stavitsky

22:04

Or can I use V=Fd/q

Obliv

@vzn I wouldn't consider the school I'm going to currently a university. I plan on transferring to a real university next year, though. How about you?

vzn

@Obliv work in industry. graduated BS software engr decades ago

@ACuriousMind so let me guess, you would argue with Sautoys assertion as follows seedmagazine.com/content/article/prime_numbers_get_hitched

> It is striking that Dyson should have written about scientific ships passing in the night. Shortly after he published the piece, he was responsible for an abrupt collision between physics and mathematics that produced one of the most remarkable scientific ideas of the last half century: that quantum physics and prime numbers are inextricably linked.

ACuriousMind

Yeah, that's a ridiculous overstatement.

vzn

ah, ahem, must admit think others have criticized sautoy. he writes popsci book(s). horrors o_O

so guess magic doesnt exist in the universe, after all :(

kevin Tah N.

back in the day I hung out at a school in Northern California(I have done this at 3 schools in this region) anywho, I wanted someone to teach me CFT, and they said I needed to know GR first. I get where they are coming from, but they should have just told me about the Killing differential equation, and then said . . . . . g \rightarrow \Omega g and then . . . . . 2 dimensions infinitely awesomely symmetric. . . .

Any who, what's up with cross ratios, and who came up with that stuff

I used to think it was voodoo

trilolil

22:15

Hello guys

kevin Tah N.

hey dude

trilolil

I permit myself to ask my question here as it is interdisciplinary

kevin Tah N.

lol

trilolil

and there is nobody in the mathematic rooms

Obliv

what is CFT @kevinTahN. ? Just curious since I know nothing about anything ;p

trilolil

22:16

I have some difficult equations (imgur.com/z0QQXfQ)

which I need to combine in order to obtain this:

imgur.com/Ttofv2H

what would be the best way to start and to verify whether it is even possible?

@kevinTahN. any idea?

:(

vzn

@ACuriousMind hmm, surfing around... so some pair of oxford profs (Keating/ Snaith) are not much good enough for you either? keeping those stds astronomically high as usual! bristol.ac.uk/maths/research/highlights/riemann-hypothesis

ACuriousMind

@vzn You have to read what technical statements they actually make! You keep citing these press releases and articles which are purposefully more grandiose-sounding

vzn

@ACuriousMind the press release (horrors!) was written probably with the influence of the profs themselves. the PR is excited, but factual at same time.

ACuriousMind

@vzn For instance, this is the actual Keating/Snaith paper. The phrase "quantum physics" doesn't appear at all in this paper, and the only time "quantum" appears is in reference to a conjecture that in the semiclassical limit all generic chaotic systems have the same distribution of eigenvalues as these zeros.

kevin Tah N.

@Obliv It is a type of (Quantum)field theory which posses a special type of symmetry. Typically people would say angles are preserved, which is true. I was told this, but it probably does not say much.

vzn

22:23

this reminds me of a conversation with a hollywood dude c~2000 complaining about a siggraph simulation, a few yrs before similar technology went on to make billions $$$ for pixar etc...

Joe Stavitsky

ctrlv.in/738363 could someone suggest a strategy please?

kevin Tah N.

The trick is to learn this by first thinking of where Killing vectors come from in GR, then the meaning of Conformal killing vectors, then invoking Noether theorem, and computing the Lie algebra. Most texts just dump virasoro algebras without properly motivating them, . . . may be learning Witt algebra and how they arise naturally is a good idea.

Anyways I am no expert, but I think Conformal Field theory is just a consequence of relaxing the "Killing condition" in GR. when you do this you arrive at two possible transformations.

ACuriousMind

Nowhere do they speak about something so general as a connection to "quantum physics", or suggest that the zeta function itself might be related to physical dynamics.

That's because they are competent people, and make specific useful claims instead of sweeping generalizations.

kevin Tah N.

@Obliv I wrote a bit to answer the question, but I am far from being an authority on any of this, all I have done is attempt to articulate my tiny understanding of what I think CFT is all about

vzn

@ACuriousMind not an expert on this stuff, but think you are mischaracterizing it to some degree.

kevin Tah N.

22:27

@trilolil hey dude, I could not find what you were asking about. Can you try to articulate the question in the chat. I will look at it but most importantly there are more competent people on here who would see it too, and are best prepared to help

ACuriousMind

@kevinTahN. The problem is that at the usual level of physicist's rigor it's always going to be a bit confusing where the hell that "central charge" in the passage from the Witt to the Virasoro algebra comes from :P

kevin Tah N.

Hehehe, that's true :D

vzn

29

Q: Riemann Zeta Function connection to Quantum Mechanics.

I feel like this question is probably wrong for MO, (too low level, perhaps unclear) but my curiosity has got the better of me: I hear that the Riemann Zeta Function and its zeros have applications to quantum mechanics, as well as other fields. I do not understand these connections, and because...

nt.number-theory

Hilbert–Pólya conjecture

In mathematics, the Hilbert–Pólya conjecture is a possible approach to the Riemann hypothesis, by means of spectral theory. == History == In a letter to Andrew Odlyzko, dated January 3, 1982, George Pólya said that while he was in Göttingen around 1912 to 1914 he was asked by Edmund Landau for a physical reason that the Riemann hypothesis should be true, and suggested that this would be the case if the imaginary parts t of the zeros of the Riemann zeta function corresponded to eigenvalues of an unbounded self-adjoint operator. The earliest published statement of the conjecture seems to b...

ACuriousMind

@vzn: Note: I am not saying there is nothing in quantum mechanics that is connected to something about the zeta function. What I'm saying is that statements like "quantum physics and prime numbers are inextricably linked" are far too broad. There is a specific subfield of quantum mechanics in which the same patterns as in the zeros of the zeta function show up. But that's it.

vzn

@ACuriousMind think this is a work in progress/ crosscutting research program that involves topnotch scientists building on it (with quite different bkgs, ie math/ physics, hence some cultural gap), that it may develop to more in the future, and agree parts of it are merely sketchy/ coincidental at this point.

eg more here ias.edu/about/publications/ias-letter/articles/2013-spring/…

nice survey here arxiv.org/abs/1101.3116 Schumayer / Hutchinson

ACuriousMind

22:39

@vzn Now that's a nice article! It's specific about where the connections lie, and which quantum systems actually show the relevant behaviour.

kevin Tah N.

@trilolil actually you can send me the equations, I could probably give them to a little program I wrote to see if it solves them, otherwise I could try to solve them sometime tonight. As long as they are some form of applied functional analysis I should be able to say something about them :P, no promises though

vzn

@ACuriousMind lol it was written by physicists... ok then!

ACuriousMind

@vzn Hmmm? I mean the one from ias, which appears to have been written by "just" a journalist :P

vzn

this turned up too. looks like a term paper maybe by grad student...? guava.physics.uiuc.edu/~nigel/courses/563/Essays_2008/PDF/… / Lyon

Obliv

if a liquid mass starts out in the shape of a sphere and experiences a force acting on it in one direction and a force acting on it in the opposite direction, would the shape change? I imagine yes..

ACuriousMind

22:43

@vzn Arrrrgh, it's in Word, my eyes!

2

Obliv

If it were only 1 force in one direction I feel like the mass would stretch. Not sure though. For the example above though I feel like it would oscillate or something crazy.

ACuriousMind

Seriously, these inserted formulae look horrible :P

vzn

:: evil laugh, bwaHAHAHA! ::

ACuriousMind

@Obliv How are the forces acting on the "liquid"? Typically, you can't have forces acting on a "liquid" because it just gives way to whatever is exerting the force.

Obliv

It's gravity for one, the other would be drag force which would act perpendicular to the surface.

ACuriousMind

22:46

@Obliv So...you're trying to tell me you're wondering what the shape of a raindrop is? :P

Obliv

yea :D

drag force is basically an enormous amount of collisions/momentum impartation so I imagine some weird things would happen to the liquid

brb

Emilio Pisanty

@ChrisWhite That's crazy!

But also, I guess, why not

ACuriousMind

@FenderLesPaul: Here's an Academia question for you ;)

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