$$T=\frac{16k_1^2k_2^2}{(k_1-k_2)^4+(k_1+k_2)^4-2(k_1-k_2)^2(k_1+k_2)^2\cos(2k_2‌​l)}$$

please simplify this :/

Hm, what would be the hyperreal version of that Fock space

I'm guessing the single particle Hilbert space would be $^*\mathcal{L}^2({}^*X^+, {}^*d\lambda)$

By the transfer theorem

I also have to define a hyperreal spacetime I guess

Blah

@Slereah no one knows what you're talking about

I also never know what you're talking about

yet I am not bitching

@Slereah Basically, yes. You take the single-particle space $L^2(X)$ where $X$ is the positive mass-shell (i.e. all orthochronous four-momenta whose square is the mass of the field) and the measure is the standard Lorentz invariant measure, build the Fock space out of it and define the quantum field as the Fourier transform of the creation/annihilation operators.

Seems a bit backward, but I have too much on my plate to complain

By the properties of the Fourier transform and because the functions are on-shell, it then turns out that this field is a (distributional) solution to KG

again, the anti-0celo7 star squad

what a bunch of trolls

I guess I need to look up how Fourier transforms work in $^*R$

Well, I know nothing about your hyperreal situation, I just told you how you would construct a free Wightman field that fulfills KG

That sounds fine yeah

I'm guessing that by transfer Fourier transforms are pretty simple

But then you have

INFINITE FREQUENCY MODES

D:

Dun dun duuun

holy god

I think I'm simplifying correctly

I don't think we are Duckett

Who the heck would buy physics.SE in bookform?!

If I'm in it can I sue

Did it.

page 6

I finally computed it

I dunno

I don't talk QFT that much

Eh not often

and not in much details

@ACuriousMind Are you proud?

And in one case I answered my own question

@Slereah You can't, SE content is free to be used if proper attribution is given

Where's my moneyyyy

I'm not in the GR section

Probably not in it then

Motl is in it, tho

amazon.com/General-Relativity-Questions-George-Duckett/dp/…

On the other hand

What's in this

Don't seem to be in it either

@Slereah We can probably sue if the book is not itself licensed under cc-by-sa, though

What does the copyright notice say?

@bloo lol

lol

@ACuriousMind I mean, you should be proud. I solved a 4x4 system by hand, then did about 3 pages of algebra to simplify it.

It doesn't seem to have my best rated answer ever about spacetime topology

I'm almost at high school level algebra level :D

needed response to my working on this question please click physics.stackexchange.com/questions/285292/…

wonder what $\sinh^2$ is

@bloo he pirated it

click on the "look inside" button on amazon

@Surdz This site is not for instant help, and in particular we don't check-your-work or do your homework for you. Why do you "need" a response?

though not all pages are in it

Now I feel like I have to buy this book to check if I'm in it

He's a smart man

@ACuriousMind please i already do it i just need a comment if I am on the right track.

that wouldn't be right

I wonder if my Lorentz stokes is in there

I'd better pirate it instead

it's probably the only place it's ever been published properly

@bloo : See this meta post.

the chapter on causality is missing from amazon

Which is unfortunate

It's the most likely place for me to be

YES

I solved the problem

Ok, next one!

@ACuriousMind In what cases do I smooth the derivatives of the wave function?

Just when the potential is finite, right?

Like in the infinite well, the derivatives will be discontinuous at the edge of the well

Yes, I think the potential needs to be bounded/a proper function to get differentiable solutions

I seem to remember a Qmechanic post about that somewhere, but I can't immediately locate it

Howdy

oh my god

I have to solve the harmonic oscillator in the position basis

HOW

why is this homework so hard

Hermite polynomials

@Slereah well yeah

hmm

I just need the odd ones

I mean it's a polynomial

You can just write the Taylor series I guess

And solve it from there

aha

@ACuriousMind Eh, I'd argue things like cosmology, which try to explain the Big Bang or the past in general, attempt to answer why the Universe ended up the way it did

What's up with this? physics.stackexchange.com/a/284672/40681

@0celo7 I wanted to thank you again for the book advice earlier, I've only had time to read the introduction, but I really like the structure it is laying out and I am really excited to read through it (slowly as I unfortunately do not have that much time :< )

I've heard the answer many times but only now actually started to think about it.

@Sanya It is a very good book

Not good for learning the basics from, but for "crazy" stuff it's very good

@0celo7 those books, in the end, are more valuable than basics books that leave you with a lot of unresolved questions ...

which book?

Gourgoulhon is a good book

On the other hand

Obviously fake name

haha

hahahhaa

I have to compute expectation values of fucking Hermite polynomials

shoot me

They can call themselves Slartibartfaß if they want as long as the books they write are good

Sounds like a good German name to me

@0celo7 can you not use the algebraic relations? :< HO is so much easier without a basis ...

@0celo7 If I remembered the name correctly, it's from an English book ...

@Sanya I have to compute $\langle x^2\rangle$ but the state is not really SHO

hmm damn

it's a mutilated $n=1$ mode

identically 0 for $x<0$

so I have to compute $\int_0^\infty |\psi^2|x^2$

I bet Shankar has the first few ones written down

what's the difference between a foliation and a fibre bundle?