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8:02 PM
I'm proud of you!
 
It did require asking DS & a friend for help
my friend walked me through the phone and, most importantly, made me give up on trying to flip the egg like a chef with just one hand on the pan
 
...what exactly about "crack open egg, put into ban, stop before it's burnt" did require two people to assist you? :D
 
lol, just don't try flipping stuff like that
 
@Slereah I hath not...
the free vacuum in the wavefunctional rep is just $1$
(seen as a constant functional, square integrable wrt the gaussian measure)
 
8:10 PM
@ACuriousMind Why is there no [magic] tag for questions?
 
@yuggib Well 1 up to a phase, yes
 
the ladder operators I don't know exactly...probably they are derived by linear combination from the fields
@Slereah no no, just one
 
Why no phase?
Aren't all wavefunctions defined up to a phase
 
@BernardMeurer [There is].
 
8:12 PM
So the normalization is just $\int d\mu(\varphi) = 1$, right?
 
not really...they are the square integrable functions wrt the gaussian measure
 
With $\mu$ the Gaussian measure
 
exactly
 
Hm
So $\langle 0 | \varphi | 0 \rangle = \int \varphi d\mu = 0$ makes enough sense, I guess?
It's the mean of the gaussian measure
 
yes, that's it
 
8:15 PM
I have this Feeling that maybe $a^\dagger_k \approx \varphi_k$, with $\varphi_k$ the one particle wavefunction
And I guess maybe $a_k = \frac{\delta}{\delta \varphi_k}$, if that makes sense?
 
@BernardMeurer I have nothing to edit there
 
@ACuriousMind I'm glad :)
 
@Slereah not exactly
the field is the multiplication by the variable, and the momentum is the derivation plus the variable
 
Yes, but isn't that what we are supposed to get
 
yes, more or less
 
8:18 PM
$\hat a^\dagger_k | 0 \rangle = a^\dagger_k 1 = \varphi_k(x)$
Although...
I suppose the two operators wouldn't be complex conjugates then
Hm
 
the cre ann ops can be derived by the. field and momentum by linearity
 
yeah
Something like $$a_k(x) = \frac{1}{\sqrt{(2\pi)^n 2 \omega_k}} \int d^n x e^{ikx} (\omega_k \varphi(x) + \frac{\delta}{\delta \varphi(x)} - \varphi(x))$$
Not quite sure how to simplify it, though
 
well, something like that
but maybe there is a more explicit form somewhere in the literature
 
probably
I tried looking up Rovelli but then again it has $\pi = \frac{\delta}{\delta \varphi}$
Might not be too exact
Also is $\pi = -i(\frac{\delta}{\delta \varphi} - \varphi)$?
Seems a bit weird, unit-wise
 
yeah it's something like that
 
8:29 PM
It ends up giving a term like $\varphi (\omega_k - 1)$ for $a$
 
@BernardMeurer Uh, do you not know what he looks like?
@ACuriousMind ...what
image of what
 
Image of the point
 
under?
 
@0celo7 ACM you mean?
 
yes
 
8:35 PM
@0celo7 I know how he looks. Even tried adding him on facebook but he said he hated me and wished I was dead :(
 
savage
 
That may or may not be an accurate representation of events
 
@ACuriousMind I still don't get what "fiber preserving" means
 
@ACuriousMind We'll see about that in court
 
I'm bad at algebra
 
8:39 PM
I'm the victim, you can't disagree with me. Stop victim shaming
 
@ACuriousMind Argh, what the heck does fiber preserving mean :/
 
I don't know what your problem is
 
Everyone says it maps fibers into fibers or something
Which fiber gets mapped into which fiber?
 
$f(E_x)\subset E'_{\pi(f(x))} = E'_x$.
 
Aha, that's my issue
What is $f(x)$
what the heck
what is $\pi(f(x))$
What is $x$?
 
8:46 PM
A point in the base.
 
$f$ is defined on $E$, not the base.
Assuming $f:E_1\to E_2$
 
Okay, yeah
Fiber preserving just means $f(E_x)\subset E'_x$.
 
???
What if the bases are different
And what is $E'_x$
 
Then it means that the diagram on that Wiki pages commutes
 
8:48 PM
@0celo7 I'm calling the bundles E and E' because I don't want to type double indices
 
@ACuriousMind oh
@ACuriousMind which one
 
@0celo7 ...there is only one that applies for the case where the bases are different.
The fiber-preserving aspect in that case is that if one point of $E_x$ lands in $E'_y$, then already $f(E_x)\subset E'_y$.
 
How do you define the map between the bases
 
You don't
 
Wiki's $f$ IIRC
 
8:51 PM
It is a requirement that it exists.
But you can recover it from $f(E_x)\subset E'_y$ in an obvious way.
 
@ACuriousMind ...
how
I'm not doing too hot today
 
No, I'm not writing that down
 
9:09 PM
@ACuriousMind do you just project the mapped fiber onto the second base
 
@ACuriousMind I would ask why you didn't write that but you'd get annoyed
 
9:36 PM
Hello, good evening. Can someone please help me with mathematical explanation of a physical concept?
 
 
1 hour later…
10:48 PM
@ACuriousMind what is the tensor product of matrices?
 

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