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11:07 PM
"In this case, the spinor bundle $S_M$ is associated with the $L_s$-lift $P_h$ of $L^h X$ : $$S_M = S_h = (P_h \times V) / L_s$$"
Blublublu
Enough bundles for tonight
 
so...the WEC is enough for what I want
 
It usually is
 
quoting HE, Sanchez
some good physics here boi
$$\int_{\mathscr H(t)\cap\mathscr U}T^{ab}t_{;a}\, d\sigma_b\le -\int_{\partial_1\mathscr U}T^{ab}t_{;a}\, d\sigma_b+P\int^t\int_{\mathscr H(t')\cap\mathscr U}T^{ab}t_{;a}\, d\sigma_b \, dt'$$
@Slereah hmm, how does one get the integrals closer
 
closer to what
 
to the other integral
$$\int^t\int_{\mathscr H(t')\cap\mathscr U}$$
 
11:18 PM
No idea
Not sure what most of those symbols are
 
I literally mean the spacing of the integrals looks off
 
Oh
There's a backspace symbol IIRC
$$\int^t\!\!\int_{\mathscr H(t')\cap\mathscr U}$$
Better?
$$\int^t\!\!\!\!\int_{\mathscr H(t')\cap\mathscr U}$$
 
@Slereah ah right the exclamation mark
that's how one does dirac notation, right?
 
it is one possible way, yes
 
ugh how is surface measure defined in GR
 
11:34 PM
@Slereah hmm, do you know if the "usual" induced metric $g_{\mu\nu}+n_\mu n_\nu$ is just the pullback metric?
 
Do you mean with $g$ the Riemannian metric?
and $n$ a timelike vector
 
$g$ is the metric of spacetime and $n$ is the normal to the spacelike hypersurface
 
Oh
I do not know
 
hmm, this is a bit of an abuse of notation (what else is new)
@Slereah Consider the embedding $i:\Sigma\to M$
If $h=g+n\otimes n$, then $h|T\Sigma=i^*g$
 
I'd believe it
Just gotta prove that $$g(v,w) + n \otimes n (v, w) - g(df(v), df(w)) = 0$$
What's the formula for $n$, is it just $df$
You got like $n \otimes n(v, w) = n(v) \cdot n(w)$ right?
Wait no, the second metric is the wrong space
Or is it
It's too late for diff geom
 

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