Yeah, I think I'm just trying to oversimplify the equation. It works fine with the sum there, but I'm always suspicious when working with infinite sums that I'll do something subtly wrong, and it feels like there should be some elegant continuous function there.
If ##a = 0## it gives ##T = t##, which is the desired result, since it should look just like flat Minkowski coordinates in that case.
I'm just hoping for a way of writing it which is clearly ##T = t## when ##a = 0## and ##T = \frac{sinh(at)}{a}## otherwise, without the gap in the domain of the...
Rindler coordinates are nice, but they fall apart when a=0, where ##T=\frac{sinh(at)}{a}=\frac{0}{0}##. Is there a good way to fix that?
Intuitively I'd want to do out the taylor expansion, divide by a, then collapse it back to... something...
$$T=\frac {\sinh(at)} {a}=\frac{ \sum_{n=0}^\infty...
Sorry, I'm prone to speaking imprecisely, and I'm still learning the correct terminology in GR. I think I'm looking for the metric perturbation caused by the existence of a single photon. Ideally I'd like christoffel symbols, or a line element, or something equivalent which describes the gravity...