- #1

- 663

- 20

## Main Question or Discussion Point

In the formula : ##\frac{d^2 x^\mu}{d\tau^2}=-\Gamma^\mu_{\alpha\beta}\frac{dx^\alpha}{d\tau}\frac{dx^\beta}{d\tau}##

How is the ##x^\mu## understood : a 4-vector or the ##\mu##-st component simply ?

If it is a vector, how to write it in spherical coordinate with extra time dimension ?

Btw: why does one not solve EFE in 3 space timensions and then solve the geodesic equation with ##\tau\rightarrow t## ?

How is the ##x^\mu## understood : a 4-vector or the ##\mu##-st component simply ?

If it is a vector, how to write it in spherical coordinate with extra time dimension ?

Btw: why does one not solve EFE in 3 space timensions and then solve the geodesic equation with ##\tau\rightarrow t## ?