# Fermi Normal Coordinates

1. Oct 1, 2012

### PLuz

Hi everyone,

Defined the Fermi Normal Coordinates (which can be seen for example http://relativity.livingreviews.org/open?pubNo=lrr-2011-7&amp;page=articlese10.html" [Broken]) is there any heuristic argument to explain why the area element is something proportional to the element of solid angle? I was trying to find a way to avoid the need to compute explicitly the area element in order prove for the first and third results of Eq.17.26 of that reference...

Any ideas?

Thank you

Last edited by a moderator: May 6, 2017
2. Oct 3, 2012

### clamtrox

Surely it's because the 2 (or n? doesn't seem to matter)-sphere you're integrating over is a symmetric domain, and the integrand is always odd in at least one of the coordinates, so the integral has to vanish. The second result is the non-trivial one.