Solutions to this set of ODEs hold for all affine transformations of the parameter with respect to which total derivatives are taken. For 10 points each:
[10h] Name these equations that are satisfied when a total covariant derivative of the tangent vector equals a total derivative of the tangent vector plus Christoffel symbols times the tangent vector times a total derivative of position.
ANSWER: geodesic equations
[10e] A common choice of parameter of differentiation in the geodesic equations is this quantity, the time measured by a clock as it follows a timelike geodesic.
ANSWER: proper time
[10m] Two answers required. For negligible velocity, the geodesic equations with respect to proper time reduce such that the covariant indices of the Christoffel symbols are these two values. The component of the stress-energy tensor with these indices is the energy density.
ANSWER: zero AND zero
<Geoffrey Wu, Physics>