Moore General Relativity | Workbook Solutions

After some calculations, we find that the geodesic equation becomes

$$\frac{d^2t}{d\lambda^2} = 0, \quad \frac{d^2x^i}{d\lambda^2} = 0$$

The geodesic equation is given by

$$\frac{d^2r}{d\lambda^2} = -\frac{GM}{r^2} + \frac{L^2}{r^3}$$ moore general relativity workbook solutions

The equation of motion for a radial geodesic can be derived from the geodesic equation. After some algebra, we find

where $\lambda$ is a parameter along the geodesic, and $\Gamma^\mu_{\alpha\beta}$ are the Christoffel symbols.

The gravitational time dilation factor is given by After some calculations, we find that the geodesic

Consider the Schwarzschild metric

Derive the geodesic equation for this metric.

Using the conservation of energy, we can simplify this equation to Using the conservation of energy, we can simplify

$$\Gamma^0_{00} = 0, \quad \Gamma^i_{00} = 0, \quad \Gamma^i_{jk} = \eta^{im} \partial_m g_{jk}$$

$$\frac{d^2x^\mu}{d\lambda^2} + \Gamma^\mu_{\alpha\beta} \frac{dx^\alpha}{d\lambda} \frac{dx^\beta}{d\lambda} = 0$$

Derive the equation of motion for a radial geodesic.

where $L$ is the conserved angular momentum.

$$\frac{t_{\text{proper}}}{t_{\text{coordinate}}} = \sqrt{1 - \frac{2GM}{r}}$$