What Are the Conditions on Christoffel Symbols for Given Geodesics?

unscientific
Messages
1,728
Reaction score
13

Homework Statement



Using the geodesic equation, find the conditions on christoffel symbols for ##x^\mu(\tau)## geodesics where ##x^0 = c\tau, x^i = constant##.
Show the metric is of the form ##ds^2 = -c^2 d\tau^2 + g_{ij}dx^i dx^j##.

Homework Equations

The Attempt at a Solution



The geodesic equation is
\frac{d^2x^\mu}{d\tau^2} + \Gamma^\mu_{\alpha \beta} \frac{dx^\alpha}{d\tau} \frac{dx^\beta}{d\tau} = 0
\Gamma^\mu_{\alpha \beta} = \frac{1}{2} g^{\mu \gamma} \left( \partial_\alpha g_{\gamma \beta} + \partial_\beta g_{\alpha \gamma} - \partial_\gamma g_{\alpha \beta} \right)

For ##x^0 = c\tau##, we have that ##\Gamma^0_{00} = 0##. This means that ##\partial_0 g_{\gamma 0} = \frac{1}{2} \partial_\gamma g_{00}##. How does this help??
 
Physics news on Phys.org
bumpp
 
bumpp
 
bumpp
 
Thread 'Need help understanding this figure on energy levels'
This figure is from "Introduction to Quantum Mechanics" by Griffiths (3rd edition). It is available to download. It is from page 142. I am hoping the usual people on this site will give me a hand understanding what is going on in the figure. After the equation (4.50) it says "It is customary to introduce the principal quantum number, ##n##, which simply orders the allowed energies, starting with 1 for the ground state. (see the figure)" I still don't understand the figure :( Here is...
Thread 'Understanding how to "tack on" the time wiggle factor'
The last problem I posted on QM made it into advanced homework help, that is why I am putting it here. I am sorry for any hassle imposed on the moderators by myself. Part (a) is quite easy. We get $$\sigma_1 = 2\lambda, \mathbf{v}_1 = \begin{pmatrix} 0 \\ 0 \\ 1 \end{pmatrix} \sigma_2 = \lambda, \mathbf{v}_2 = \begin{pmatrix} 1/\sqrt{2} \\ 1/\sqrt{2} \\ 0 \end{pmatrix} \sigma_3 = -\lambda, \mathbf{v}_3 = \begin{pmatrix} 1/\sqrt{2} \\ -1/\sqrt{2} \\ 0 \end{pmatrix} $$ There are two ways...
Back
Top