- #1
ArthurB
- 17
- 0
I have some problems using this definition, maybe because it's not valid in every coordinate system:
[tex]
T^{\mu\nu} = (\epsilon + p) \frac{dx^{\mu}}{ds} \frac{dx^{\nu}}{ds} -p g^{\mu\nu}
[/tex]
since in cylindrical coordinates
[tex]
x^0 =t \qquad x^1 =\rho \qquad x^2 = \phi \qquad x^3 =z
[/tex]
using weyl metric
[tex]
g_{00}= e^{2u} \qquad g_{11}=-e^{2v-2u} \qquad g_{22}=-\rho^2 e^{-2u} \qquad g_{33}=-e^{2v-2u} \qquad u=u(\rho,z) \qquad v=v(\rho,z)
[/tex]
I obtain
[tex]
T_{11}=T_{33}
[/tex]
but from the definition of the einstein tensor I obtain
[tex]
G_{11}=-G_{33}
[/tex]
but einstein equation says
[tex]
G_{\mu\nu}=8\pi k T_{\mu\nu}
[/tex]
which in this case then implies
[tex]
T_{11}=-T_{33}
[/tex]
in contraddiction with the result obtained from the first formula.
can anyone explain?
[tex]
T^{\mu\nu} = (\epsilon + p) \frac{dx^{\mu}}{ds} \frac{dx^{\nu}}{ds} -p g^{\mu\nu}
[/tex]
since in cylindrical coordinates
[tex]
x^0 =t \qquad x^1 =\rho \qquad x^2 = \phi \qquad x^3 =z
[/tex]
using weyl metric
[tex]
g_{00}= e^{2u} \qquad g_{11}=-e^{2v-2u} \qquad g_{22}=-\rho^2 e^{-2u} \qquad g_{33}=-e^{2v-2u} \qquad u=u(\rho,z) \qquad v=v(\rho,z)
[/tex]
I obtain
[tex]
T_{11}=T_{33}
[/tex]
but from the definition of the einstein tensor I obtain
[tex]
G_{11}=-G_{33}
[/tex]
but einstein equation says
[tex]
G_{\mu\nu}=8\pi k T_{\mu\nu}
[/tex]
which in this case then implies
[tex]
T_{11}=-T_{33}
[/tex]
in contraddiction with the result obtained from the first formula.
can anyone explain?
Last edited: