[math]\rho^{i} =T^{0 i}/v^{i}[/math]? Not sure I understand what that means. The indices don't balance and I don't understand the meaning of division here.

 

Anyway, am not going to be about for at lest a week. Sorry for the lack of the near future responses.

[math]\rho^{i} =T^{0 i}/v^{i}[/math]? Not sure I understand what that means. The indices don't balance and I don't understand the meaning of division here.

T⁰ⁱ is the ith component of momentum density, vⁱ is the ithe component of 3 velocity and [math]\rho^{i} =T^{0 i}/v^{i}[/math] is the ratio of the two.

Anyway, am not going to be about for at lest a week. Sorry for the lack of the near future responses.

Have fun!

 

In the mean time I have to look into this more. It seems that I made an error above. The mass density as given by both Tolman and Rindler is

 

[math]\rho = \gamma^2 (u) (\rho_0 + u^2t_0^{11}/c^4)[/math]

 

which is not the ratio of momentum to speed as I believed. However the term proper mass densit does seem to have a unique meaning and thus is well defined.

 

Pete