paweld
Dec30-09, 04:19 PM
What is the interpretation of stress energy-tensor in general relativity.
According to General Relativity by Wald T^{\mu\nu} u_\mu u_\nu
is energy density (chapter 4.2) where u_\mu is observer 4-veliocity.
But for isolated particle T^{\mu\nu} = \gamma m V_\mu V_\nu
(http://en.wikipedia.org/wiki/Stress_energy_tensor#Isolated_particle) in particle reference frame
we obtain density of energy: m / \gamma and not m
(because V_\mu^2=1/\gamma^2 - it's not 4-veliocity but simpliy veliocity).
According to General Relativity by Wald T^{\mu\nu} u_\mu u_\nu
is energy density (chapter 4.2) where u_\mu is observer 4-veliocity.
But for isolated particle T^{\mu\nu} = \gamma m V_\mu V_\nu
(http://en.wikipedia.org/wiki/Stress_energy_tensor#Isolated_particle) in particle reference frame
we obtain density of energy: m / \gamma and not m
(because V_\mu^2=1/\gamma^2 - it's not 4-veliocity but simpliy veliocity).