- #1

WannabeNewton

Science Advisor

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Hey guys. So in the einstein gauge the linear field equations can reduce to the wave equations:

[tex]\partial^{2} _{t}h_{ab} [/tex] - [tex]\nabla^{2}[/tex][tex]h_{ab} [/tex] = 0 where here [tex]h_{ab} [/tex] is the symmetric tensor containing the deviation of the gravitational field from minkowski space for the weak field. How can one tell from this that gravitational waves propagate at light speed? I guessed and thought it was because the laplacian is usually followed by a c[tex]^{2}[/tex] for the speed of the wave and in this case c[tex]^{2}[/tex] is 1 and since this is in geometric units I assumed that this was the indicator that gravitational waves travel at light speed. Of course I am probably completely off so if you guys could tell me why they do travel at said speed I would really appreciate it. Thanks.

[tex]\partial^{2} _{t}h_{ab} [/tex] - [tex]\nabla^{2}[/tex][tex]h_{ab} [/tex] = 0 where here [tex]h_{ab} [/tex] is the symmetric tensor containing the deviation of the gravitational field from minkowski space for the weak field. How can one tell from this that gravitational waves propagate at light speed? I guessed and thought it was because the laplacian is usually followed by a c[tex]^{2}[/tex] for the speed of the wave and in this case c[tex]^{2}[/tex] is 1 and since this is in geometric units I assumed that this was the indicator that gravitational waves travel at light speed. Of course I am probably completely off so if you guys could tell me why they do travel at said speed I would really appreciate it. Thanks.

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