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(Please excuse my English)

In Newtonian mechanics and gravity, these are obvious.

  • Momentum is conserved in gravity action.
  • Momentum is conserved in real force action.
  • Momentum is not conserved in fictitious force action.
  • So gravity is a real force.

I do not know much about general relativity(=GR). However, I know these.

  • In GR, gravity is described as moving in spacetime curvature.
  • So gravity is a fictitious force in GR.

Am I right?

If gravity is a fictitious force, momentum is not conserved in gravity of GR?

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  • $\begingroup$ Possible duplicates: physics.stackexchange.com/q/62939/2451 , physics.stackexchange.com/q/360930/2451 and links therein. $\endgroup$
    – Qmechanic
    Jun 8 '18 at 17:44
  • $\begingroup$ @Qmechanic : Thank you. I will read the questions. $\endgroup$
    – pdh0710
    Jun 8 '18 at 18:24
  • $\begingroup$ @safesphere : I cannot understand which part of the linked question is related to my question. Could you explain more detail? $\endgroup$
    – pdh0710
    Jun 8 '18 at 18:27
  • $\begingroup$ @Qmechanic : I read the questions and answers you linked(=the posts). What I learned from the posts are : "Force, mass, momentum, energy, etc., are notoriously subtle in GR for a generic spacetime." "Momentum conservation can be defined under limited conditions in GR." Am I rightly understood? $\endgroup$
    – pdh0710
    Jun 9 '18 at 12:24
  • $\begingroup$ @safesphere : You said "Momentum is conserved with a fictitious force in the frame of reference where this force exists." What is the "this force"? $\endgroup$
    – pdh0710
    Jun 9 '18 at 12:26