Dynamics of extended bodies in general relativity center-of-mass description and quasirigidity

@article{Ehlers1977DynamicsOE,
  title={Dynamics of extended bodies in general relativity center-of-mass description and quasirigidity},
  author={J{\"u}rgen Ehlers and Ekkart Rudolph},
  journal={General Relativity and Gravitation},
  year={1977},
  volume={8},
  pages={197-217}
}
Dixon's approach to describe the dynamics of extended bodies in metric theories of gravity is elaborated. The exact, general relation between the center-of-mass 4-velocity and the 4-momentum is derived. Quasirigid bodies are defined, and their equations of motion are shown to be determinate for a given metric. Multipole approximations are considered, and the physical meaning of quasirigidity is investigated by establishing an approximate connection with continuum mechanics. 

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