Friday, June 8, 2018

The Parameterized Post-Newtonian Framework

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Recorded: 11/12/2017 Released: 6/8/2018

Randy and Jim discuss the Parameterized Post-Newtonian Framework, a generalized way to compare metric theories of gravity to experiment in a standardized way. In this episode we discuss several theories of gravity and how they hold up under the light of experimental data.

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A Guide to the Parameters


  • γ (gamma) - Coupling of matter to curvature, GR = 1 , Newton = 0
  • β (beta) - Linearity of superposition, GR = 1 - Superposition linear
  • ξ (xi) - Preferred location effects, GR = 0 - Spatially homogeneous
  • α1 (alpha) - Preferred frame effects, GR = 0 - Lorentz invariant
  • α2 (alpha) - Preferred frame effects, GR = 0 - Lorentz invariant
  • α3 (alpha) - Preferred frame effects, GR = 0 - Lorentz invariant
  • ζ1 (zeta) - Momentum changes, GR = 0 - Momentum conserved
  • ζ2 (zeta) - Momentum changes, GR = 0 - Momentum conserved
  • ζ3 (zeta) - Momentum changes, GR = 0 - Momentum conserved
  • ζ4 (zeta) - Momentum changes, GR = 0 - Momentum conserved


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Notes:

1. The paper we read for this program (only sections 3 and 4):
2. My review of Will's book. This paper serves as something of an update of it. A true update is scheduled to come in December 2018.

3. Related Episodes of Physics Frontiers:

4. If you have any information about good packages for numerical relativity for Randy, please leave them in the comments.

5. Please visit and comment on our subreddit, and if you can help us keep this going by contributing to our Patreon, we'd be grateful.

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