I have read that Einstein's formulation of gravity [tex]G_{ab}=\frac{8 \pi G}{c^4}T_{ab}[/tex] is analogous to the differential form of Newton's version [tex]\nabla ^2 \phi = 4 \pi G \rho[/tex] with the metric tensor and energy-momentum tensor in the modern form playing the same roles as gravitational potential and density in the classical one, respectively.(adsbygoogle = window.adsbygoogle || []).push({});

My question: why did the 4 become an 8?

**Physics Forums - The Fusion of Science and Community**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# About poisson's equation

Loading...

Similar Threads - poisson's equation | Date |
---|---|

Poisson, Einstein, Weak Energy Condition | Dec 27, 2015 |

Poisson bracket and Electric and Magnetic Weyl tensor in GR | Jul 31, 2013 |

Einstein's Field Equations and Poisson's Equation | Jan 16, 2011 |

Relativistci poisson brackets | Oct 15, 2009 |

Poisson brackets for Hamiltonian descriptions | Feb 5, 2009 |

**Physics Forums - The Fusion of Science and Community**