Retrieving "Diffeomorphism Constraint" from the archives

Cross-reference notes under review

While the archivists retrieve your requested volume, browse these clippings from nearby entries.

1. Einstein Field Equations

   Linked via "Diffeomorphism constraint"

   Constraint Equations
   While the EFE look like 10 equations, two are redundant due to the conservation of stress-energy ($\nabla^\mu T_{\mu\nu} = 0$), reducing the number of independent equations to eight for describing the metric. The remaining constraints, known as the Hamiltonian constraint and the Diffeomorphism constraint, govern how the geometry can evolve in time, ensuring that physics remains consistent regardless of the choice of time coordinate (coordinate independence).
   ---