Anonymous at Sat, 26 Oct 2024 09:15:26 UTC No. 16450217

>>16450112
Le dark energy is the cosmological constant. It gives a negative, diagonal contribution to the stress-energy tensor, but isn’t derived from the matter terms in the action. Hence the term “negative vacuum energy-pressure”. It’s not gravity, because gravity itself is described by a rank-4 tensor (the Riemann tensor), while the cosmological constant is just a constant multiplied by a rank-2 tensor. It is simply the constant term in the action that becomes non-trivial in GR due to the integral measure being multiplied by the square root of the metric determinant.

Anonymous at Sat, 26 Oct 2024 09:20:44 UTC No. 16450220

>>16450217
oh okay, it all makes sense now :)