# Einstein Field Equation

1. Jan 21, 2016

### TimeRip496

2g00 = 8πGρ

According to drphysics, as this is not a tensor equation, we need to change it such that it fits general relativity.

Gμv = 8πGTμv

T00 is the energy density. The conversion of the density(ρ) to T00 is it done through E=mc2?

ρ=E/c2

And since is T00, it will be over c4 instead of c2. Is this how we add c4 to this equation(∇2g00 = 8πGρ) as we convert it to its tensor form?

Source:

2. Jan 22, 2016

### Staff: Mentor

The factor of $c^4$ is for unit conversion; it assumes that you are using conventional units of energy density for the RHS of the field equation and units of curvature (inverse length squared) for the LHS. A quantity with units of energy density is converted to units of curvature by multiplying by $G / c^4$. (If the RHS is in units of mass density instead, the factor will be $G / c^2$.)