Einstein Field Equation Question on Format

[NeutrinoWave]

Somebody please remind me what is the difference between the Einstein Field Equation written in Covariant form and the

Einstein Field Equation written in Contravariant form

ie I am used to seeing

G (mu nu) raised indices = 8*pi * T (mu nu) raised indices

but sometimes people write

G (mu nu) lowered indices = 8*pi * T (mu nu) lowered indices

I remember one forms and basis vectors from many eons ago, but would like a reminder what is the difference

Mathematically and Physically

is between the above two different formats for the Einstein Field Equations, thanks

[acey]

There's really no difference: it amounts to deciding whether you're going to write vectors as rows or columns. As long as you stay consistent you're fine.

Formally there's a difference but physically there isn't.

[Tiki]

Somebody please remind me what is the difference between the Einstein Field Equation written in Covariant form and the

Einstein Field Equation written in Contravariant form

Essentially jargon.

Contravariant and covariant are simply labels which are applied to vectors depending upon which way the components transform.

Two vector equations and one meaning.