# Demonstrated convincingly that supergravity gives you GR

1. Jul 19, 2010

### hamster143

Has it ever been demonstrated convincingly that supergravity gives you GR in the continuum limit (as opposed to just some massless spin-2 field)?

Where can I find a readable derivation of this fact?

2. Jul 19, 2010

### Haelfix

Re: Supergravity

What do you mean by 'GR' exactly? The exact equations of motion?

Supergravity is more than GR in a sense, and depending on how you arrange things its not necessarily trivial to decouple them. The local spacetime symmetry group is enhanced and there are unavoidable matter d.o.f propogating around (in a sense they have to be there, and aren't put in by hand).

However, in the limit where supersymmetry is broken and the heavy degrees of freedom are integrated out or moved over into the matter portion of the lagrangian, than yea you can get the usual Einstein theory of gravity in the classical limit.

Last edited: Jul 19, 2010
3. Jul 19, 2010

### hamster143

Re: Supergravity

The derivation of classical lagrangian with $R$'s and $\sqrt{-g}$'s would suffice.

Somehow by examining relevant chapters in e.g. Weinberg, I get the impression that all we really get is linearised gravity instead.

4. Jul 19, 2010

### Haelfix

Re: Supergravity