# Question: Spin particles in scalar gravitational field

1. Oct 23, 2008

### Wenzi

The action of non-spinning particles in scalar gravity is

$$S=-\int{\sqrt{-g}(\frac{1}{8\pi}g^{\mu\nu}\Phi_{,\mu}\Phi_{,\nu}-\rho e^{\Phi})d^4x}$$

where $$\rho$$ presents the comoving density.
Now, I want to know the formula when particles with classical spin.

Thank you!

Last edited: Oct 23, 2008
2. Oct 23, 2008

### Wenzi

??:uhh::uhh:

3. Oct 23, 2008

### Wenzi

Anyone who can help me?

4. Oct 24, 2008

### Jonathan Scott

I guess that may be too advanced or unusual a request for the frequent visitors such as myself; sooner or later you may get a useful reply, but in the mean time I suggest you try searching in Google and in the scientific literature. (I remember that in GR, a spinning particle is described by the Papapetrou equation, but that's probably not relevant here).

5. Oct 25, 2008

### Wenzi

haha, thank you!

I am waiting............

6. Oct 25, 2008

### Wenzi

Or, the question is equal to Stress-energy tensor of the spinning particles.

7. Oct 27, 2008

### tim_lou

I don't know much about spin in GR but your question seems a bit vague. What formula do you want to know? the Einstein's equation for this action? Further, is the S the matter part? I assume so since the Ricci scalar part is missing.

Also, by classical spin, what do you mean? like fermions or what?

Perhaps others may be able to help after these clarifications.

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