# Gravitons and the Field Theory Metric

#### QuantumClue

We know the background metric has the description;

$$g_{\mu \nu}\sim\eta_{\mu \nu}+h_{\mu \nu}$$

I would like to know what the physical meaning is of the difference then?

$$h_{\mu \nu} - \eta_{\mu \nu}$$

When I've read field theories describing gravitons, they are usually denoted as:

$$h_{\mu \nu}$$

Where it can be seen as a perturbation on the background relation making it a fluctuation. I also know that the background metric can also be made to vanish by taking some form of diffeomorphism perhaps (?) not sure, I'll need to check that. But what is the significant meaning of taking the difference, does it produce a constant?

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"Gravitons and the Field Theory Metric"

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