Hi all! I'm sorry if this question has been already asked in another post...(adsbygoogle = window.adsbygoogle || []).push({});

I'm studying the path integrals formalism in QED. I'm dealing with the functional generator for fermionic fields. My question is:

The generating functional is:

$$Z_0=e^{-i\int{d^4xd^4y \bar{J}(x)S(x-y)J(y)}}$$

Where $$J(x)$$ and $$\bar{J}(x)$$ are Grassmann numbers.

When I have to extract Green function from the generating functional I have to perform, for example, a functional derivative rispect to J(z). Does the functional derivative follow the same rule as the ordinary derivative? Do I have to anticommutate $$\bar{J}$$ and $$J$$ before deriving??

Thaks to all

Einj

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# Grassmann variables and functional derivatives

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