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Results tagged with correlation-functions
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user 21270
A correlation function is a statistical correlation between random variables at two different points in space, time, or other parameter space, usually as a function of the variable distance between these points. In QFT, field autocorrelation functions are propagators, so use the "propagator" tag, instead.
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Relation between Green’s functions and connected Green’s functions
From the given expression for $C_n$ we can write,
$$C_n = \left[ \frac{\partial^n W(J)}{\partial J^n}\right]_{J=0},$$
where $W(J) = \ln Z(J) = \ln \left[\sum_{n=0}^{\infty}\frac{1}{n!} J^n G_n\right]$ …
- 3,053
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Relation between Green’s functions and connected Green’s functions [closed]
I attempt to understand the $0$-dimensional QFT from these QFT lecture notes by Ronald Kleiss from 2019. The author defines the generating function $Z(J)$ and its logarithm in the following way.
$$Z(J …
- 3,053