Partition function (mathematics): Difference between revisions

Revision as of 22:41, 27 September 2013

Revision as of 22:42, 27 September 2013

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as the expectation value of <math>x_k</math>. In the [[path integral formulation]] of [[quantum field theory]], these auxiliary functions are commonly referred to as [[source field]]s.

Multiple differentiations lead to the [[connected correlationUrsell function|Ursellconnected correlation function]]s of the random variables. Thus the correlation function <math>C(x_j,x_k)</math> between variables <math>x_j</math> and <math>x_k</math> is given by:

:<math>C(x_j,x_k) = \left.