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Feynman graphs for non-Gaussian measures

S. H. Djah·H. Gottschalk·H. Ouerdiane
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Abstract

Partition- and moment functions for a general (not necessarily Gaussian) functional measure that is perturbed by a Gibbs factor are calculated using generalized Feynman graphs. From the graphical calculus, a new notion of Wick ordering arises, that coincides with orthogonal decompositions of Wiener-Itô type only if the measure is Gaussian. Proving a generalized linked cluster theorem, we show that the logarithm of the partition function can be expanded in terms of connected Feynman graphs ("linked cluster theorem").

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S. H. Djah, H. Gottschalk, H. Ouerdiane. 2006-11-30. Feynman graphs for non-Gaussian measures. https://arxiv.org/abs/math-ph/0501030

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