Wick theorem | Wikipedia audio article
Channel: wikipedia tts
Date: 2018-12-31

This is an audio version of the Wikipedia Article:
https://en.wikipedia.org/wiki/Wick%27s_theorem


00:00:39 1 Definition of contraction
00:09:08 2 Examples
00:12:56 2.1 Example 1
00:16:12 2.2 Example 2
00:19:52 2.3 Example 3
00:31:33 3 Statement of the theorem
00:41:48 4 Wick's theorem applied to fields
00:55:26 5 See also



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SUMMARY
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Wick's theorem is a method of reducing high-order derivatives to a combinatorics problem. It is named after Gian-Carlo Wick. It is used extensively in quantum field theory to reduce arbitrary products of creation and annihilation operators to sums of products of pairs of these operators. This allows for the use of Green's function methods, and consequently the use of Feynman diagrams in the field under study. A more general idea in probability theory is Isserlis’ theorem.