From bcae81336764eb6c4cdf0f91e2fe632b625dd8b2 Mon Sep 17 00:00:00 2001 From: Prefetch Date: Sun, 23 Oct 2022 22:18:11 +0200 Subject: Optimize and improve naming of all images in knowledge base --- source/know/concept/self-energy/index.md | 12 +++--------- 1 file changed, 3 insertions(+), 9 deletions(-) (limited to 'source/know/concept/self-energy/index.md') diff --git a/source/know/concept/self-energy/index.md b/source/know/concept/self-energy/index.md index 005f135..f233466 100644 --- a/source/know/concept/self-energy/index.md +++ b/source/know/concept/self-energy/index.md @@ -204,9 +204,7 @@ that exactly $$2^m m!$$ diagrams at each order are topologically equivalent, so we are left with non-equivalent diagrams only. Let $$G(b,a) = G_{ba}$$: - - - +{% include image.html file="expansion.png" width="90%" alt="Full expansion of G in Feynman diagrams" %} A **reducible diagram** is a Feynman diagram that can be cut in two valid diagrams @@ -217,9 +215,7 @@ At last, we define the **self-energy** $$\Sigma(y,x)$$ as the sum of all irreducible terms in $$G(b,a)$$, after removing the two external lines from/to $$a$$ and $$b$$: - - - +{% include image.html file="definition.png" width="90%" alt="Definition of self-energy" %} Despite its appearance, the self-energy has the semantics of a line, so it has two endpoints over which to integrate if necessary. @@ -238,9 +234,7 @@ Thanks to this recursive structure, you can convince youself that $$G(b,a)$$ obeys a [Dyson equation](/know/concept/dyson-equation/) involving $$\Sigma(y, x)$$: - - - +{% include image.html file="dyson.png" width="95%" alt="Dyson equation in Feynman diagrams" %} This makes sense: in the "normal" Dyson equation we have a one-body perturbation instead of $$\Sigma$$, -- cgit v1.2.3