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Diffstat (limited to 'source/know/concept/self-energy')
| -rw-r--r-- | source/know/concept/self-energy/index.md | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/source/know/concept/self-energy/index.md b/source/know/concept/self-energy/index.md index f233466..4120011 100644 --- a/source/know/concept/self-energy/index.md +++ b/source/know/concept/self-energy/index.md @@ -204,7 +204,8 @@ 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" %} +{% 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 @@ -215,7 +216,8 @@ 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" %} +{% include image.html file="definition.png" width="90%" + alt="Definition of the 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. @@ -234,7 +236,8 @@ 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" %} +{% 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 $$\Sigma$$, |