---
layout: default
---
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/11.9.0/styles/default.min.css">
<script src="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/11.9.0/highlight.min.js"></script>

<script type="text/javascript" charset="UTF-8"
  src="../assets/css/lean.min.js"></script>
<script>hljs.highlightAll();</script>
<!-- Note header (title, curators, notice etc.). -->
<center><h1 style="font-size: 50px;">{{ site.data.perturbationTheory.title }}</h1></center>
<center><h2 style="font-size: 20px;">Note Curators: {{ site.data.perturbationTheory.curators }}</h2></center>

<br>
<div style="border: 1px solid black; padding: 10px;">
  <p>Note:
  These notes are created using an interactive theorem
  prover called <a href="https://lean-lang.org">Lean</a>.
  Lean formally checks definitions, theorems and proofs for correctness.
  These notes are part of a much larger project called
  <a href="https://github.com/HEPLean/HepLean">HepLean</a>, which aims to digitalize
  high energy physics into Lean. Please consider contributing to this project.
  <br><br>
  Please provide feedback or suggestions for improvements by creating a GitHub issue
  <a href="https://github.com/HEPLean/HepLean/issues">here</a>.
  </p>
</div>
<!-- Table of content. -->
<hr>
<center><h2 style="font-size: 30px;">Table of content</h2></center>
<p>
{% for entry in site.data.perturbationTheory.parts %}
{% if entry.type == "h1" %}
  {{ entry.sectionNo }}. {{ entry.content }}<br>
{% endif %}
{% if entry.type == "h2" %}
  - {{ entry.sectionNo }}. {{ entry.content }}<br>
{% endif %}
{% endfor %}
</p>
<hr>
<!-- Main body. -->
<br>
{% for entry in site.data.perturbationTheory.parts %}
  {% if entry.type == "h1" %}
    <h1>{{ entry.sectionNo }}. {{ entry.content }}</h1>
  {% endif %}
  {% if entry.type == "h2" %}
    <h2>{{ entry.sectionNo }}. {{ entry.content }}</h2>
  {% endif %}
  {% if entry.type == "p" %}
    <p>{{ entry.content }}</p>
  {% endif %}
  {% if entry.type == "name" %}

  <div style="background-color: #f5f5f5; padding: 10px; border-radius: 4px;">
    <p> <a href = "{{ entry.link }}" style="font-weight: bold; color: #2c5282;">{{ entry.name }}</a>: {{ entry.docString | markdownify}}</p>
    <details class="code-block-container">
    <summary>Show Lean code:</summary>
    <pre style="background: none; margin: 0;"><code class="language-lean">{{ entry.declString }}</code></pre>
    </details>
  </div>
  <br>

  {% endif %}
  {% if entry.type == "remark" %}
  <div style="padding: 10px; border-radius: 4px; border: 1px solid #e8e6e6;">
    <a href = "{{ entry.link }}" style="color: #2c5282;">Remark: {{ entry.name}} </a>
  {{ entry.content|markdownify }}
  </div>
  <br>
  {% endif %}
{% endfor %}