Feynman Diagrams and the S-Matrix and Outer Space - Summer 2020 - Exercise 6

Oct 26, 2026

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This document provides a set of theoretical physics exercises related to Feynman diagrams, the S-matrix, and graph theory, authored by Dirk Kreimer for the Summer 2020 course. The content focuses on the analysis of a specific graph structure, identified as a wheel with three spokes, which involves external and internal edges labeled from e1 to e10. Students are tasked with calculating the number of spanning trees, identifying all such trees, determining normal thresholds, and evaluating reduced graphs for the given system. Furthermore, the problem requires finding a complete refinement of vertices and external edges for a chosen spanning tree, challenging students to apply advanced mathematical concepts to quantum field theory representations. This exercise serves as a critical assessment tool for understanding the complexity of perturbative quantum field theory and the combinatorial properties inherent in Feynman diagrammatic expansions, reflecting academic standards at Humboldt University in Berlin.

LanguageEnglish

CategoryExam

FormatPDF

Pages1

Reading Time3 min

AccessFree to download

Exercise Overview

Problem 1: The Wheel with Three Spokes

Required Tasks

FAQs

What is the primary subject of the exercise?

The exercise concerns Feynman diagrams, the S-matrix, and their application to a specific graph structure described as a wheel with three spokes.

How many edges are involved in the diagram?

The graph includes external edges labeled e1 through e4 and internal edges labeled e5 through e10.

What are the specific tasks required for the wheel graph?

Students must count the spanning trees, identify them all, determine normal thresholds, evaluate reduced graphs, and find a complete refinement of vertices and external edges.

Oct 26, 2026

Upload by Đào