Feynman Diagrams

Last updated
Save as PDF

Page ID: 38400

\( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \) \( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash {#1}}} \)\(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\) \(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\)\(\newcommand{\AA}{\unicode[.8,0]{x212B}}\)

Probing

Richard Feynman

Feynman Diagrams

Richard Feynman is well known for his contribution in Quantum Electrodynamics and awarded the Nobel Prize in physics in 1965. He is the inventor of Feynman Diagrams, a graphical representation to illustrate the space-time interactions of partical for the public to understand.

General Rules

In a quantum transition from an initial state to a final state, the contribution to the amplitude function can be calculated from Feynman diagram.

Feynman diagram consists of points (known as vertices) and lines connected two vertices.

The space and time dimensions are represented by "x" and "y" axis respectively.

Electron in the initial state is represented by a straight solid line arrow pointing toward a vertex \(\arrow\) and in final state is represented by a straight solid line arrow pointing away from the vertex (\arrow).

Positron in the initial state is represented by a solid straight line arrow pointing away from the vertex and solid straight line arrow pointing toward the vertex is positron in the final state.

Photon is represented by wavy lines towared the vertex or from the vertex represents the initial and the final state (~• and •~).

Contributors and Attributions

Chung (Peter) Chieh (Professor Emeritus, Chemistry @ University of Waterloo)
Sudarson S Sinha (Tel Aviv University)