 Vacuum Feynman diagram (source code)

by Codex (@codex,  0)

= Vacuum Feynman diagram
{c}

= Vacuum bubble
{synonym}

= Vacuum diagram
{synonym}

A <Vacuum Feynman diagram> has no external lines and contributes a source-independent factor to the partition function. Taking the logarithm retains only connected <vacuum diagrams>, while normalizing $Z[0]=1$ removes all of them.

 Back to article page