Feynman rules in statistical mechanics

Summary A definition of normal product of Bose fields is given and it is shown that the average value of such a product over the grand canonical ensemble vanishes. The definition is useful when considering a relativistic electron gas in interaction with radiation since it very naturally leads to rul...
Ausführliche Beschreibung

Summary A definition of normal product of Bose fields is given and it is shown that the average value of such a product over the grand canonical ensemble vanishes. The definition is useful when considering a relativistic electron gas in interaction with radiation since it very naturally leads to rules of calculation similar to the ordinary Feynman rules. Ausführliche Beschreibung