Action principle of Bogoliubov coefficients

✍ Scribed by Jan Ambjørn; R.J Hughes; N.K Nielsen

• Book ID: 102987325
• Publisher: Elsevier Science
• Year: 1983
• Tongue: English
• Weight: 892 KB
• Volume: 150
• Category: Article
• ISSN: 0003-4916
• DOI: 10.1016/0003-4916(83)90005-2

✦ Synopsis

It is shown that the Schwinger action principle uniquely determines the Bogoliubov coefficients connecting in and out-states for an oscillator with a time-dependent spring constant. and hence for a charged particle field in a constant homogeneous electric field. This allows a complete construction of the S-matrix in the external field approximation. Especially it allows an easy calculation of (out 1 in), the vacuum-to-vacuum amplitude, in this approximation. The method is applied to electromagnetism embedded in a non-abelian gauge group.