Formulating the Kramers problem in field theory

Understand

The escape problem is defined in the context of quantum field theory.

• The escape rate is explicitly derived for a scalar field governed by fluctuation-dissipation dynamics, through generalizing the standard Kramers problem.
• In the presence of thermal fluctuations, there is a nonvanishing probability for a classical background field, initially located at a minimum of its potential in a homogeneous configuration, to escape from the well.
• The simple and well-known related problem of the escape of a classical point particle due to random forces is first reviewed.