Nonstandard analysis in classical physics and quantum formal scattering (Q1106206)

It is shown that nonstandard analysis allows to avoid limit procedures in the expressions for a Green function etc.: namely, expressions like \(x+/0\), that are usually understood as \(\lim (x+a)\) as a tends to 0, \(a\to 0\), can be changed to \(x+a\), where a is a positive infinitesimal number.