There are '''commonCommon integrals in quantum field theory''' thatare appearall repeatedlyvariations and generalizations of [[Gaussian integral|Gaussian integrals]] to the complex plane and to multiple dimensions.<ref>{{cite book|author=A. Zee|title=Quantum Field Theory in a Nutshell|publisher=Princeton University|year=2003|isbn=0-691-01019-6}} pp. 13-15</ref> These integrals are all variations and generalizations of [[Gaussian integral|Gaussian integrals]] to the complex plane and to multiple dimensions. Other integrals can be approximated by versions of the Gaussian integral. Fourier integrals are also considered.
