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Loop integral parametrization
Schwinger parametrization is a technique for evaluating
loop integrals which arise from
Feynman diagrams with one or more loops.
Using the well-known observation that
Julian Schwinger noticed that one may simplify the integral:
for Re(n)>0.
Another version of Schwinger parametrization is:
which is convergent as long as and .
[1] It is easy to generalize this identity to n denominators.
See also
References
-
^ Schwartz, M. D. (2014). "33". Quantum Field Theory and the Standard Model (9 ed.). Cambridge University Press. p. 705.
ISBN
9781107034730.