Schwinger 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

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References

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  1. ^ Schwartz, M. D. (2014). "33". Quantum Field Theory and the Standard Model (9 ed.). Cambridge University Press. p. 705. ISBN 9781107034730.