Kinoshita–Lee–Nauenberg theorem

The Kinoshita–Lee–Nauenberg theorem or KLN theorem states that perturbatively the Standard Model as a whole is infrared (IR) finite. That is, the infrared divergences coming from loop integrals are canceled by IR divergences coming from phase space integrals. It was introduced independently by and .

An analogous result for quantum electrodynamics alone is known as Bloch–Nordsieck theorem.

Ultraviolet divergences in perturbative quantum field theory are dealt with in renormalization.

References

• Taizo Muta, Foundations of Quantum Chromodynamics: An Introduction to Perturbative Methods in Gauge Theories, World Scientific Publishing Company; 3 edition (September 30, 2009)