Implementing unitarity in perturbation theory
نویسندگان
چکیده
منابع مشابه
Implementing Unitarity in Perturbation Theory
Unitarity cannot be perserved order by order in ordinary perturbation theory because the constraint UU † = 1 is nonlinear. However, the corresponding constraint for K = ln U , being K = −K†, is linear so it can be maintained in every order in a perturbative expansion of K. The perturbative expansion of K may be considered as a non-abelian generalization of the linked-cluster expansion in probab...
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ژورنال
عنوان ژورنال: Physical Review D
سال: 2001
ISSN: 0556-2821,1089-4918
DOI: 10.1103/physrevd.63.097901