1202.1368 (Renata Jora)

Do we need Feynman diagrams for higher orders perturbation theory?    [PDF]

Renata Jora

We compute the two loop corrections to the beta function for Yang-Mills
theories in the background gauge field method and using the background gauge
field as the only source. The calculations are based on the separation of the
one loop effective potential into zero and positive modes and are entirely
analytical. No two loop Feynman diagrams are considered in the process.

View original: http://arxiv.org/abs/1202.1368