Quadratic divergences in dimensional renormalization of 1/N expansions
We calculate the ultraviolet divergences of the scalar O(N) model in the 1/N expansion near four dimensions (d = 4-epsilon). At next to leading order in (1/N) the point d = 4 becomes an essential singularity as the accumulation point of an infinite sequence of poles at epsilon = 2/k for integer k. Such singular behavior renders the dimensionally renormalized interacting theory unsummable. These singularities are not predicted when the perturbatively calculated renormalization constants are reexpanded in powers of 1/N. Rather they arise from the summation of the infinite subset of quadratically divergent Feynman diagrams which make up each order of the 1/N expansion. Such pathological behavior should be a general feature of dimensional renormalization when quadratic divergences are treated nonperturbatively.
- Research Organization:
- Department of Physics, Chonbug National University, Chonju 520, R. O. Korea
- OSTI ID:
- 6197790
- Journal Information:
- Phys. Rev. D; (United States), Vol. 32:12
- Country of Publication:
- United States
- Language:
- English
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