The Renormalization Group According to Balaban - III. Convergence

This is an expository account of Balaban's approach to the renormalization group. The method is illustrated with a treatment of the ultraviolet problem for the scalar phi^4 model on a toroidal lattice in dimension d=3. In this third paper we demonstrate convergence of the expansion and complete the proof of a stability bound.Comment: 37 page

The Renormalization Group According to Balaban - I. Small fields

This is an expository account of Balaban's approach to the renormalization group. The method is illustrated with a treatment of the the ultraviolet problem for the scalar phi^4 model on a toroidal lattice in dimension d=3. This yields another proof of the stability bound. In this first paper we analyze the small field contribution to the partition function.Comment: 52 pages. Some corrections, additions, reorganizatio

The Dirac Sea

We give an alternate definition of the free Dirac field featuring an explicit construction of the Dirac sea. The treatment employs a semi-infinite wedge product of Hilbert spaces. We also show that the construction is equivalent to the standard Fock space construction.Comment: 7 page

Sine-Gordon Revisited

We study the sine-Gordon model in two dimensional space time in two different domains. For beta > 8 pi and weak coupling, we introduce an ultraviolet cutoff and study the infrared behavior. A renormalization group analysis shows that the model is asymptotically free in the infrared. For beta < 8 pi and weak coupling, we introduce an infrared cutoff and study the ultraviolet behavior. A renormalization group analysis shows that the model is asymptotically free in the ultraviolet.Comment: 43 pages, Latex 2.0