Cluster Expansion Approach to Non-Abelian Lattice Gauge Theory.

Available from UMI in association with The British Library. In this thesis linked cluster expansion methods are used to extend strong coupling series for the vacuum energy density, the axial string tension and the scalar mass gap for the SU(2) Hamiltonian lattice gauge model in (3 + 1) dimensions. The related ELCE algorithm is used to calculate the string tension beyond its roughening transition. From the expected continuum scaling behaviour we estimate the string tension sigma^{1/2} cong 0.6 Lambda _{rm mom} and the scalar glueball mass m_{rm s} cong 2Lambda_ {rm mom}. The string tension result is in good agreement with recent Monte Carlo estimates although the mass gap is somewhat lower although not inconsistent in view of the large uncertainties.