2+1-dimensional quantum field theories in the 1/N expansion

Miscellaneous · Sun Jan 01 00:00:00 EST 1989

OSTI ID:5464730

Park, S H

A study of d {equals} 2 {plus} 1 quantum field theories is provided through two simple examples; (1) O(N)-invariant non-linear {sigma} model and (2) four fermion interaction models. The author studies these models in the framework of the 1/N expansion. These models are non-renormalizable in the weak coupling expansion but becomes renormalizable in the 1/N expansion. The author gives explicit renormalizability proofs for both models. The 1/N expansion demonstrates systematically nonperturbative effects. The author focuses on investigating non-perturbative phenomena in both models, the two-phase structure in the non-linear O(N) invariant {sigma} model and dynamical symmetry breaking in the four fermion interaction models. In the non-linear {sigma} model we explicitly demonstrate how the classical constraint exhibits itself on the quantum level. The phase structure and correlation functions are calculated at zero and finite temperature, and are compared with recent numerical simulations. In four fermion models dynamical symmetry breaking is quantitatively studied. Dynamical breaking of both discrete and continuous symmetry are studied in detail. The effects of explicit symmetry breaking are also investigated.

• Research Organization: Texas Univ., Austin, TX (United States)
• OSTI ID: 5464730
• Resource Relation: Other Information: Thesis (Ph. D.)
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
QUANTUM FIELD THEORY
COMPARATIVE EVALUATIONS
CORRELATION FUNCTIONS
NONLINEAR PROBLEMS
PERTURBATION THEORY
RENORMALIZATION
SIGMA MODEL
SYMMETRY BREAKING
BOSON-EXCHANGE MODELS
FIELD THEORIES
FUNCTIONS
MATHEMATICAL MODELS
PARTICLE MODELS
PERIPHERAL MODELS
645400* - High Energy Physics- Field Theory