Microcanonical simulations in classical and quantum field theory

Thesis/Dissertation · Fri Jan 01 04:00:00 EST 1988

OSTI ID:7165997

Olson, D P

In the first part of this thesis, a stochastic adaptation of the microcanonical simulation method is applied to the numerical simulation of the Su-Schrieffer-Heeger Hamiltonian for polyacetylene, a one-dimensional polymer were fermion-boson interactions play a dominant role in the dynamics of the system. The pure microcanonical simulation method fails in the marginally ergodic case and a stochastic adaptation, the hybrid microcanonical method, is employed to resolve problems with ergodicity. The hybrid method is shown to be an efficient method for higher dimensional fermionic quantum systems. In the second part of this thesis, a numerical simulation of the evolution of a network of global cosmic strings is an expanding Robertson-Walker universe is carried out. The system is quenched through an order-disorder phase transition and the nature of the string distribution is examined. While the string distribution observed at the phase transition is in good agreement with earlier estimates, the simulation reveals that the dynamics of the strings are suppressed by interactions with the Goldstone field. The network decays by topological annihilation and no spatial correlations are observed at any point in the simulation.

• Research Organization: Illinois Univ., Urbana, IL (USA)
• OSTI ID: 7165997
• Country of Publication: United States
• Language: English

Related Subjects

645000* -- High Energy Physics
645400 -- High Energy Physics-- Field Theory
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
COMPOSITE MODELS
DATA
ERGODIC HYPOTHESIS
EXTENDED PARTICLE MODEL
FIELD THEORIES
HAMILTONIANS
HYDROCARBONS
HYPOTHESIS
INFORMATION
MATHEMATICAL MODELS
MATHEMATICAL OPERATORS
NUMERICAL DATA
NUMERICAL SOLUTION
ORGANIC COMPOUNDS
PARTICLE MODELS
POLYACETYLENES
POLYENES
QUANTUM FIELD THEORY
QUANTUM OPERATORS
QUARK MODEL
STRING MODELS
THEORETICAL DATA