Collective coordinates for nonlinear Klein-Gordon field theories

Thesis/Dissertation · Thu Jan 01 04:00:00 EST 1987

OSTI ID:6989153

Flesch, R J

In this dissertation, the dynamics of kink solitons in perturbed nonlinear Klein-Gordon models are studied, using a collective coordinate which represents the kind position as a function of time. The center of mass of the kink is found to obey Newtonian dynamics. Radiation of phonons which are produced by the interaction of the kink with the perturbation are calculated with the aid of Green functions which are derived for the sine-Gordon, Phi/sup 4/, and double quadratic nonlinear Klein-Gordon potentials. The influence of this emitted radiation on the motion of the kink is also studied. Again, utilizing the collective coordinate for the kink position, the effects of thermal noise and damping are investigated via both Langevin and Fokker-Planck methods. In lowest order, it was found that the kink behaves as a regular Brownian particle. Higher-order corrections yield a temperature-dependent mass and diffusion constant. Finally, the collision of a Phi/sup 4/ kink with a Phi/sup 4/ antikink is investigated by an averaged Lagrangian technique.

• Research Organization: University of Southern California, Los Angeles (USA)
• OSTI ID: 6989153
• Country of Publication: United States
• Language: English

Related Subjects

645400* -- High Energy Physics-- Field Theory
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
COORDINATES
DIFFERENTIAL EQUATIONS
EQUATIONS
FIELD EQUATIONS
FIELD THEORIES
FUNCTIONS
GREEN FUNCTION
KLEIN-GORDON EQUATION
NONLINEAR PROBLEMS
PARTIAL DIFFERENTIAL EQUATIONS
QUASI PARTICLES
SINE-GORDON EQUATION
SOLITONS
WAVE EQUATIONS