Physics and cosmology of topological defects in spontaneously broken gauge theories

Thesis/Dissertation · Wed Jan 01 04:00:00 EST 1986

OSTI ID:6647917

Bennett, D P

Two topics in the physics and cosmology of topological defects that occur in spontaneously broken gauge theories are considered. The first investigation involves baryon number violation catalyzed by magnetic monopoles in grand unified theories (CUTs). The fine tuning that keeps the weak interaction scale much smaller the GUT scale is necessarily upset in the vicinity of a magnetic monopole, and this can give the quarks a large effective mass at the monopole core. In minimal GUTs, the small Yukawa couplings between the Weinberg-Salam Higgs and the light quarks keep the effective quark masses very small so baryon number violation is not suppressed. However, if the Yukawa couplings are larger than 10/sup -3/ (instead of the usual 10/sup -5/) or with the appropriate tuning of Higgs parameters, the quark masses can become large at the core preventing monopole inducted proton decay. The evolution of a system of cosmic strings is studied in the second investigation following an analytic formalism introduced by Kibble. It is shown that, in a radiation dominated universe, the fate of the string system depends sensitively on the fate of the closed loops that are produced by the interactions of very long strings. The evolution of strings in the matter dominated era and some potential problems with the numerical simulations of Albrecht and Turok are also discussed.

• Research Organization: Stanford Univ., CA (USA)
• OSTI ID: 6647917
• Country of Publication: United States
• Language: English

Related Subjects

645400* -- High Energy Physics-- Field Theory
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
BARYON NUMBER
BASIC INTERACTIONS
COMPOSITE MODELS
COSMOLOGY
COUPLING CONSTANTS
ELEMENTARY PARTICLES
EXTENDED PARTICLE MODEL
FIELD THEORIES
GRAND UNIFIED THEORY
GRAVITATIONAL INTERACTIONS
HIGGS MODEL
INTERACTIONS
MAGNETIC MONOPOLES
MASS SPECTRA
MATHEMATICAL MODELS
MATHEMATICS
MONOPOLES
PARTICLE MODELS
POSTULATED PARTICLES
QUARK MODEL
QUARKS
SPECTRA
STRING MODELS
SYMMETRY BREAKING
TOPOLOGY
UNIFIED GAUGE MODELS
UNIFIED-FIELD THEORIES