Cosmological Effects of Superconducting Strings.

Superconducting cosmic strings can dramatically alter the evolution of the matter-dominated universe. In the presence of an ordered primeval magnetic field, each loop powers a blast wave which can be as large as the voids observed in the distribution of galaxies. The field's strength is similar to that needed to build galactic fields without dynamo amplification. The string network releases energy continuously. Galaxies form only when baryonic matter can move freely through the CBR and can cool from x-ray temperatures. Heating by strings at z ~ 10^2 -10^5 causes the CBR spectrum significantly to exceed a blackbody in the Wien limit. The predicted angular fluctuations in the CBR are relatively small, because most of the heating occurs while the universe is opaque. Many details of the dynamics of classical strings are special to four spacetime dimensions. We emphasize the crucial role of kinks. We argue that each loop initially carries a 'fractal' distribution of kinks. We discuss the fragmentation of cosmic string loops, including the possibility of a cascade into microscopic fragments. We exploit the (incomplete) analogy between the dynamics of superconducting strings and Einstein-Maxwell strings. We estimate the rate at which charge carriers are lost from cusps. We calculate the critical current for a bosonic superconducting string. We calculate the current induced on the string in a background magnetic field. The string traps plasma; each loop loses energy in a relativistic plasma wind. AC current modes are damped. Loops do not act as dynamos. The gravity wave background from the strings is reduced by electromagnetic losses and fragmentation. We discuss how a loop loses energy to the CBR when the universe is radiation-dominated. Self-similar solutions for string-driven blast waves allow us to set constraints on the parameters of the model. A loop with a large peculiar velocity drives a tubular blast wave. We calculate the radius at which a blast stalls, if the universe is open or contains dark matter, including radiative losses. The present peculiar velocities of the expanding shells are small; in an explosion model, the observed velocity field is gravitational in origin.