Comment on String-Dominated Universe(SDU)

摘要

Theoretical prejudice favors the flat(k=0) cosmology, and the inflationary Universe scenario implements this prejudice in a natural way. For the k=0 model omega (defined as rho total/rho critical; rho total = rho NR + rho vac + rho R + rho S) = 1. However, observational data suggests: omega /sub OBS/ approx. = 0.2' +- 0.1', where +- 0.1 indicates the range of values reported. This discrepancy is known as the omega -problem. A number of solutions have been suggested: omega /sub OBS/ is determined by assuming that light (i.e., galaxies) traces mass - perhaps this assumption is not valid; omega /sub OBS/ is not sensitive to a smoothly-distributed component of mass density - perhaps most of the mass density resides in a smooth component. Candidates for the smooth component include: relativistic particles (rho/sub R/), a relic cosmological term (rho/sub vac/), and in a recent letter Vilenkin has suggested fast-moving strings. (ERA citation 10:003546)