STRUCTURE FORMATION FROM POWER LAW (AND EXTENDED) INFLATION

In models of inflation where the expansion rate is slower than exponential, scale invariance is broken and the primeval density spectrum is no longer flat. We consider power law inflation models (of which extended inflation provides a specific example) where the scale factor increases like a power p of the time. They give a spectrum which increases like a power 2/(p - 1) of the scale. A power p approximately 5 in a cold dark matter universe can explain recent observations of the galaxy angular correlation function without violating published limits on the microwave anisotropy. The formation of nonlinear structure occurs more recently than in standard CDM. One can calculate the inflationary energy scale, which is much lower than the energy scale of structure forming topological defects.