Extended structures at intermediate scales in an inflationary cosmology

Abstract

In an inflationary cosmology the phase transitions associated with intermediate mass scales may experience a large though not huge number of e-foldings before being finally completed. Extended structures (monopoles, strings, etc.) arising from such transitions are not necessarily inflated away. In an SO(10) model. for example, magnetic monopoles with mass ∼ 10 13−10 14 GeV can occur at a level which is experimentally detectible. The topologically unstable string-wall system of axion models provides an important source of density fluctuations as a consequence of inflation.