Inflationary limits on the size of compact extra space

Abstract

We study restrictions imposed on the parameters of the Kaluza–Klein extra space supplied by the standard inflationary models. It is shown that the size of the extra space cannot be larger than [Formula: see text][Formula: see text]cm and the [Formula: see text]-dimensional Planck mass should be larger than [Formula: see text][Formula: see text]GeV. The validity of these estimates is discussed. We also study creation of stable excitations of scalar field as the result of the extra metric evolution.