Regular Article - Theoretical Physics
On the perturbation theory in spatially closed background
Department of Physics, School of Sciences, Tarbiat Modares University, P.O. Box 14155-4838, Tehran, Iran
* e-mail: email@example.com
Accepted: 14 May 2014
Published online: 4 June 2014
In this article, we investigate some features of the perturbation theory in a spatially closed universe. We will show that the perturbative field equations in a spatially closed universe always have two independent adiabatic solutions provided that the wavelengths of perturbation modes are very much longer than the Hubble horizon. It will be revealed that these adiabatic solutions do not depend on the curvature directly. We also propose a new interpretation for the curvature perturbation in terms of the unperturbed background geometry.
© SIF and Springer-Verlag Berlin Heidelberg, 2014