http://arxiv.org/abs/2111.07835
We derive the power spectrum of primordial quantum fluctuations in an inflationary universe for curvature parameter ${\mathcal K}=1$. This is achieved through a Born–Oppenheimer type of approximation scheme from the Wheeler–DeWitt equation of canonical quantum gravity using gauge-invariant variables. Compared to the flat model, the closed model exhibits a deficit of power at large scales.
C. Kiefer and T. Vardanyan
Tue, 16 Nov 21
4/97
Comments: 18 pages, 1 figure, Invited contribution to a Topical Collection for the GRG journal in memory of Prof. T. Padmanabhan