The Problem of Flatness of the Universe in the Uncertainty-mediated Inflationary Model

A self-consistent explanation of the approximately flat three-dimensional space is one of the major conceptual issues of any cosmological model, determining its viability and competitiveness among the various theoretical proposals. In particular, just the inability to resolve the problem of flatness was one of the reasons to reject the old “pre-inflationary” cosmological model and to change it by the inflationary scenario. Here, we briefly recall how the three-dimensional flatness can or cannot be explained in the various models of the early Universe and discuss in detail the case of uncertainty-mediated inflation, which was suggested in our previous paper [7]. As follows from our analysis, the approximately flat 3D space in the last-mentioned model can really be formed “dynamically,” starting from generic initial conditions. Taking into account that this model also well resolves the causality problems in the early Universe [8], the uncertainty-mediated inflation might be a reasonable alternative to other inflationary scenarios.