Early Universe models from Noncommutative Geometry
  We investigate cosmological predictions on the early universe based on the
noncommutative geometry models of gravity coupled to matter. Using the
renormalization group analysis for the Standard Model with right handed
neutrinos and Majorana mass terms, which is the particle physics content of the
most recent noncommutative geometry models, we analyze the behavior of the
coefficients of the gravitational and cosmological terms in the Lagrangian
derived from the asymptotic expansion of the spectral action functional of
noncommutative geometry. We find emergent Hoyle-Narlikar and conformal gravity
at the see-saw scales and a running effective gravitational constant, which
affects the propagation of gravitational waves and the evaporation law of
primordial black holes and provides Linde models of negative gravity in the
early universe. The same renormalization group analysis also governs the
running of the effective cosmological constant of the model. The model also
provides a Higgs based slow-roll inflationary mechanism, for which one can
explicitly compute the slow-roll parameters. The particle physics content
allows for dark matter models based on sterile neutrinos with Majorana mass
terms.
