Scale invariance and a gravitational model with non-eternal inflation

Carlos Herdeiro, Shinji Hirano
2012 Journal of Cosmology and Astroparticle Physics  
We propose a 3 + 1 dimensional model of gravity which results in inflation at early times, followed by radiation- and matter-dominated epochs and a subsequent acceleration at late times. Both the inflation and late time acceleration are nearly de Sitter with a large hierarchy between the effective cosmological constants. There is no scalar field agent of inflation, and the transition from the inflation to the radiation-dominated period is smooth. This model is designed so that it yields, at the
more » ... cost of giving up on Lorentz invariance in the gravitational sector, the Dirac-Born-Infeld type conformal scalar theory when the universe is conformally flat. It, however, resembles Einstein's gravity with the Gibbons-Hawking-York boundary term in weakly curved space-times.
doi:10.1088/1475-7516/2012/05/031 fatcat:mzismlochrdp7dk74xjqf7lhkm