Origin of the universe: A hint from Eddington-inspired Born-Infeld gravity

Abstract

We study the `initial state' of an anisotropic universe in Eddington-inspired Born-Infeld gravity filled with a scalar field, whose potential has various forms. With this purpose, the evolution of a spatially-flat, homogeneous anisotropic Kasner universe is studied. We find an exact evolution of universe for each scalar potential by imposing a maximal pressure condition. The solution is shown to describe the initial state of the universe. The state is regular if the scalar potential increases not faster than the quadratic power for large field values. We also show that the anisotropy does not raise any defect in early universe contrary to the case of general relativity.