hide
Free keywords:
High Energy Physics - Theory, hep-th,Astrophysics, Cosmology and Extragalactic Astrophysics, astro-ph.CO
Abstract:
In the framework of scalar-tensor theories of gravity, we construct a new
kind of cosmological model that conflates inflation and ekpyrosis. During a
phase of conflation, the universe undergoes accelerated expansion, but with
crucial differences compared to ordinary inflation. In particular, the
potential energy is negative, which is of interest for supergravity and string
theory where both negative potentials and the required scalar-tensor couplings
are rather natural. A distinguishing feature of the model is that it does not
amplify adiabatic scalar and tensor fluctuations, and in particular does not
lead to eternal inflation and the associated infinities. We also show how
density fluctuations in accord with current observations may be generated by
adding a second scalar field to the model. Conflation may be viewed as
complementary to the recently proposed anamorphic universe of Ijjas and
Steinhardt.
