Abstract

Inflation in the early universe can generate the nearly conformal invariant fluctuation that leads to the structures we observe at the present. The simple viable Starobinsky R² inflation has an approximate global scale symmetry. We study the conformal symmetric Weyl R² gravity and demonstrate its equivalence to Einstein gravity coupled with a scalar and a Weyl gauge field. The scalar field can be responsible for inflation with Starobinsky model as the attractor, potentially distinguishable from the latter by future experiments. The intrinsic Weyl gauge boson becomes massive once the Einstein frame is fixed, and constitutes as a dark matter candidate through gravitational production.

https://arxiv.org/pdf/2006.02811v1.pdf