https://doi.org/10.1140/epjc/s10052-019-7310-6
Regular Article - Theoretical Physics
Dynamically generated inflation from non-Riemannian volume forms
1
Physics Department, Ben-Gurion University of the Negev, 84105, Beer-Sheva, Israel
2
Frankfurt Institute for Advanced Studies (FIAS), Ruth-Moufang-Strasse 1, 60438, Frankfurt am Main, Germany
3
Bahamas Advanced Study Institute and Conferences, 4A Ocean Heights, Hill View Circle, Stella Maris, Long Island, Bahamas
4
Institute for Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, Sofia, Bulgaria
* e-mail: benidav@post.bgu.ac.il
Received:
16
June
2019
Accepted:
15
September
2019
Published online:
28
September
2019
We propose a simple modified gravity model without any initial matter fields in terms of several alternative non-Riemannian spacetime volume elements within the metric (second order) formalism. We show how the non-Riemannian volume-elements, when passing to the physical Einstein frame, create a canonical scalar field and produce dynamically a non-trivial inflationary-type potential for the latter with a large flat region and a stable low-lying minimum. We study the evolution of the cosmological solutions from the point of view of theory of dynamical systems. The theory predicts the spectral index and the tensor-to-scalar ratio
for 60 e-folds, which is in accordance with the observational data. In the future Euclid and SPHEREx missions or the BICEP3 experiment are expected to provide experimental evidence to test those predictions.
© The Author(s), 2019