TY  - JOUR
A1  - Benisty, David
A1  - Guendelman, Eduardo I.
A1  - Nissimov, Emil
A1  - Pacheva, Svetlana
T1  - Dynamically generated inflationary two-field potential via non-Riemannian volume forms
T2  - Nuclear Physics B
N2  - We consider a simple model of modified gravity interacting with a single scalar field ϕ with weakly coupled exponential potential within the framework of non-Riemannian spacetime volume-form formalism. The specific form of the action is fixed by the requirement of invariance under global Weyl-scale symmetry. Upon passing to the physical Einstein frame we show how the non-Riemannian volume elements create a second canonical scalar field u and dynamically generate a non-trivial two-scalar-field potential Ueff(u,ϕ) with two remarkable features: (i) it possesses a large flat region for large u describing a slow-roll inflation; (ii) it has a stable low-lying minimum w.r.t. (u,ϕ) representing the dark energy density in the “late universe”. We study the corresponding two-field slow-roll inflation and show that the pertinent slow-roll inflationary curve ϕ = ϕ(u) in the two-field space (u,ϕ) has a very small curvature, i.e., ϕ changes very little during the inflationary evolution of u on the flat region of Ueff(u,ϕ). Explicit expressions are found for the slow-roll parameters which differ from those in the single-field inflationary counterpart. Numerical solutions for the scalar spectral index and the tensor-to-scalar ratio are derived agreeing with the observational data.
Y1  - 2019
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/53605
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-536050
SN  - 1873-1562
SN  - 0550-3213
VL  - 951.2020
IS  - 114907
PB  - Elsevier
CY  - Amsterdam
ER  -