Potential for the slow-roll inflation, mass scale hierarchy and Dark Energy from the Type IIA supergravity

TL;DR

This paper explores how Type IIA supergravity with fluxbrane solutions can naturally produce slow-roll inflation, explain the mass hierarchy, and account for Dark Energy through radion potential dynamics and throat geometry.

Contribution

It introduces a stabilized extra-dimensional setup with a radion potential that supports inflation and links Dark Energy to the geometry of warped throats in supergravity.

Findings

Radion potential decreases exponentially in the slow-roll region.

Constructs IR end of the throat with tiny positive radion potential.

Derives relation between Dark Energy density and mass hierarchy: ρ_{D.E.} ∼ G_N^2 m^8.

Abstract

The magnetic fluxbrane solution with a strongly warped throat is studied in the Type IIA supergravity theory with co-dimension one local source which surves as $Z_{2}$-symmetric UV boundary of the throat. Overall volume of extra space is stabilized since introduction of the local source breaks the no-scale structure of the theory and evades the no-go theorem. Radion field is defined as the position of UV boundary "moved" from its stable value fixed by the anisotropic Israel junction conditions. Analytical expression for the radion effective potential is received. Potential decreases exponentially (exponent is equal to 0,21 in Planck units) in the slow-roll region and apparently meets other demands of the early inflation. Reissner-Nordstrom type deformation of the elementary fluxbrane solution permits to construct the IR end of the throat and results in tiny positive non-zero value of the radion potential in its extremal point seen today as Dark Energy $\rho_{D.E.}$. Expressions for the mass scale hierarchy and for the "acceleration hierarchy" received in the paper give the physically interesting relation between two hierarchies: $\rho_{D.E.} \sim G_{N}^{2}m^{8}$.