PREPRINT

On the superstring-inspired quantum correction to the Starobinsky model of inflation

Sergei V. Ketov, Ekaterina O. Pozdeeva, Sergey Yu. Vernov

Submitted on 2 November 2022

Abstract

Superstring/M-theory is the theory of quantum gravity that can provide the UV-completion to viable inflation models. We modify the Starobinsky inflation model by adding the Bel-Robinson tensor Tμνλρ squared term proposed as the leading quantum correction inspired by superstring theory. The (R+16m2R2β8m6T2) model under consideration has two parameters: the inflaton mass m and the string-inspired positive parameter β. We derive the equations of motion in the Friedmann-Lemaitre-Robertson-Walker universe and investigate its solutions. We find the physical bounds on the value of the parameter β by demanding the absence of ghosts and consistency of the derived inflationary observables with the measurements of the cosmic microwave background radiation.

Preprint

Comment: 22 pages, 5 figures, LaTeX

Subjects: General Relativity and Quantum Cosmology; Astrophysics - Cosmology and Nongalactic Astrophysics; High Energy Physics - Theory

URL: http://arxiv.org/abs/2211.01546

The functions $h(\tau)$ (on the left), $R_h(\tau)$ (in the center) for different initial conditions, and the phase portrait $(R_h,h)$  (on the right) in the Starobinsky $(R+R^2)$ gravity model of inflation.