Kinetically stabilized inflation

Abstract

Abstract In this work, we propose a string-inspired two fields inflation model to address the fine-tuning problem that the standard inflation model suffers. The fast-rolling tachyon T $$ \mathcal{T} $$ originated from the D-brane and anti-D-brane pair annihilation locks the inflaton φ slowly rolling on a Higgs-like potential V φ = − m φ 2 φ 2 + λ φ 4 $$ V\left(\varphi \right)=-{m}_{\varphi}^2{\varphi}^2+\lambda {\varphi}^4 $$ and drives a kinetically stabilized (KS) inflation. Our numerical simulation confirms such a solution is a dynamic attractor. In particular, for λ < 0.8 × 10 −3, the e-folding number contributed by the KS inflation phase can be larger than 62 to solve the horizon and flatness problems of Big Bang theory. Notably, this KS inflation generates a nearly scale-invariant primordial curvature perturbations spectrum consistent with current cosmic microwave background (CMB) observations. It predicts a low tensor-to-scalar ratio, which the current primordial gravitational wave background (the B-modes in CMB) searches favor.

Keywords

• Early Universe Particle Physics
• Tachyon Condensation
• String and Brane Phenomenology