Kinetically stabilized inflation

A bstract In this work, we propose a string-inspired two fields inflation model to address the fine-tuning problem that standard suffers. The fast-rolling tachyon $$ \mathcal{T} T originated from D-brane and anti-D-brane pair annihilation locks inflaton φ slowly rolling on Higgs-like potential V\left(\varphi \right)=-{m}_{\varphi}^2{\varphi}^2+\lambda {\varphi}^4 V φ = − m 2 + λ 4 drives kinetically stabilized (KS) inflation. Our numerical simulation confirms such solution is dynamic attractor. particular, for λ < 0 . 8 × 10 − 3 , e-folding number contributed by KS phase can be larger than 62 solve horizon flatness problems of Big Bang theory. Notably, generates nearly scale-invariant primordial curvature perturbations spectrum consistent with current cosmic microwave background (CMB) observations. It predicts low tensor-to-scalar ratio, which gravitational wave (the B-modes in CMB) searches favor.