We consider the polynomial inflation with the tensor-to-scalar ratio as large as possible which can be consistent with the quantum gravity(QG) corrections and effective field theory(EFT). To get a minimal field excurs...We consider the polynomial inflation with the tensor-to-scalar ratio as large as possible which can be consistent with the quantum gravity(QG) corrections and effective field theory(EFT). To get a minimal field excursion ΔΦ for enough e-folding number N, the inflaton field traverses an extremely flat part of the scalar potential, which results in the Lyth bound to be violated. We get a CMB signal consistent with Planck data by numerically computing the equation of motion for inflaton Φ and using Mukhanov–Sasaki formalism for primordial spectrum. Inflation ends at Hubble slow-roll parameter ε_(1)^(H)=1 or a=0. Interestingly, we find an excellent practical bound on the inflaton excursion in the format a+b√r, where a is a tiny real number and b is at the order 1. To be consistent with QG/EFT and suppress the high-dimensional operators, we show that the concrete condition on inflaton excursion is M_(PI)/△_(Ф)<0.2×√10≈0.632. For n_(s)= 0.9649,N_(e)= 55, and M_(PI)/△_(Ф)<0.632 MPl, we predict that the tensor-to-scalar ratio is smaller than 0.0012 for such polynomial inflation to be consistent with QG/EFT.展开更多
基金supported in part by the Projects 11875062, 11875136, and 11947302supported by the National Natural Science Foundation of China+3 种基金the Major Program of the National Natural Science Foundation of China under Grant No. 11690021the Key Research Program of Frontier Science, CASsupported in part by the Program 2020JQ-804 supported by Natural Science Basic Research Plan in Shanxi Province of Chinathe Program 20JK0685 funded by Shanxi Provincial Education Department。
文摘We consider the polynomial inflation with the tensor-to-scalar ratio as large as possible which can be consistent with the quantum gravity(QG) corrections and effective field theory(EFT). To get a minimal field excursion ΔΦ for enough e-folding number N, the inflaton field traverses an extremely flat part of the scalar potential, which results in the Lyth bound to be violated. We get a CMB signal consistent with Planck data by numerically computing the equation of motion for inflaton Φ and using Mukhanov–Sasaki formalism for primordial spectrum. Inflation ends at Hubble slow-roll parameter ε_(1)^(H)=1 or a=0. Interestingly, we find an excellent practical bound on the inflaton excursion in the format a+b√r, where a is a tiny real number and b is at the order 1. To be consistent with QG/EFT and suppress the high-dimensional operators, we show that the concrete condition on inflaton excursion is M_(PI)/△_(Ф)<0.2×√10≈0.632. For n_(s)= 0.9649,N_(e)= 55, and M_(PI)/△_(Ф)<0.632 MPl, we predict that the tensor-to-scalar ratio is smaller than 0.0012 for such polynomial inflation to be consistent with QG/EFT.
