We investigate the constant-roll inflation with non-minimally kinetic coupling to the Einstein tensor.With the slow-roll parameterηφ=-φ/(Hφ)being a constant,we calculate the power spectra for scalar and tensor per...We investigate the constant-roll inflation with non-minimally kinetic coupling to the Einstein tensor.With the slow-roll parameterηφ=-φ/(Hφ)being a constant,we calculate the power spectra for scalar and tensor perturbations,and derive the expressions for the scalar spectral tilt n_(s),the tensor spectral tilt n_(T),and the tensor-to-scalar ratio r.We find that the expressions for n_(s)are different with different ordering of taking the derivative of the scalar power spectrum with respect to the scale k and the horizon crossing condition c_(sk)=a H in the constant-roll inflation,the consistency relation r=-8n_(T)does not hold if|η_(φ)|is not small,and the duality of the tensorto-scalar ratio between the slow-roll inflation and ultra-slow-roll inflation does not exist in inflationary models with non-minimally derivative coupling.The result offers a fresh perspective on the understanding of the inflationary models with non-minimally derivative coupling and is helpful for the production of scalar induced gravitational waves in the framework of ultra-slowroll inflation with non-minimally derivative coupling.展开更多
We discuss the constant-roll inflation with constant ∈1 and constant η. By using the method of Bessel function approximation, the analytical expressions for the scalar and tensor power spectra, the scalar and tensor...We discuss the constant-roll inflation with constant ∈1 and constant η. By using the method of Bessel function approximation, the analytical expressions for the scalar and tensor power spectra, the scalar and tensor spectral tilts, and the tensor to scalar ratio are derived up to the first order of ∈1. The model with constant ∈2 is ruled out by the observations at the 3σ confidence level, and the model with constant η is consistent with the observations at the 1σ confidence level. The potential for the model with constant η is also obtained from the Hamilton-Jacobi equation. Although the observations constrain the constant-roll inflation to be the slow-roll inflation, the ns-r results from the constant-roll inflation are not the same as those from the slow-roll inflation even when η- 0.01.展开更多
基金supported by the Hainan Provincial Natural Science Foundation of China under Grant No.121MS033partially supported by the National Key Research and Development Program of China under Grant No.2020YFC2201504supported by the National Natural Science Foundation of China under Grant No.12205015。
文摘We investigate the constant-roll inflation with non-minimally kinetic coupling to the Einstein tensor.With the slow-roll parameterηφ=-φ/(Hφ)being a constant,we calculate the power spectra for scalar and tensor perturbations,and derive the expressions for the scalar spectral tilt n_(s),the tensor spectral tilt n_(T),and the tensor-to-scalar ratio r.We find that the expressions for n_(s)are different with different ordering of taking the derivative of the scalar power spectrum with respect to the scale k and the horizon crossing condition c_(sk)=a H in the constant-roll inflation,the consistency relation r=-8n_(T)does not hold if|η_(φ)|is not small,and the duality of the tensorto-scalar ratio between the slow-roll inflation and ultra-slow-roll inflation does not exist in inflationary models with non-minimally derivative coupling.The result offers a fresh perspective on the understanding of the inflationary models with non-minimally derivative coupling and is helpful for the production of scalar induced gravitational waves in the framework of ultra-slowroll inflation with non-minimally derivative coupling.
基金supported by the National Natural Science Foundation of China (Grant No. 11605061)the Fundamental Research Funds for the Central Universities (Grant Nos. XDJK2017C059, and SWU116053)
文摘We discuss the constant-roll inflation with constant ∈1 and constant η. By using the method of Bessel function approximation, the analytical expressions for the scalar and tensor power spectra, the scalar and tensor spectral tilts, and the tensor to scalar ratio are derived up to the first order of ∈1. The model with constant ∈2 is ruled out by the observations at the 3σ confidence level, and the model with constant η is consistent with the observations at the 1σ confidence level. The potential for the model with constant η is also obtained from the Hamilton-Jacobi equation. Although the observations constrain the constant-roll inflation to be the slow-roll inflation, the ns-r results from the constant-roll inflation are not the same as those from the slow-roll inflation even when η- 0.01.
