Numerical calculation of hubble hierarchy parameters and observational parameters of inflation

Abstract

We present results obtained by a software we developed for computing observational cosmological inflation parameters: the scalar spectral index (n s ) and the tensor-to-scalar ratio (r) for a standard single field and tachyon inflation, as well as for a tachyon inflation in the second Randall-Sundrum model with an additional radion field. The calculated numerical values of observational parameters are compared with the latest results of observations obtained by the Planck Collaboration. The program is written in C/C++. The GNU Scientific Library is used for some of the numerical computations and R language is used for data analysis and plots. * mmilan@seenet-mtp.info arXiv:1809.04939v1 [gr-qc]

Constant-roll inflation with tachyon field in the holographic braneworld

“…For this choice of the parameters, using expressions (66) and (67), we find η = 0.0817 and h ,θi = −0.4495. It is obvious from figure 3 that the reconstructed potential has all properties of a tachyon potential, defined by (16).…”

“…Note that previous results for the number of e-folds were obtained using the functional relationship between the observational parameters and the initial conditions h i and h ,θi , equations (66) and (67). More accurate results can be obtained using (60) and (61) and applying the standard approach based on calculating observation parameters n s and r for a given e-folds number N, described in details in [15,16,18]. For randomly chosen η, h i , the equation ( 26) and the differential equation for number of e-folds dN/dθ = h/(ℓ θ), are from θ i = 0 arbitrary value θ f which is large provide the end of inflation (ε 1 (θ f ) = 1).…”

“…This formalism has been applied in many different scenarios of inflation [5][6][7][8][9][10][11][12][13][14]. In this work, for the first time, we apply the formalism of the constant-roll inflation to the holographic second Randall-Sundrum (RSII) model with a tachyon field [15,16]. This paper is an extension of our previous work in which we studied the constant-roll tachyon inflation in the RSII cosmology [17].…”