Inflationary predictions for scalar and tensor fluctuations reconsidered
Abstract
We reconsider the predictions of inflation for the spectral index of scalar (energy density) fluctuations (n_s) and the tensor/scalar ratio (r) using a discrete, model-independent measure of the degree of fine-tuning required to obtain a given combination of (n_s, r). We find that, except for cases with numerous unnecessary degrees of fine-tuning, n_s is less than 0.98, measurably different from exact Harrison-Zel'dovich. Furthermore, if n_s \gtrsim 0.95, in accord with current measurements, the tensor/scalar ratio satisfies r \gtrsim 10^{-2}, a range that should be detectable in proposed cosmic microwave background polarization experiments and direct gravitational wave searches.
Cite
@article{arxiv.astro-ph/0507455,
title = {Inflationary predictions for scalar and tensor fluctuations reconsidered},
author = {Latham A. Boyle and Paul J. Steinhardt and Neil Turok},
journal= {arXiv preprint arXiv:astro-ph/0507455},
year = {2009}
}
Comments
4 pages, 2 figures; references updated; version accepted for publication in PRL