CMB Fluctuations and String Compactification Scales
Abstract
We propose a mechanism for the generation of temperature fluctuations of cosmic microwave background. We consider a large number of fields, such as Kaluza-Klein modes and string excitations. Each field contributes to the gravitational potential by a small amount, but an observable level of temperature fluctuations is achieved by summing up the contribution of typically of order 10^{14} fields. Tensor fluctuations are hardly affected by these fields. Our mechanism is based on purely quantum effects, and is different from the "slow-roll" or "curvaton" scenario. Using the observed data, we find constraints on the parameters of this model, such as the size of the extra dimensions and the string scale. Our model predicts a particular pattern of non-gaussianity with a small magnitude.
Cite
@article{arxiv.1103.0299,
title = {CMB Fluctuations and String Compactification Scales},
author = {Yoshinobu Habara and Hikaru Kawai and Masao Ninomiya and Yasuhiro Sekino},
journal= {arXiv preprint arXiv:1103.0299},
year = {2015}
}
Comments
4 pages, 2 figures; v2: Corrected a mistake in eq. (11), which does not affect the subsequent context. Added a comment on inflaton fluctuations at the end of the paper. Final version to appear in Phys. Lett. B