1108.4203 (Diego Chialva)

Signatures of very high energy physics in the squeezed limit of the bispectrum from the field theoretical approach    [PDF]

Diego Chialva

We investigate the signatures, in the squeezing limit of the primordial scalar bispectrum, of modifications of the standard theory at high energy, such as a modified quantum vacuum or modified dispersion relations, reflecting the effects of different physics at higher energies/earlier times. Our results are obtained through the analysis in field theory and not using the (approximated) templates for the bispectrum. In this way we can obtain the precise dependence on the probed scale and quantify the presence of enhancements and/or non-local shape of the non-Gaussianities, which are relevant, for example, for measurements of the halo bias. It is shown that the signatures are distinctive and can be determined in general, and the results are different from those obtained using the templates proposed in the literature, where existing, in particular because of the interplay between the scale of the observations and the scale of the high-energy physics when taking the large-scale (squeezed) limit. Several pieces of information regarding high energy physics could be obtained in case of detection of these signals, especially bounds on the scales of new physics.

View original: http://arxiv.org/abs/1108.4203