Monday, February 6, 2012

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

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