3,167 research outputs found
Passive Curvaton
We propose a class of curvaton models which we call passive curvaton. In this
paper, two kinds of passive curvaton is considered. The first one is a
pseudoscalar curvaton couples to a gauge field. Different from the inflaton
case, the constraint from formation of primordial black holes (PBHs) is much
weaker and large non-gaussianity (of the equiliteral type) can be produced. The
second model is a dilaton-like scalar curvaton couples to a gauge field. We
investigate the scale dependence of non-gaussianity in this model. In both
models, the spectrum and non-Gaussianity are enhanced by the slow-roll
parameter of the curvaton field. Other possible passive curvaton models are
also mentioned.Comment: 9 pages, 2 figures, to appear in PL
Primordial Black Holes from Passive Density Fluctuations
In this paper, we show that if passive fluctuations are considered,
primordial black holes (PBHs) can be easily produced in the framework of
single-field, slow-roll inflation models. The formation of PBHs is due to the
blue spectrum of passive fluctuations and an enhancement of the spectral range
which exits horizon near the end of inflation. Therefore the PBHs are light
with masses depending on the number of e-folds when the
scale of our observable universe leaves horizon. These PBHs are likely to have
evaporated and cannot be a candidate for dark matter but they may still affect
the early universe.Comment: 7 pages, 1 figure, to appear in Physics Letters
- …