Number counts and nonGaussianity
Abstract
We describe a general procedure for using number counts of any object to constrain the probability distribution of the primordial fluctuations, allowing for generic weak nonGaussianity. We apply this procedure to use limits on the abundance of primordial black holes and dark matter ultracompact minihalos to characterize the allowed statistics of primordial fluctuations on very small scales. We present constraints on the power spectrum and the amplitude of the skewness for two different families of nonGaussian distributions, distinguished by the relative importance of higher moments. Although primordial black holes probe the smallest scales, ultracompact minihalos provide significantly stronger constraints on the power spectrum and so are more likely to eventually provide smallscale constraints on nonGaussianity.
 Publication:

Physical Review D
 Pub Date:
 November 2013
 DOI:
 10.1103/PhysRevD.88.103506
 arXiv:
 arXiv:1211.7361
 Bibcode:
 2013PhRvD..88j3506S
 Keywords:

 98.80.Cq;
 95.35.+d;
 98.80.k;
 Particletheory and fieldtheory models of the early Universe;
 Dark matter;
 Cosmology;
 Astrophysics  Cosmology and Extragalactic Astrophysics;
 General Relativity and Quantum Cosmology;
 High Energy Physics  Phenomenology
 EPrint:
 19 pages