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Other version: http://stacks.iop.org/0004637X/717/i=1/a=526?key=crossref.f16df570480d2dc73c972b145e861253
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Title 
The Halo Mass Function from Excursion Set Theory III. Non.Gaussian Fluctuations 

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Published in  Astrophysical Journal. 2010, vol. 717, no. 1, p. 526541  
Abstract  We compute the effect of primordial nonGaussianity on the halo mass function, using excursion set theory. In the presence of nonGaussianity, the stochastic evolution of the smoothed density field, as a function of the smoothing scale, is nonMarkovian and beside "local" terms that generalize PressSchechter (PS) theory, there are also "memory" terms, whose effect on the mass function can be computed using the formalism developed in the first paper of this series. We find that, when computing the effect of the threepoint correlator on the mass function, a PSlike approach which consists in neglecting the cloudincloud problem and in multiplying the final result by a fudge factor sime2, is in principle not justified. When computed correctly in the framework of excursion set theory, in fact, the "local" contribution vanishes (for all oddpoint correlators the contribution of the image Gaussian cancels the PS contribution rather than adding up), and the result comes entirely from nontrivial memory terms which are absent in PS theory. However it turns out that, in the limit of large halo masses, where the effect of nonGaussianity is more relevant, these memory terms give a contribution which is the same as that computed naively with PS theory, plus subleading terms depending on derivatives of the threepoint correlator. We finally combine these results with the diffusive barrier model developed in the second paper of this series, and we find that the resulting mass function reproduces recent Nbody simulations with nonGaussian initial conditions, without the introduction of any ad hoc parameter.  
Keywords  Cosmology: theory — Largescale structure of universe  
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Citation (ISO format)  MAGGIORE, Michele, RIOTTO, Antonio Walter. The Halo Mass Function from Excursion Set Theory III. Non.Gaussian Fluctuations. In: Astrophysical Journal, 2010, vol. 717, n° 1, p. 526541. https://archiveouverte.unige.ch/unige:35665 