Astronomy and Astrophysics – Astrophysics
Scientific paper
1996-11-13
Phys.Rev. D55 (1997) 7423-7439
Astronomy and Astrophysics
Astrophysics
21 pages, RevTex. 12 figures
Scientific paper
10.1103/PhysRevD.55.7423
We explore the role of non-Gaussian fluctuations in primordial black hole (PBH) formation and show that the standard Gaussian assumption, used in all PBH formation papers to date, is not justified. Since large spikes in power are usually associated with flat regions of the inflaton potential, quantum fluctuations become more important in the field dynamics, leading to mode-mode coupling and non-Gaussian statistics. Moreover, PBH production requires several sigma (rare) fluctuations in order to prevent premature matter dominance of the universe, so we are necessarily concerned with distribution tails, where any intrinsic skewness will be especially important. We quantify this argument by using the stochastic slow-roll equation and a relatively simple analytic method to obtain the final distribution of fluctuations. We work out several examples with toy models that produce PBH's, and show that the naive Gaussian assumption can result in errors of many orders of magnitude. For models with spikes in power, our calculations give sharp cut-offs in the probability of large positive fluctuations, meaning that Gaussian distributions would vastly over-produce PBH's. The standard results that link inflation-produced power spectra and PBH number densities must then be reconsidered, since they rely quite heavily on the Gaussian assumption. We point out that since the probability distributions depend on the nature of the potential, it is impossible to obtain results for general models. However, calculating the distribution of fluctuations for any specific model seems to be relatively straightforward, at least in the single inflaton case.
Bullock James S.
Primack Joel R.
No associations
LandOfFree
Non-Gaussian Fluctuations and Primordial Black Holes from Inflation does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Non-Gaussian Fluctuations and Primordial Black Holes from Inflation, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Non-Gaussian Fluctuations and Primordial Black Holes from Inflation will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-604901