Isocurvature fluctuations induce early star formation

N. Sugiyama, S. Zaroubi, J. Silk

OnderzoeksoutputAcademicpeer review

7 Citaten (Scopus)
167 Downloads (Pure)


The early reionization of the Universe inferred from the WMAP polarization results, if confirmed, poses a problem for the hypothesis that scale-invariant adiabatic density fluctuations account for large-scale structure and galaxy formation. One can only generate the required amount of early star formation if extreme assumptions are made about the efficiency and nature of early reionization. We develop an alternative hypothesis that invokes an additional component of a non-scale-free isocurvature power spectrum together with the scale-free adiabatic power spectrum for inflation-motivated primordial density fluctuations. Such a component is constrained by the Lyman alpha forest observations, can account for the small-scale power required by spectroscopic gravitational lensing, and yields a source of early star formation that can reionize the Universe at z similar to 20 yet becomes an inefficient source of ionizing photons by z similar to 10, thereby allowing the conventional adiabatic fluctuation component to reproduce the late thermal history of the intergalactic medium.

Originele taal-2English
Pagina's (van-tot)543-548
Aantal pagina's6
TijdschriftMonthly Notices of the Royal Astronomical Society
Nummer van het tijdschrift2
StatusPublished - 21-okt.-2004

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