An Isocurvature Model for Early Galaxy Assembly

摘要

The evidence for early assembly of the central parts of the giant galaxies is a challenge for the adiabatic cold dark matter (CDM) model for structure formation; it more readily fits an isocurvature version where homogeneity is broken by CDM that is the remnant of a massive scalar field frozen from quantum fluctuations during inflation. In this picture the primeval CDM mass distribution is proportional to the square of a random Gaussian process, so for a given power spectrum the prominent upward density fluctuations have contrast about three times that of a Gaussian process.