Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8141808 | Physics of the Dark Universe | 2018 | 7 Pages |
Abstract
To understand the formation and evolution of galaxies at redshifts 0â²zâ²10, one must invariably introduce specific models (e.g., for the star formation) in order to fully interpret the data. Unfortunately, this tends to render the analysis compliant to the theory and its assumptions, so consensus is still somewhat elusive. Nonetheless, the surprisingly early appearance of massive galaxies challenges the standard model, and the halo mass function estimated from galaxy surveys at zâ³4 appears to be inconsistent with the predictions of ÎCDM, giving rise to what has been termed “The Impossibly Early Galaxy Problem” by some workers in the field. A simple resolution to this question may not be forthcoming. The situation with the halos themselves, however, is more straightforward and, in this paper, we use linear perturbation theory to derive the halo mass function over the redshift range 0â²zâ²10 for the Rh=ct universe. We use this predicted halo distribution to demonstrate that both its dependence on mass and its very weak dependence on redshift are compatible with the data. The difficulties with ÎCDM may eventually be overcome with refinements to the underlying theory of star formation and galaxy evolution within the halos. For now, however, we demonstrate that the unexpected early formation of structure may also simply be due to an incorrect choice of the cosmology, rather than to yet unknown astrophysical issues associated with the condensation of mass fluctuations and subsequent galaxy formation.
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Astronomy and Astrophysics
Authors
Manoj K. Yennapureddy, Fulvio Melia,