Non-standard structure formation scenarios |
| |
| Authors: | Alexander Knebe Brett Little Ranty Islam Julien Devriendt Asim Mahmood Joe Silk |
| |
| Institution: | (1) Centre for Astrophysics & Supercomputing, Swinburne University, Australia;(2) Australian National University, Australia;(3) Denys Wilkinson Building, Keble Road, Oxford, OX1 3RH, UK |
| |
| Abstract: | Observations on galactic scales seem to be in contradiction with recent high resolution N-body simulations. This so-called cold dark matter (CDM) crisis has been addressed in several ways, ranging from a change
in fundamental physics by introducing self-interacting cold dark matter particles to a tuning of complex astrophysical processes
such as global and/or local feedback. All these efforts attempt to soften density profiles and reduce the abundance of satellites
in simulated galaxy halos. In this contribution we are exploring the differences between a Warm Dark Matter model and a CDM
model where the power on a certain scale is reduced by introducing a narrow negative feature (`dip'). This dip is placed in
a way so as to mimic the loss of power in the WDM model: both models have the same integrated power out to the scale where
the power of the Dip model rises to the level of the unperturbed CDM spectrum again. Using N-body simulations we show that that the new Dip model appears to be a viable alternative to WDM while being based on different
physics: where WDM requires the introduction of a new particle species the Dip stems from anon-standard inflationary period.
If we are looking for an alternative to the currently challenged standard ΛCDM structure formation scenario, neither the ΛWDM
nor the new Dip model can be ruled out with respect to the analysis presented in this contribution. They both make very similar
predictions and the degeneracy between them can only be broken with observations yet to come.
This revised version was published online in August 2006 with corrections to the Cover Date. |
| |
| Keywords: | cosmology: theory cosmology: large scale structure of Universe |
| 本文献已被 SpringerLink 等数据库收录！ |
|
