Cutoff in the Lyman α forest power spectrum: warm IGM or warm dark matter?

Antonella Garzilli, Alexey Boyarsky, Oleg Ruchayskiy

Published 2015-10-23Version 1

We re-analyse high redshift and high resolution Lyman-{\alpha} forest spectra from Viel et al. [1] seeking to constrain properties of warm dark matter particles. Compared to the previous work we consider a wider range on thermal histories of the intergalactic medium and find that both warm and cold dark matter models can explain the cut-off observed in the flux power spectra of high-resolution observations equally well. This implies, however, very different thermal histories and underlying re-ionisation models. We discuss how to remove this degeneracy.