Beschreibung:
<jats:title>Abstract</jats:title>
<jats:p>We present an effective model for the one-dimensional
Lyman-α flux power spectrum far above the baryonic Jeans
scale. The main new ingredient is constituted by a set of two
parameters that encode the impact of small, highly non-linear scales
on the one-dimensional power spectrum on large scales, where it is
measured by BOSS. We show that, by marginalizing over the model
parameters that capture the impact of the intergalactic medium, the
flux power spectrum from both simulations and observations can be
described with high precision. The model displays a degeneracy
between the neutrino masses and the (unknown, in our formalism)
normalization of the flux power spectrum. This degeneracy can be
lifted by calibrating one of the model parameters with simulation
data, and using input from Planck CMB data. We demonstrate that this
approach can be used to extract bounds on the sum of neutrino masses
with comparably low numerical effort, while allowing for a
conservative treatment of uncertainties from the dynamics of the
intergalactic medium. An explorative analysis yields an upper bound
of 0.16eV at 95% C.L. when applied to BOSS data at
3 ≤ z ≤ 4.2. We also forecast that if the systematic and
statistical errors will be reduced by a factor two the upper bound
will become 0.1eV at 95% C.L, and 0.056eV when assuming a
1% error. </jats:p>