Measuring the growth of structure with intensity mapping surveys. (arXiv:1902.07147v1 [astro-ph.CO])
<a href="http://arxiv.org/find/astro-ph/1/au:+Castorina_E/0/1/0/all/0/1">Emanuele Castorina</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+White_M/0/1/0/all/0/1">Martin White</a>
Line intensity mapping offers a new avenue for constraining cosmological
parameters in the high redshift Universe. However measurements of the growth of
structure, a sensitive probe of gravity, are affected by a well known
degeneracy with astrophysical parameters, encoded in the mean brightness
temperature of the specific line. In this work we show how to break this
degeneracy, to a level that could allow constraints of the amplitude of
cosmological fluctuations at the percent level, using information in the mildly
non-linear regime of structure formation as described by Lagrangian
Perturbation Theory. We focus on the 21-cm line with forecasts for HIRAX and
the proposed Stage II experiment as illustrations.
Line intensity mapping offers a new avenue for constraining cosmological
parameters in the high redshift Universe. However measurements of the growth of
structure, a sensitive probe of gravity, are affected by a well known
degeneracy with astrophysical parameters, encoded in the mean brightness
temperature of the specific line. In this work we show how to break this
degeneracy, to a level that could allow constraints of the amplitude of
cosmological fluctuations at the percent level, using information in the mildly
non-linear regime of structure formation as described by Lagrangian
Perturbation Theory. We focus on the 21-cm line with forecasts for HIRAX and
the proposed Stage II experiment as illustrations.
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