Testing Large-Scale Structure Measurements Against Fisher Matrix Predictions. (arXiv:2106.11432v2 [astro-ph.CO] UPDATED)
<a href="http://arxiv.org/find/astro-ph/1/au:+Foroozan_S/0/1/0/all/0/1">Setareh Foroozan</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Krolewski_A/0/1/0/all/0/1">Alex Krolewski</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Percival_W/0/1/0/all/0/1">Will J. Percival</a>
We compare Baryonic Acoustic Oscillation (BAO) and Redshift Space Distortion
(RSD) measurements from recent galaxy surveys with their Fisher matrix based
predictions. Measurements of the position of the BAO signal lead to constraints
on the comoving angular diameter distance $D_{M}$ and the Hubble distance
$D_{H}$ that agree well with their Fisher matrix based expectations. However,
RSD-based measurements of the growth rate $f sigma_{8}$ do not agree with the
predictions made before the surveys were undertaken, even when repeating those
predictions using the actual survey parameters. We show that this is due to a
combination of effects including degeneracies with the geometric parameters
$D_{M}$ and $D_{H}$, and optimistic assumptions about the scale to which the
linear signal can be extracted. We show that measurements using current data
and large-scale modelling techniques extract an equivalent amount of signal to
that in the linear regime for $k < 0.08 ,h,{rm Mpc}^{-1}$, remarkably
independent of the sample properties and redshifts covered.
We compare Baryonic Acoustic Oscillation (BAO) and Redshift Space Distortion
(RSD) measurements from recent galaxy surveys with their Fisher matrix based
predictions. Measurements of the position of the BAO signal lead to constraints
on the comoving angular diameter distance $D_{M}$ and the Hubble distance
$D_{H}$ that agree well with their Fisher matrix based expectations. However,
RSD-based measurements of the growth rate $f sigma_{8}$ do not agree with the
predictions made before the surveys were undertaken, even when repeating those
predictions using the actual survey parameters. We show that this is due to a
combination of effects including degeneracies with the geometric parameters
$D_{M}$ and $D_{H}$, and optimistic assumptions about the scale to which the
linear signal can be extracted. We show that measurements using current data
and large-scale modelling techniques extract an equivalent amount of signal to
that in the linear regime for $k < 0.08 ,h,{rm Mpc}^{-1}$, remarkably
independent of the sample properties and redshifts covered.
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