Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Baryon acoustic oscillations from HI intensity mapping: the importance
  of cross-correlations in the monopole and quadrupole   Cosmological parameter estimation in the post-reionisation era via the radio
emission of neutral hydrogen (HI), is one of the key science goals of the
forthcoming SKA Observatory (SKAO). In this paper, we explore detection
capability for baryon acoustic oscillations (BAO) with a SKAO-like experimental
set up, using a suite of 100 simulations inclusive of the main limitations from
foreground contamination and poor angular resolution caused by the radio
telescope beam. The latter represents a serious challenge for BAO detection
with HI intensity mapping, hence we investigate adopting a multipole expansion
approach as a means for mitigating the BAO detection limitations caused by the
broad single-dish beam. We also showcase the gains made from cross-correlating
the HI intensity mapping data with an overlapping spectroscopic galaxy survey,
aiming to test the potential synergies between the SKA Project and other future
cosmological experiments at optical/near-infrared wavelengths, like the Euclid
satellite or the Dark Energy Spectroscopic Instrument. Whilst we were still
able to achieve a ~4.5 sigma detection of BAO features in auto-correlation
despite the dominant beam effect, a cross-correlation can increase this to a ~6
sigma detection. Furthermore, by adopting the widely studied multipole
expansion formalism, we show that including the power spectrum quadrupole
besides the monopole in a joint fit can approximately double the BAO detection
significance. Despite not implementing a radial-only power spectrum analysis in
favour of the three-dimensional power spectrum and its multipoles, we were
still able to obtain robust constraints on the radial Alcock-Paczynski
parameter, but found that perpendicular parameter remains unconstrained and
prior dominated due to beam effects.

25
The categories of this paper are: patt-sol
17
The categories of this paper are: q-fin
23
The categories of this paper are: solv-int
32
The categories of this paper are: atom-ph
15
The categories of this paper are: nucl-ex
0
The categories of this paper are: hep-ph
31
The categories of this paper are: ao-sci
30
The categories of this paper are: q-alg
10
The categories of this paper are: q-bio
22
The categories of this paper are: chao-dyn
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The categories of this paper are: comp-gas
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The categories of this paper are: bayes-an
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The categories of this paper are: eess
8
The categories of this paper are: hep-ex
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The categories of this paper are: funct-an
12
The categories of this paper are: nucl-th