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Baryon Acoustic Oscillation Intensity Mapping of Dark Energy
TLDR
Here it is shown how the study of acoustic oscillation in the 21 cm brightness can be accomplished by economical three-dimensional intensity mapping, and may be the starting point for a new class of dark energy experiments dedicated to large angular scale mapping of the radio sky, shedding light on dark energy.Abstract:
The expansion of the universe appears to be accelerating, and the mysterious anti-gravity agent of this acceleration has been called ``dark energy''. To measure the dynamics of dark energy, Baryon Acoustic Oscillations (BAO) can be used. Previous discussions of the BAO dark energy test have focused on direct measurements of redshifts of as many as $10^9$ individual galaxies, by observing the 21cm line or by detecting optical emission. Here we show how the study of acoustic oscillation in the 21 cm brightness can be accomplished by economical three dimensional intensity mapping. If our estimates gain acceptance they may be the starting point for a new class of dark energy experiments dedicated to large angular scale mapping of the radio sky, shedding light on dark energy.read more
Citations
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Observational probes of cosmic acceleration
David H. Weinberg,Michael J. Mortonson,Daniel J. Eisenstein,Daniel J. Eisenstein,Christopher M. Hirata,Adam G. Riess,Eduardo Rozo +6 more
TL;DR: In this article, the authors present extensive forecasts for constraints on the dark energy equation of state and parameterized deviations from General Relativity, achievable with Stage III and Stage IV experimental programs that incorporate supernovae, BAO, weak lensing, and cosmic microwave background data.
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21 cm cosmology in the 21st century
TL;DR: This review detail the physics that governs the 21 cm signal and describe what might be learnt from upcoming observations, and generalize the discussion to intensity mapping of other atomic and molecular lines.
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Reionization and Cosmology with 21-cm Fluctuations
TL;DR: In this article, the authors discuss recent advances in theoretical understanding of the epoch of reionization (EoR), the application of 21-cm tomography to cosmology and measurements of the dark energy equation of state after reionisation, and the instrumentation and observational techniques shared by 21cm EoR and postreionization cosmology machines.
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Clustering of dark matter tracers: generalizing bias for the coming era of precision LSS
Patrick J. McDonald,A. Roy +1 more
TL;DR: In this paper, the power spectrum and bispectrum up to 4th order in the initial density perturbations were modeled as a Taylor series in the local mass density, with the unknown coefficients in the series treated as free bias parameters.
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Late-time cosmology with 21cm intensity mapping experiments
TL;DR: In this paper, the authors present a framework for forecasting cosmological constraints from future neutral hydrogen intensity mapping experiments at low to intermediate redshifts, and establish a simple way of comparing such surveys with optical galaxy redshift surveys.
References
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Journal ArticleDOI
The effect of foreground subtraction on cosmological measurements from intensity mapping
TL;DR: In this paper, the authors present the power spectrum of the large-scale matter distribution, C(l), before and after the application of this foreground removal method and calculate the systematic errors.
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Linear growth of structure in massive bigravity
TL;DR: In this paper, the ghost-free theory of massive gravity with two dynamical metrics has been shown to produce viable cosmological expansion, where the late-time acceleration of the Universe is due to the finite range of the gravitational interaction rather than a nonzero cosmology constant.
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The Baryon Acoustic Oscillation Broadband and Broad-beam Array: Design Overview and Sensitivity Forecasts
Jonathan C. Pober,Aaron R. Parsons,David DeBoer,Patrick McDonald,Matthew McQuinn,James E. Aguirre,Zaki S. Ali,Richard F. Bradley,Richard F. Bradley,Tzu-Ching Chang,Miguel F. Morales +10 more
TL;DR: The Baryon Acoustic Oscillation Broadband and Broad-beam (BAOBAB) Array as discussed by the authors was designed for the detection of the neutral hydrogen 21cm power spectrum between redshifts of 0.5-1.5.
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Gravitational redshift and other redshift-space distortions of the imaginary part of the power spectrum
TL;DR: In this article, the authors extend the usual linear-theory formula for large-scale clustering in redshift-space to include gravitational redshift, and show that a correlation is generated between the real and imaginary parts of the Fourier space density fields of two different types of galaxies, which would otherwise be zero.
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Modeling the neutral hydrogen distribution in the post-reionization Universe: intensity mapping
Abstract: We model the distribution of neutral hydrogen (HI) in the post-reionization era and investigate its detectability in 21 cm intensity mapping with future radio telescopes like the Square Kilometer array (SKA). We rely on high resolution hydrodynamical N-body simulations that have a state-of-the-art treatment of the low density photoionized gas in the inter-galactic medium (IGM). The HI is assigned a-posteriori to the gas particles following two different approaches: a halo-based method in which HI is assigned only to gas particles residing within dark matter halos; a particle-based method that assigns HI to all gas particles using a prescription based on the physical properties of the particles. The HI statistical properties are then compared to the observational properties of Damped Lyman-α Absorbers (DLAs) and of lower column density systems and reasonable good agreement is found for all the cases. Among the halo-based method, we further consider two different schemes that aim at reproducing the observed properties of DLAs by distributing HI inside halos: one of this results in a much higher bias for DLAs, in agreement with recent observations, which boosts the 21 cm power spectrum by a factor ~ 4 with respect to the other recipe. Furthermore, we quantify the contribution of HI in the diffuse IGM to both ΩHI and the HI power spectrum finding to be subdominant in both cases. We compute the 21 cm power spectrum from the simulated HI distribution and calculate the expected signal for both SKA1-mid and SKA1-low configurations at 2.4 ≤ z ≤ 4. We find that SKA will be able to detect the 21 cm power spectrum, in the non-linear regime, up to k ~ 1 h/Mpc for SKA1-mid and k ~ 5 h/Mpc for SKA1-low with 100 hours of observations. We also investigate the perspective of imaging the HI distribution. Our findings indicate that SKA1-low could detect the most massive HI peaks with a signal to noise ratio (SNR) higher than 5 for an observation time of about 1000 hours at z = 4, for a synthesized beam width of 2'. Detection at redshifts z≥2.4 with SKA1-mid would instead require a much longer observation time to achieve a comparable SNR level.