Coupling parsec and gigaparsec scales: Primordial non-Gaussianity with multitracer intensity mapping

Liu, Ruihan Henry; Breysse, Patrick C.

doi:10.1103/physrevd.103.063520

Cited by 28 publications

(25 citation statements)

References 77 publications

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“…In this Fisher analysis assuming the dataset {𝑃 CII (𝑘, 𝜇), 𝑃 CO(4→3) (𝑘, 𝜇), 𝑃 𝑥 }, we find 𝜎( 𝑓 𝑙𝑜𝑐 𝑁 𝐿 ) = 0.65, much lower than the initial experimental setup value for the [CII] auto power spectrum of 𝜎( 𝑓 𝑙𝑜𝑐 𝑁 𝐿 ) = 1.32. This result is expected since having multiple lines add more constraining power, and we benefit from the multi-tracer cosmic variance cancellation, as addressed in Liu & Breysse (2021).…”

Section: Cross-correlation With Other Linesmentioning

confidence: 70%

Removing Interlopers From Intensity Mapping Probes Of Primordial Non-Gaussianity

Chen,

Pullen

2021

Preprint

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Line intensity mapping (LIM) has the potential to produce highly precise measurements of scale-dependence bias from primordial non-Gaussianity (PNG) due to its ability to map much larger volumes than are available from galaxy surveys. PNG parameterized by 𝑓 𝑁 𝐿 leads to a scale-dependent correction to the bias, and therefore a correction to the line intensity power spectrum. However, LIM experiences contamination from foreground emission, including interloping emission lines from other redshifts which alter the power spectra of the maps at these scales, potentially biasing measurements of 𝑓 𝑁 𝐿 . Here we model the effect of line interlopers on upcoming line intensity mapping probes of primordial non-Gaussianity (PNG) from inflation. As an example, we consider the [CII] line at target redshift 𝑧 𝑡 = 3.6 to probe PNG, with the important systematic concern being foreground contamination from CO lines residing at redshifts different from the target redshift. We find interloper lines can lead to a significant bias and an increase in errors for our PNG constraints, leading to a false positive for non-standard inflation models. We model how well the cross-correlation technique could reduce this interloper contamination. We find the uncertainty of 𝑓 𝑁 𝐿 reduces by factors of two and six for local and orthogonal shape PNG respectively, and by a factor of five for local shape if we consider seven interloper lines, almost eliminating the effect of interlopers. This work shows that using cross-power and auto-power spectra of line intensity maps jointly could potentially remove the effects of interlopers when measuring non-Gaussianity.

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Section: Cross-correlation With Other Linesmentioning

confidence: 70%

Removing Interlopers From Intensity Mapping Probes Of Primordial Non-Gaussianity

Chen,

Pullen

2021

Preprint

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“…We discussed how this can be explained by the fact that these perturbations accelerate the conversion of hydrogen to heavier elements by star formation, and enhance the effects of feedback that ejects the gas out to regions where it is more easily ionized. We note that although the impact of astrophysical uncertainties on f nl constraints with line-intensity mapping data has been investigated in past works [14,16,17], this was done only through parametrizations of the gas-to-halo connection, i.e. M HI (M h ) for the case of H I .…”

Section: Discussionmentioning

confidence: 99%

“…This bound is still looser than the CMB one, but the volumes spanned by next-generation large-scale structure surveys should let us reach precisions of order σ fnl ∼ 1, which would mark, even without a detection, an important landmark in our ability to distinguish between competing models of inflation [7,8]. Some of these future constraints on f nl will come from studies of the spatial distribution of (atomic) neutral hydrogen (H I ) in the Universe [9][10][11][12][13][14][15][16][17][18][19], which will be mapped by 21cm line-intensity mapping experiments such as BINGO [20], CHIME [21], HIRAX [22] and SKA [23]. Compared to traditional galaxy surveying where individual galaxies are identified on the sky and their redshifts are estimated spectroscopically or photometrically, the line-intensity mapping approach targets the integrated emission from all sources (resolved or not) in a given region of the Universe, with the radial information inferred through measurements in different frequency bands [24].…”

mentioning

confidence: 99%

The local PNG bias of neutral Hydrogen, ${\rm H_I}$

Barreira

2021

Preprint

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We use separate universe simulations with the IllustrisTNG galaxy formation model to predict the local PNG bias parameters b φ and b φδ of atomic neutral hydrogen, H I . These parameters and their relation to the linear density bias parameter b 1 play a key role in observational constraints of the local PNG parameter f nl using the H I power spectrum and bispectrum. Our results show that the popular calculation based on the universality of the halo mass function overpredicts the b φ (b 1 ) and b φδ (b 1 ) relations measured in the simulations. In particular, our results show that at z 1 the H I power spectrum is more sensitive to f nl compared to previously thought (b φ is more negative), but is less sensitive at other epochs (b φ is less positive). We discuss how this can be explained by the competition of physical effects such as that large-scale gravitational potentials with local PNG (i) accelerate the conversion of hydrogen to heavy elements by star formation, (ii) enhance the effects of baryonic feedback that eject the gas to regions more exposed to ionizing radiation, and (iii) promote the formation of denser structures that shield the H I more efficiently. Our numerical results can be used to revise existing forecast studies on f nl using 21cm line-intensity mapping data. Despite this first step towards predictions for the local PNG bias parameters of H I , we emphasize that more work is needed to assess their sensitivity on the assumed galaxy formation physics and H I modeling strategy.

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“…Intensity mapping surveys may also be used to measure baryon acoustic oscillations (Chang et al, 2008), allowing for inference of the dark energy equation of state and cosmological parameters. Furthermore, they may also be used to measure signatures beyond the standard cosmological model, including primordial non-Gaussianity (Liu & Breysse, 2021) and signatures of dark matter annihilation (Bernal et al, 2021).…”

Section: Introductionmentioning

confidence: 99%

A Beginner’s Guide to Line Intensity Mapping Power Spectra

Oxholm

2022

Proc. Wisc. Space Conf.

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Line intensity mapping (LIM) is an emerging technique in measuring galaxy evolution and the large-scale structure of the universe. LIM surveys measure the cumulative emission from all galaxies emitting a given line at a particular redshift, which trace the distribution of dark matter throughout the universe. In this proceeding, we provide an introduction to LIM modeling, focusing on power spectrum calculation. Beyond these calculations, we describe how these power spectra may be used to constrain properties of galaxy evolution and large-scale structure cosmology. Throughout, we use the anticipated EXCLAIM signal of ionized carbon ([CII]) at redshift z=3 as a case study. Our goal is to provide a starting point to non-experts, e.g. upper-level undergraduate and graduate students familiar with the basics of cosmology, with the tools necessary to understand the literature and generate LIM power spectrum models themselves, while also describing a wide array of literature for continued studies.

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Coupling parsec and gigaparsec scales: Primordial non-Gaussianity with multitracer intensity mapping

Cited by 28 publications

References 77 publications

Removing Interlopers From Intensity Mapping Probes Of Primordial Non-Gaussianity

Removing Interlopers From Intensity Mapping Probes Of Primordial Non-Gaussianity

The local PNG bias of neutral Hydrogen, ${\rm H_I}$

A Beginner’s Guide to Line Intensity Mapping Power Spectra

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