Modelling the post-reionization neutral hydrogen (H i) 21-cm bispectrum

Sarkar, Debanjan; Majumdar, Suman; Bharadwaj, Somnath

doi:10.1093/mnras/stz2799

Cited by 19 publications

(10 citation statements)

References 119 publications

(96 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[21] found that upcoming 21-cm surveys could be able to measure the FDM particle mass as high as 10 −18 eV, which would be interesting to revisit under the inclusion of additional heating effects. The higher order statistics, like the bispectrum [88][89][90][91], trispectrum [92] etc., if measured with high accuracy, will provide us with more constraining power. We leave these for future study.…”

Section: Discussionmentioning

confidence: 99%

Exploring delaying and heating effects on the 21-cm signature of fuzzy dark matter

Sarkar,

Flitter,

Kovetz

2022

Preprint

Self Cite

View full text Add to dashboard Cite

In the fuzzy dark matter (FDM) model, dark matter is composed of ultra-light particles with a de Broglie wavelength of ∼kpc, above which it behaves like cold dark matter (CDM). Due to this, FDM suppresses the growth of structure on small scales, which delays the onset of the cosmic dawn (CD) and the subsequent epoch of reionization (EoR). This leaves potential signatures in the sky averaged 21-cm signal (global), as well as in the 21-cm fluctuations, which can be sought for with ongoing and future 21-cm global and intensity mapping experiments. To do so reliably, it is crucial to include effects such as the dark-matter/baryon relative velocity and Lyman-Werner star-formation feedback, which also act as delaying mechanisms, as well as CMB and Lyman-α heating effects, which can significantly change the amplitude and timing of the signal, depending on the strength of X-ray heating sourced by the remnants of the first stars. Here we model the 21-cm signal in FDM cosmologies across CD and EoR using a modified version of the public code 21cmvFAST that accounts for all these additional effects, and is directly interfaced with the Boltzmann code CLASS so that degeneracies between cosmological and astrophysical parameters can be fully explored. We examine the prospects to distinguish between the CDM and FDM models and forecast joint astrophysical, cosmological and FDM parameter constraints achievable with intensity mapping experiments such as HERA and global signal experiments like EDGES. We find that HERA will be able to detect FDM particle masses up to mFDM ∼ 10 −19 eV − 10 −18 eV, depending on foreground assumptions, despite the mitigating effect of the delaying and heating mechanisms included in the analysis.

show abstract

Section: Discussionmentioning

confidence: 99%

Exploring delaying and heating effects on the 21-cm signature of fuzzy dark matter

Sarkar,

Flitter,

Kovetz

2022

Preprint

Self Cite

View full text Add to dashboard Cite

show abstract

“…[62]. Other possible strategies include the combination with other cosmological probes [56] or joint analyses of two-point and higher order statistics measurements [80,81].…”

Section: Discussionmentioning

confidence: 99%

“…[80] in the case of halo number counts, and Ref. [81] for the 21cm LIM case); multi-tracer techniques with several spectral lines and galaxy surveys [56]; or the exploitation of the mildly non-linear regime of the LIM power spectrum by modelling the halo clustering with Lagrangian perturbation theory [62].…”

Section: Explicitly Accounting For the Degeneraciesmentioning

confidence: 99%

User’s guide to extracting cosmological information from line-intensity maps

et al. 2019

View full text Add to dashboard Cite

Line-intensity mapping (LIM) provides a promising way to probe cosmology, reionization and galaxy evolution. However, its sensitivity to cosmology and astrophysics at the same time is also a nuisance. Here we develop a comprehensive framework for modelling the LIM power spectrum, which includes redshift space distortions and the Alcock-Paczynski effect. We then identify and isolate degeneracies with astrophysics so that they can be marginalized over. We study the gains of using the multipole expansion of the anisotropic power spectrum, providing an accurate analytic expression for their covariance, and find a 10%-60% increase in the precision of the baryon acoustic oscillation scale measurements when including the hexadecapole in the analysis. We discuss different observational strategies when targeting other cosmological parameters, such as the sum of neutrino masses or primordial non-Gaussianity, finding that fewer and wider bins are typically more optimal. Overall, our formalism facilitates an optimal extraction of cosmological constraints robust to astrophysics.PACS numbers:

show abstract

“…Unlike the power spectrum, the bispectrum is sensitive to the shape of the structures generated by gravitational instability and has the promise to break important degeneracies in the bias and cosmological parameters (Scoccimarro 2000;Sefusatti et al 2006;Hahn et al 2020;Yankelevich & Porciani 2019;Chudaykin & Ivanov 2019). The post-reionization 21cm signal is expected to have significant information in the non-linear regime and there have been recent attempts at theoretical modeling of the Hi bispectrum (Sarkar et al 2019). One of the toughest parts in a bispectrum analysis is calculation of the error due to cosmic variance and a fast technique to generate mock Hi fields is therefore essential.…”

Section: Cross-correlation With Galaxies and Halosmentioning

confidence: 99%

HInet: Generating neutral hydrogen from dark matter with neural networks

Wadekar,

Villaescusa-Navarro,

et al. 2020

Preprint

View full text Add to dashboard Cite

Upcoming 21cm surveys will map the spatial distribution of cosmic neutral hydrogen (HI) over very large cosmological volumes. In order to maximize the scientific return of these surveys, accurate theoretical predictions are needed. Hydrodynamic simulations currently are the most accurate tool to provide those predictions in the mildly to non-linear regime. Unfortunately, their computational cost is very high: tens of millions of CPU hours. We use convolutional neural networks to find the mapping between the spatial distribution of matter from N-body simulations and HI from the state-of-the-art hydrodynamic simulation IllustrisTNG. Our model performs better than the widely used theoretical model: Halo Occupation Distribution (HOD) for all statistical properties up to the non-linear scales k 1 h/Mpc. Our method allows the generation of 21cm mocks over very big cosmological volumes with similar properties as hydrodynamic simulations.

show abstract

Modelling the post-reionization neutral hydrogen (H i) 21-cm bispectrum

Cited by 19 publications

References 119 publications

Exploring delaying and heating effects on the 21-cm signature of fuzzy dark matter

Exploring delaying and heating effects on the 21-cm signature of fuzzy dark matter

User’s guide to extracting cosmological information from line-intensity maps

HInet: Generating neutral hydrogen from dark matter with neural networks

Contact Info

Product

Resources

About