Radio-optical synergies at high redshift to constrain primordial non-Gaussianity

Abstract

We apply the multi-tracer technique to test the possibility of improved constraints on the amplitude of local primordial non-Gaussianity, $f_{\mathrm{NL}}$, in the cosmic large-scale structure. A precise measurement of $f_{\mathrm{NL}}$ is difficult because the effects of non-Gaussianity mostly arise on the largest scales, which are heavily affected by the low statistical sampling commonly referred to as cosmic variance. The multi-tracer approach suppresses cosmic variance and we implement it by combining the information from next-generation galaxy surveys in the optical/near-infrared band and neutral hydrogen (HI) intensity mapping surveys in the radio band. High-redshift surveys enhance the precision on $f_{\mathrm{NL}}$, due to the larger available volume, and HI intensity mapping surveys can naturally reach high redshifts. In order to extend the redshift coverage of a galaxy survey, we consider different emission-line galaxy populations, focusing on the H$\alpha$ line at low redshift and on oxygen lines at higher redshift. By doing so, we cover a wide redshift range $1\lesssim z\lesssim 4$. To assess the capability of our approach, we implement a synthetic-data analysis by means of Markov chain Monte Carlo sampling of the (cosmological+nuisance) parameter posterior, to evaluate the constraints on $f_{\mathrm{NL}}$ obtained in different survey configurations. We find significant improvements from the multi-tracer technique: the full data set leads to a precision of $\sigma (f_{\mathrm{NL}})<1$.

30 pages, 12 figures, 2 tables; accepted for publication on JCAP

References in corpus (33)

• The imprints of primordial non-gaussianities on large-scale structure: scale dependent bias and abundance of virialized objects
• Measuring primordial non-gaussianity without cosmic variance
• Late-time cosmology with 21cm intensity mapping experiments
• Primordial non-Gaussianity: large-scale structure signature in the perturbative bias model
• The High Latitude Spectroscopic Survey on the Nancy Grace Roman Space Telescope
• Evolution of the H$\beta$+[OIII] and [OII] luminosity functions and the [OII] star-formation history of the Universe up to $z$ ~ 5 from HiZELS
• HI intensity mapping with MeerKAT: power spectrum detection in cross-correlation with WiggleZ galaxies
• Einstein's legacy in galaxy surveys
• Inflation: Theory and Observations
• Primordial Non-Gaussianity from Biased Tracers: Likelihood Analysis of Real-Space Power Spectrum and Bispectrum
• SKAO HI Intensity Mapping: Blind Foreground Subtraction Challenge
• 21cm foregrounds and polarization leakage: a user's guide on cleaning and mitigation strategies
• Can we actually constrain $f_{\mathrm{NL}}$ using the scale-dependent bias effect? An illustration of the impact of galaxy bias uncertainties using the BOSS DR12 galaxy power spectrum
• On the impact of galaxy bias uncertainties on primordial non-Gaussianity constraints
• Galaxy bias and primordial non-Gaussianity: insights from galaxy formation simulations with IllustrisTNG
• Recovery of 21 cm intensity maps with sparse component separation
• Euclid preparation: XIX. Impact of magnification on photometric galaxy clustering
• Impact of Foregrounds on HI Intensity Mapping Cross-Correlations with Optical Surveys
• Predictions for local PNG bias in the galaxy power spectrum and bispectrum and the consequences for $f_{\mathrm{NL}}$ constraints
• Assembly bias in the local PNG halo bias and its implication for $f_{\mathrm{NL}}$ constraints
• The foreground transfer function for HI intensity mapping signal reconstruction: MeerKLASS and precision cosmology applications
• Detecting the relativistic bispectrum in 21cm intensity maps
• The degeneracy between primordial non-Gaussianity and foregrounds in 21cm intensity mapping experiments
• Detecting the power spectrum turnover with HI intensity mapping
• Linear bias and halo occupation distribution of emission line galaxies from Nancy Grace Roman Space Telescope
• Power spectrum multipole expansion for HI intensity mapping experiments: unbiased parameter estimation
• Large Scale Limit of the Observed Galaxy Power Spectrum
• Constraining primordial non-Gaussianity by combining next-generation galaxy and 21 cm intensity mapping surveys
• Multi-tracer power spectra and bispectra: Formalism
• Constraining the growth rate by combining multiple future surveys
• Multi-wavelength spectroscopic probes: biases from neglecting light-cone effects
• High-redshift cosmology with oxygen lines from H$\alpha$ surveys
• Phenomenological power spectrum models for H$\alpha$ emission line galaxies from the Nancy Grace Roman Space Telescope

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• Constraining primordial non-Gaussianity by combining photometric galaxy and 21cm intensity mapping surveys
• Multi-tracing the primordial Universe with future surveys
• Detecting Relativistic Doppler by Multi-Tracing a Single Galaxy Population
• The Baryon Budget of Galaxies across the First Billion Years
• Probing the large-scale structure with 21cm-galaxy cross-bispectrum: Estimates from simulations and forecasts for upcoming cosmological surveys