Constraining the growth rate on linear scales by combining SKAO and DESI surveys

Abstract

In the pursuit of understanding the large-scale structure of the Universe, the synergy between complementary cosmological surveys has proven to be a powerful tool. Using multiple tracers of the large-scale structure can significantly improve the constraints on cosmological parameters. We explore the potential of combining the Square Kilometre Array Observatory (SKAO) and the Dark Energy Spectroscopic Instrument (DESI) spectroscopic surveys to enhance precision on the growth rate of cosmic structures. We employ a multitracer Fisher analysis to estimate precision on the growth rate when using pairs of mock surveys that are based on SKAO and DESI specifications. The pairs are at both low and high redshifts. For SKA-MID, we use the HI galaxy and the HI intensity mapping samples. In order to avoid the complexities and uncertainties at small scales, we confine the analysis to scales where linear perturbations are reliable. The consequent loss of signal in each individual survey is mitigated by the gains from the multi-tracer. After marginalising over cosmological and nuisance parameters, we find a significant improvement in the precision on the growth rate.

12 pages, 8 figures

References in corpus (17)

• Measuring primordial non-gaussianity without cosmic variance
• Late-time cosmology with 21cm intensity mapping experiments
• The Tianlai project: a 21cm cosmology experiment
• SKAO HI Intensity Mapping: Blind Foreground Subtraction Challenge
• On the impact of galaxy bias uncertainties on primordial non-Gaussianity constraints
• The Completed SDSS-IV extended Baryon Oscillation Spectroscopic Survey: a multi-tracer analysis in Fourier space for measuring the cosmic structure growth and expansion rate
• Information content in the redshift-space galaxy power spectrum and bispectrum
• On the importance of lensing for galaxy clustering in photometric and spectroscopic surveys
• Joint growth rate measurements from redshift-space distortions and peculiar velocities in the 6dF Galaxy Survey
• Detecting the relativistic bispectrum in 21cm intensity maps
• Measuring the growth of structure with intensity mapping surveys
• The degeneracy between primordial non-Gaussianity and foregrounds in 21cm intensity mapping experiments
• Constraining primordial non-Gaussianity by combining next-generation galaxy and 21 cm intensity mapping surveys
• Constraining the growth rate by combining multiple future surveys
• Validating the Fisher approach for stage IV spectroscopic surveys
• Multipole expansion for 21cm Intensity Mapping power spectrum: forecasted cosmological parameters estimation for the SKA Observatory
• Baryon acoustic oscillations from HI intensity mapping: the importance of cross-correlations in the monopole and quadrupole