Reconstructing cosmic growth with kinetic Sunyaev-Zel'dovich observations in the era of stage IV experiments

Abstract

Future ground-based cosmic microwave background (CMB) experiments will generate competitive large-scale structure data sets by precisely characterizing CMB secondary anisotropies over a large fraction of the sky. We describe a method for constraining the growth rate of structure to sub-1% precision out to z≈1, using a combination of galaxy cluster peculiar velocities measured using the kinetic Sunyaev-Zel'dovich (kSZ) effect, and the velocity field reconstructed from galaxy redshift surveys. We consider only thermal SZ-selected cluster samples, which will consist of O(10^4–10^5) sources for Stage 3 and 4 CMB experiments respectively. Three different methods for separating the kSZ effect from the primary CMB are compared, including a novel blind "constrained realization" method that improves signal-to-noise by a factor of ∼2 over a commonly-used aperture photometry technique. Assuming a correlation between the integrated tSZ y-parameter and the cluster optical depth, it should then be possible to break the kSZ velocity-optical depth degeneracy. The effects of including CMB polarization and SZ profile uncertainties are also considered. In the absence of systematics, a combination of future Stage 4 experiments should be able to measure the product of the growth and expansion rates, α≡fH, to better than 1% in bins of Δz=0.1 out to z≈1—competitive with contemporary redshift-space distortion constraints from galaxy surveys. We conclude with a discussion of the likely impact of various systematics.

Additional Information

© 2016 American Physical Society. Received 8 April 2016; published 22 August 2016. We are grateful to Nicholas Battaglia, Jo Dunkley, Simone Ferraro, Sigurd Naess, and Emmanuel Schaan for useful comments and discussion. We also thank the anonymous referee, whose input improved the quality of the paper. D. A. is supported by the Beecroft Trust and ERC Grant No. 259505. T. L. is supported by ERC Grant No. 267117 (DARK) hosted by Universite Pierre et Marie Curie- Paris 6. P. B.'s research was supported by an appointment to the NASA Postdoctoral Program at the Jet Propulsion Laboratory, California Institute of Technology, administered by Universities Space Research Association under contract with NASA. P. G. F. acknowledges support from STFC, the Beecroft Trust and the Higgs Centre in Edinburgh.

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Submitted - 1604.01382v1.pdf

Published - PhysRevD.94.043522.pdf

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