Testing general relativity on cosmological scales at redshift z ~ 1.5 with quasar and CMB lensing

Journal Article · 25 November 2020 · Monthly Notices of the Royal Astronomical Society

DOI: https://doi.org/10.1093/mnras/staa3672 · OSTI ID:1745064

Zhang, Yucheng  ^[1]; Pullen, Anthony R. ^[2]; Alam, Shadab  ^[3]; Singh, Sukhdeep ^[4]; Burtin, Etienne ^[5]; Chuang, Chia-Hsun  ^[6]; Hou, Jiamin ^[7]; Lyke, Brad W. ^[8]; Myers, Adam D. ^[8]; Neveux, Richard ^[5]; Ross, Ashley J.  ^[9]; Rossi, Graziano ^[10]; Zhao, Cheng  ^[11]

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1. New York Univ. (NYU), NY (United States)
2. New York Univ. (NYU), NY (United States); Flatiron Institute, New York, NY (United States)
3. Univ. of Edinburgh, Scotland (United Kingdom). The Royal Observatory
4. Univ. of California, Berkeley, CA (United States)
5. Univ. Paris-Saclay, Gif-sur-Yvette (France)
6. Stanford Univ., CA (United States). Kavli Institute for Particle Astrophysics & Cosmology
7. Max Planck Inst. fuer Extraterrestrische Physik, Garching (Germany)
8. Univ. of Wyoming, Laramie, WY (United States)
9. The Ohio State Univ., Columbus, OH (United States)
10. Sejong Univ., Seoul (Korea, Republic of)
11. Ecole Polytechnique Federale Lausanne (Switzerland)

In this work, we test general relativity (GR) at the effective redshift $$\bar{z} \sim 1.5$$ by estimating the statistic EG, a probe of gravity, on cosmological scales $$19 - 190\, h^{-1}{\rm Mpc}$$. This is the highest redshift and largest scale estimation of EG so far. We use the quasar sample with redshifts 0.8 < z < 2.2 from Sloan Digital Sky Survey IV extended Baryon Oscillation Spectroscopic Survey Data Release 16 as the large-scale structure (LSS) tracer, for which the angular power spectrum $$C_\ell ^{qq}$$ and the redshift-space distortion parameter β are estimated. By cross-correlating with the Planck 2018 cosmic microwave background (CMB) lensing map, we detect the angular cross-power spectrum $$C_\ell ^{\kappa q}$$ signal at $$12\, \sigma$$ significance. Both jackknife resampling and simulations are used to estimate the covariance matrix (CM) of EG at five bins covering different scales, with the later preferred for its better constraints on the covariances. We find EG estimates agree with the GR prediction at $$1\, \sigma$$ level over all these scales. With the CM estimated with 300 simulations, we report a best-fitting scale-averaged estimate of $$E_G(\bar{z})=0.30\pm 0.05$$, which is in line with the GR prediction $$E_G^{\rm GR}(\bar{z})=0.33$$ with Planck 2018 CMB + BAO matter density fraction Ωm = 0.31. The statistical errors of EG with future LSS surveys at similar redshifts will be reduced by an order of magnitude, which makes it possible to constrain modified gravity models.

• Research Organization: Univ. of Wyoming, Laramie, WY (United States)
• Sponsoring Organization: USDOE Office of Science (SC), High Energy Physics (HEP); National Aeronautics and Space Administration (NASA); European Research Council (ERC); National Research Foundation of Korea (NRF); USDOE
• Grant/Contract Number: SC0019022; 80NSSC18K1014; NNH17ZDA001N; 670193; 2017R1E1A1A01077508; 2020R1A2C1005655
• OSTI ID: 1745064
• Alternate ID(s): OSTI ID: 1787340
• Journal Information: Monthly Notices of the Royal Astronomical Society, Vol. 501, Issue 1; ISSN 0035-8711
• Publisher: Royal Astronomical SocietyCopyright Statement
• Country of Publication: United States
• Language: English