The Subaru FMOS galaxy redshift survey (FastSound). IV. New constraint on gravity theory from redshift space distortions at z 1.4

Teppei Okumura, Chiaki Hikage, Tomonori Totani, Motonari Tonegawa, Hiroyuki Okada, Karl Glazebrook, Chris Blake, Pedro G. Ferreira, Surhud More, Atsushi Taruya, Shinji Tsujikawa, Masayuki Akiyama, Gavin Dalton, Tomotsugu Goto, Takashi Ishikawa, Fumihide Iwamuro, Takahiko Matsubara, Takahiro Nishimichi, Kouji Ohta, Ikkoh ShimizuRyuichi Takahashi, Naruhisa Takato, Naoyuki Tamura, Kiyoto Yabe, Naoki Yoshida

Research output: Contribution to journalReview articlepeer-review

166 Citations (Scopus)


We measure the redshift-space correlation function from a spectroscopic sample of 2783 emission line galaxies from the FastSound survey. The survey, which uses the Subaru Telescope and covers a redshift range of 1.19 < z < 1.55, is the first cosmological study at such high redshifts. We detect clear anisotropy due to redshift-space distortions (RSD) both in the correlation function as a function of separations parallel and perpendicular to the line of sight and its quadrupole moment. RSD has been extensively used to test general relativity on cosmological scales at z < 1. Adopting a CDM cosmology with the fixed expansion history and no velocity dispersion (v = 0), and using the RSD measurements on scales above 8 h1 Mpc, we obtain the first constraint on the growth rate at the redshift, f (z)8(z) = 0.482 ± 0.116 at z 1.4 after marginalizing over the galaxy bias parameter b(z)8(z). This corresponds to 4.2 detection of RSD. Our constraint is consistent with the prediction of general relativity f8 0.392 within the 1 confidence level. When we allow v to vary and marginalize over it, the growth rate constraint becomes f 8 = 0.494+0.126 0.120. We also demonstrate that by combining with the low-z constraints on f8, high-z galaxy surveys like the FastSound can be useful to distinguish modified gravity models without relying on CMB anisotropy experiments.

Original languageEnglish
Article number38
JournalPublication of the Astronomical Society of Japan
Issue number3
Publication statusPublished - 2016 Jun 1


  • Cosmological parameters-cosmology
  • Data analysis
  • Distances and redshifts-methods
  • Large-scale structure of universe-cosmology
  • Observations-galaxies


Dive into the research topics of 'The Subaru FMOS galaxy redshift survey (FastSound). IV. New constraint on gravity theory from redshift space distortions at z 1.4'. Together they form a unique fingerprint.

Cite this