Optimising growth of structure constraints on modified gravity

Louis Perenon, Julien Bel, Roy Maartens, Alvaro de la Cruz-Dombriz

Research output: Contribution to journalArticlepeer-review

22 Downloads (Pure)

Abstract

We use growth of structure data to constrain the effective field theory of dark energy. Considering as case study Horndeski theories with the speed of gravitational waves equal to that of light, we show how constraints on the free parameters and the large-scale structure phenomenological functions can be improved by two ingredients: firstly by complementing the set of redshift-space distortions data with the three recent measurements of the growth rate ƒ and the amplitude of matter fluctuations σ8 from the VIPERS and SDSS collaborations; secondly by applying a local Solar System bound on the variation of the Newton constant. This analysis allows us to conclude that: i) despite firmly restricting the predictions of weaker gravity, the inclusion of the Solar System bound does not prevent suppressed growth relative to the standard model ΛCDM at low redshifts; ii) the same bound in conjunction with the growth of structure data strongly restricts the redshift evolution of the gravitational slip parameter to be close to unity and the present value is constrained to one at the 10-3 level; iii) the growth of structure data favours a fifth force contribution to the effective gravitational coupling at low redshifts and at more than one sigma at present time.
Original languageEnglish
Article number020
Number of pages30
JournalJournal of Cosmology and Astroparticle Physics
Volume6
DOIs
Publication statusPublished - 10 Jun 2019

Keywords

  • astro-ph.CO
  • RCUK
  • STFC
  • ST/N000668/1
  • dark energy
  • modified gravity
  • Horndeski theories
  • large-scale structure

Fingerprint

Dive into the research topics of 'Optimising growth of structure constraints on modified gravity'. Together they form a unique fingerprint.

Cite this