Constraining modified theories of gravity with the galaxy bispectrum
Abstract
We explore the use of the galaxy bispectrum induced by the nonlinear gravitational evolution as a possible probe to test general scalar-tensor theories with second-order equations of motion. We find that time dependence of the leading second-order kernel is approximately characterized by one parameter, the second-order index, which is expected to trace the higher-order growth history of the Universe. We show that our new parameter can significantly carry new information about the nonlinear growth of structure. We forecast future constraints on the second-order index as well as the equation-of-state parameter and the growth index.
- Publication:
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Physical Review D
- Pub Date:
- December 2017
- DOI:
- 10.1103/PhysRevD.96.123516
- arXiv:
- arXiv:1709.03243
- Bibcode:
- 2017PhRvD..96l3516Y
- Keywords:
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- Astrophysics - Cosmology and Nongalactic Astrophysics
- E-Print:
- 15 pages, 2 figures