TY - JOUR

T1 - Third order solutions of cosmological density perturbations in Horndeski's most general scalar-tensor theory with the Vainshtein mechanism

AU - Takushima, Yuichiro

AU - Terukina, Ayumu

AU - Yamamoto, Kazuhiro

N1 - Publisher Copyright:
© 2015 American Physical Society.

PY - 2015/11/17

Y1 - 2015/11/17

N2 - We study the third order solutions of the cosmological density perturbations in Horndeski's most general scalar-tensor theory under the condition that the Vainshtein mechanism is at work. In this work, we thoroughly investigate the independence property of the functions describing the nonlinear mode couplings, which is also useful for models within general relativity. Then, we find that the solutions of the density contrast and the velocity divergence up to third order are characterized by six parameters. Furthermore, the one-loop order power spectra obtained with third order solutions are described by four parameters. We exemplify the behavior of the one-loop order power spectra assuming the kinetic gravity braiding model, which demonstrates that the effect of modified gravity appears more significantly in the power spectrum of the velocity divergence than the density contrast.

AB - We study the third order solutions of the cosmological density perturbations in Horndeski's most general scalar-tensor theory under the condition that the Vainshtein mechanism is at work. In this work, we thoroughly investigate the independence property of the functions describing the nonlinear mode couplings, which is also useful for models within general relativity. Then, we find that the solutions of the density contrast and the velocity divergence up to third order are characterized by six parameters. Furthermore, the one-loop order power spectra obtained with third order solutions are described by four parameters. We exemplify the behavior of the one-loop order power spectra assuming the kinetic gravity braiding model, which demonstrates that the effect of modified gravity appears more significantly in the power spectrum of the velocity divergence than the density contrast.

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U2 - 10.1103/PhysRevD.92.104033

DO - 10.1103/PhysRevD.92.104033

M3 - Article

AN - SCOPUS:84948798868

VL - 92

JO - Physical Review D - Particles, Fields, Gravitation and Cosmology

JF - Physical Review D - Particles, Fields, Gravitation and Cosmology

SN - 1550-7998

IS - 10

M1 - 104033

ER -