TY - JOUR

T1 - Relativistic effects and primordial non-Gaussianity in the matter density fluctuation

AU - Yoo, Jaiyul

AU - Gong, Jinn Ouk

N1 - Funding Information:
We acknowledge useful discussions with Mehrdad Mirbabayi and David Wands. We are especially grateful to Matias Zaldarriaga for the critical comments on the manuscript and Jai-chan Hwang for sharing his unpublished results, to which we compare our results. J.Y. is supported by the Swiss National Science Foundation . J.G. is supported by the Independent Junior Research Fellowship and by a Starting Grant through the Basic Science Research Program of the National Research Foundation of Korea ( 2013R1A1A1006701 ).
Publisher Copyright:
© 2016 The Authors.

PY - 2016/3/10

Y1 - 2016/3/10

N2 - We present the third-order analytic solution of the matter density fluctuation in the proper-time hypersurface of nonrelativistic matter flows by solving the nonlinear general relativistic equations. The proper-time hypersurface provides a coordinate system that a local observer can set up without knowledge beyond its neighborhood, along with physical connections to the local Newtonian descriptions in the relativistic context. The initial condition of our analytic solution is set up by the curvature perturbation in the comoving gauge, clarifying its impact on the nonlinear evolution. We compute the effective non-Gaussian parameters due to the nonlinearity in the relativistic equations. With proper coordinate rescaling, we show that the equivalence principle is respected and the relativistic effect vanishes in the large-scale limit.

AB - We present the third-order analytic solution of the matter density fluctuation in the proper-time hypersurface of nonrelativistic matter flows by solving the nonlinear general relativistic equations. The proper-time hypersurface provides a coordinate system that a local observer can set up without knowledge beyond its neighborhood, along with physical connections to the local Newtonian descriptions in the relativistic context. The initial condition of our analytic solution is set up by the curvature perturbation in the comoving gauge, clarifying its impact on the nonlinear evolution. We compute the effective non-Gaussian parameters due to the nonlinearity in the relativistic equations. With proper coordinate rescaling, we show that the equivalence principle is respected and the relativistic effect vanishes in the large-scale limit.

UR - http://www.scopus.com/inward/record.url?scp=84955610545&partnerID=8YFLogxK

U2 - 10.1016/j.physletb.2016.01.021

DO - 10.1016/j.physletb.2016.01.021

M3 - Article

AN - SCOPUS:84955610545

SN - 0370-2693

VL - 754

SP - 94

EP - 98

JO - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics

JF - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics

ER -