TY - JOUR

T1 - Instability in classical and modified gravity

AU - Arbuzova, E. V.

AU - Dolgov, A. D.

N1 - Publisher Copyright: © Cambridge Scientific Publishers and 2017 Astronomical and Astrophysical Transactions (AApTr).

PY - 2017

Y1 - 2017

N2 - Gravitational instability in classical Jeans theory, General Relativity, and modified gravity is considered. A simple suggestion to eliminate the problem with zero order approximation in the Jeans theory is proposed. It is shown that density perturbations in the background with an increasing density rise faster than in the standard case of time independent background. Evolution of density and metric perturbations in the background of high frequency oscillations of curvature in F(R) gravity is studied. In addition to the usual Jeans-like instability new effects of amplification of perturbations, associated with parametric resonance and antifriction phenomena, are found.

AB - Gravitational instability in classical Jeans theory, General Relativity, and modified gravity is considered. A simple suggestion to eliminate the problem with zero order approximation in the Jeans theory is proposed. It is shown that density perturbations in the background with an increasing density rise faster than in the standard case of time independent background. Evolution of density and metric perturbations in the background of high frequency oscillations of curvature in F(R) gravity is studied. In addition to the usual Jeans-like instability new effects of amplification of perturbations, associated with parametric resonance and antifriction phenomena, are found.

KW - General relativity

KW - Jeans theory

KW - Modified gravity

UR - http://www.scopus.com/inward/record.url?scp=85037731890&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:85037731890

VL - 30

SP - 31

EP - 46

JO - Astronomical and Astrophysical Transactions

JF - Astronomical and Astrophysical Transactions

SN - 1055-6796

IS - 1

ER -