Dynamics of Axial Symmetric System in Self-Interacting Brans-Dicke Gravity

TL;DR

This study explores the stability and oscillation behavior of an axial symmetric system within self-interacting Brans-Dicke gravity, highlighting the influence of dark energy, anisotropy, and reflection effects on stability.

Contribution

It provides a detailed analysis of oscillations and stability criteria in axial symmetric models in Brans-Dicke gravity, including new formulations of hydrodynamical equations and perturbation analysis.

Findings

Oscillations depend on dark energy and anisotropy.

System stable at stiffness parameter $oxed{ ext{1}}$, collapses for $oxed{ ext{>1}}$, unstable for $0<oxed{ ext{<1}}$.

Abstract

This paper investigates dynamics of axial reflection symmetric model in self-interacting Brans-Dicke gravity for anisotropic fluid. We formulate hydrodynamical equations and discuss oscillations using time-dependent perturbation for both spin as well as spin-independent cases. The expressions of frequency, total energy density and equation of motion of oscillating model are obtained. We study instability of oscillating models in weak approximations. It is found that the oscillations and stability of the model depend upon the dark energy source along with anisotropy and reflection effects. We conclude that the axial reflection system remains stable for stiffness parameter $\Gamma=1$, collapses for $\Gamma>1$ and becomes unstable for $0<\Gamma<1$.