Dynamics Of Self-gravitating Systems Research Articles

Jeans instability of predictive model of baryonic and fermionic dark matter with the impact of dissipative force

This study examines the Jeans instability and growth rate of a self-gravitating system made up of baryonic particles and dark matter with a source of dissipation. While treating dark matter using a quantum damped-hydrodynamic technique, we employed the classical hydrodynamic fluid approach for baryonic particles. We get the coupled system's dispersion relation by evaluating the equations. We examine the dispersion relation and the Jeans condition in various limiting circumstances and demonstrate how parameters influence growth rate with the use of graphical instances. We discovered that, irrespective of the jeans wave number, the dissipation source damps the growth rate. The study highlights how the introduction of dissipation influences the growth rate and damping effect observed in the system. Overall, the findings of this study provide valuable insights into the dynamics of self-gravitating systems and their evolution over time.

Dynamics of self-gravitating systems in non-linearly magnetized chameleonic Brans–Dicke gravity

We study the effects of magnetic fields of non-linear electrodynamics in chameleonic Brans-Dicke theory under the existence of anisotropic spherical fluid. In particular, we explore dissipative and non-dissipative self-gravitating systems in the quasi-homologous regime with the minimal complexity constraint. As a result, under the aforementioned circumstances, several analytic solutions are found. Furthermore, by analyzing the dynamics of a dissipative fluid, it is demonstrated that a void covering the center can satisfy the Darmois criteria. The temperature of the self gravitating systems is also investigated.

N-body chaos and the continuum limit in numerical simulations of self-gravitating systems, revisited

ABSTRACTWe revisit the role of discreteness and chaos in the dynamics of self-gravitating systems by means of N-body simulations with active and frozen potentials, starting from spherically symmetric stationary states and considering the orbits of single particles in a frozen N-body potential as well as the orbits of the system in the full 6N-dimensional phase space. We also consider the intermediate case where a test particle moves in the field generated by N non-interacting particles, which in turn move in a static smooth potential. We investigate the dependence on N and on the softening length of the largest Lyapunov exponent both of single particle orbits and of the full N-body system. For single orbits, we also study the dependence on the angular momentum and on the energy. Our results confirm the expectation that orbital properties of single orbits in finite N systems approach those of orbits in smooth potentials in the continuum limit N → ∞ and that the largest Lyapunov exponent of the full N-body system does decrease with N, for sufficiently large systems with finite softening length. However, single orbits in frozen models and active self-consistent models have different largest Lyapunov exponents and the N-dependence of the values in non-trivial, so that the use of frozen N-body potentials to gain information on large N systems or on the continuum limit may be misleading in certain cases.

Dynamics of relativistic fluids with structure scalars and $$\epsilon R^2$$ ϵ R 2 cosmology

This work is devoted to analyze the effects of $$f(R)$$ model on the dynamics of dissipative shearing viscous and anisotropic spherical matter configuration. In this framework, we develop scalar functions and link their expressions with various physical parameters and inflationary $$f(R)$$ dark source terms. We also relate the Weyl tensor as well as other matter variables with $$R+{\epsilon }R^2$$ background and obtain evolution equations for shear and expansion scalars. We conclude that structure scalars and $$f(R)$$ higher curvature terms have significant importance in the dynamics of self-gravitating systems.

The structure, stability, and dynamics of self-gravitating systems

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Dynamics of Self-Gravitating Systems: Structure of Galaxies

Dynamics of Self-Gravitating Systems: Structure of Galaxies