Study On The Jeans Instability In Self-Gravitational Systems Composed By Dark Matter

Jeans instability describes the collapse of celestial structures under the action of self-gravitation.Since it is considered to be one of the key mechanisms that explain the formation of the self-gravitational system structure and its evolution in a linear state,it has been extensively studied in the fields of astrophysics,plasma,and dusty plasma.However,in the past,studies involving Jeans instability were mostly limited by theoretical models at the time.The conventional research did not consider the effects of dark matter,modified gravity and other factors on the entire system,which made it impossible to explain the collapse of some giant cold molecular clouds in the process of star formation.Therefore,a large number of researchers have carried out work on how to modify the existing theoretical models to explain these special physical phenomena.Recently,the theory of millicharged dark matter and the discovery that dark matter particles satisfy the non-Maxwell distribution function have provided important clues for solving the above problems.Dark matter theory has been proved by a large amount of observational evidence,and has been well studied and applied in astrophysics.However,the nature of dark matter is still an unsolved mystery,and research on the influence of dark matter on the formation of celestial bodies still needs to be perfected.On the other hand,as an alternative theory to the dark matter model,researchers have proposed to solve some strange phenomena in astrophysics with the modified gravitational theory.Especially,Eddington-Born-Infeld-Einstein(EiBI)gravity theory has received extensive attention and research due to its unique properties.Based on plasma kinetic theory,plasma fluid theory and numerical calculation methods,this paper discusses the influence of dark matter with different characteristics on the Jeans instability of self-gravitation system.At the same time,based on the EiBI modified gravitational theory,the Jeans instability in the self-gravitational system under the EiBI gravitational background is studied.The main research results are showed as follows:1)Dark matter is conducive to the formation of the self-gravitational system structure,especially for interstellar clouds,and the existence of dark matter accelerates the process of star formation;2)Under the background of different statistical distributions,the Jeans instability in the self-gravitational system composed of bright and dark matter will show different physical phenomenons;3)The millicharged charged dark matter can effectively suppress the collapse of the self-gravitational system and generate a dark matter sound wave.It may be the key to explaining the collapse time scale of some giant cold molecular clouds;4)EiBI gravity can only act on self-gravitational systems in high-density environments,and it can aggravate the instability of high-density self-gravitational systems.It also makes it possible for the neutron star to collapse into a black hole.However,in a low-density environment,EiBI gravity will not affect the Jeans instability.