The Jeans instability is regarded as an important tool for analyzing the dynamics of a self-gravitating system. However, this theory challenging since astronomical observation data show some Bok globules, whose masses are less than mass and still have stars or at least undergo star formation process. To explain problem, we investigate effects higher-order generalized uncertainty principle on co...

Abstract The generation of magnetohydrodynamic (MHD) waves and their instabilities are studied in galactic gaseous rotating plasmas with the effects magnetic field, self gravity, diffusion-convection cosmic rays as well gas cosmic-ray pressures. coupling Jeans, Alfvén magnetosonic waves, conditions damping or instability three different cases, namely when propagation direction is perpendicular,...

We present an extension of the Kompaneets equation which allows relativistic effects to be included to any desired order. Using this, we are able to obtain simple analytic forms for the spectral changes due to the Sunyaev-Zel’dovich effect in hot clusters, correct to first and second order in the expansion parameter θe = kBTe/mc . These analytic forms agree with previous numerical calculations ...

The timescale for star formation, a measure of how quickly neutral gas is being converted to stars, is considerably longer than typical dynamical timescales associated with a galactic disk. For purposes of modeling galaxy evolution, however, it would be extremely attractive if the star formation timescale were proportional to an easily derived dynamical timescale. We compare estimates of the st...

Abstract A survey of linearized cosmological fluid equations with a number of different matter components is made. To begin with, the one-component case is reconsidered to illustrate some important mathematical and physical points rarely discussed in the literature. The work of some previous studies of two-component systems are examined and re-analyzed to point out some deficiencies of solution...

One widely used technique for the construction of equilibrium models of stellar disks is based on the Jeans equations and the moments of velocity distribution functions derived using these equations. Stellar disks constructed using this technique are shown to be “not entirely” in equilibrium. Our attempt to abandon the epicyclic approximation and the approximation of infinite isothermal layers,...

Abstract. Fashion industry is currently one of the creative economy groups that has an influence on increase in Gross Domestic Product. Nos Jeans industries engaged jeans manufacturing sector which does not yet understand importance a marketing strategy. Problem occurred at NOS was decline purchasing power compared to it’s competitors exacerbated by condition Covid-19 virus pandemic caused sale...

We consider the problem of determining the structure of the dark halo of nearby dwarf spheroidal galaxies (dSphs) from the spherical Jeans equations. Whether the dark halos are cusped or cored at the centre is an important strategic problem in modern astronomy. The observational data comprise the line-of-sight velocity dispersion of a luminous tracer population. We show that when such data are ...