Spiral structure of disk galaxies and hidden mass effect

Background. A theory of disk galaxies with a violation of cylindrical symmetry is being constructed, which solves the problem of the spiral structure of galaxies within the framework of a general density wave model. Materials and methods. The theory is based on the classical hydrodynamics of a continuous self-gravitating medium with a quasiclassical gravitational field containing a description of the effect of hidden mass (dark matter). Results. The equations of the spatial distribution of the parameters of the medium and the gravitational field, as well as the equations of the evolution of scale factors, are derived under the conditions of dynamic equilibrium of a rotating medium with a violation of cylindrical symmetry. An analogy is established between the effect of hidden mass and the gravitational permeability of the medium. The description of the interaction of the disk structure with the external environment is considered. Conclusions. The theory allows us to build models of disk galaxies with a spiral structure in the presence of a hidden mass effect. Such models include descriptions of the intrinsic evolution of disk galaxies in the presence of external influences.