ИСТИНА

We propose a method described in \cite{Anik-1} for calculating asymptotic solutions of stationary problems for differential (or pseudodifferential) operators whose symbol is a self-adjoint matrix. We show that the problem of constructing asymptotic solutions corresponding to a fixed eigenvalue (called an effective Hamiltonian, term, or mode) reduces to studying objects related only to the determinant of the principal matrix symbol and the eigenvector corresponding to a given (numerical) value of this effective Hamiltonian. We apply this method in a linearized $12\times 12$ system describing plasma motion (e.g. in tokamak). This work was supported by the RFBR grant 18-31-00273.