ABSTRACT
The theory of electromagnetic instabilities is more general than that of electrostatic ones, since the total set of the Maxwell equations is taken into account. This extension to electromagnetic effects turns out to be important mainly when the plasma pressure is not too small compared with the equilibrium magnetic field pressure. This chapter provides the basic equations of the theory of electromagnetic instabilities in a collisionless inhomogeneous plasma. It also provides the information about the equilibrium state of an inhomogeneous plasma with an inhomogeneous magnetic field. The chapter discusses the perturbed distribution functions. It explores the equilibrium magnetic field to be weakly inhomogeneous so that the characteristic length of the field inhomogeneity is large compared with the Larmor radius of the particle. The chapter explores the inhomogeneity of the plasma, as that of the magnetic field, to be sufficiently weak.
