ON THE KINEMATICS OF A COROTATING RELATIVISTIC PLASMA STREAM IN THE PERPENDICULAR ROTATOR MODEL OF A PULSAR MAGNETOSPHERE

An investigation of the kinematics of a rotating relativistic plasma s tream in the perpendicular rotator model of the pulsar magnetosphere i s presented. It is assumed that the plasma (ejected from the pulsar) m oves along the pulsar magnetic field lines and also corotates with the m. The field lines are considered to be radial straight lines, located in the plane which is perpendicular to the pulsar rotation axis. The necessity of taking particle inertia into account is discussed. It is argued that the ''massless'' (''force-free'') approximation cannot be used for the description of this problem. The frame selection is discu ssed and it is shown that it is convenient to discuss the problem in t he noninertial frame of ZAMOs (Zero Angular Momentum Observers). The e quation of motion and the exact set of equations describing the behavi our of a relativistic plasma stream in the pulsar magnetosphere is obt ained. The possible relevance of this investigation for the understand ing of the formation process of a pulsar magnetosphere is discussed.