Particle dynamics in the Kerr-Newman spacetime

Abstract

Physical theories are tested theoretically by means of considering thought (gedanken) experiments that is the quality of any theory rests on its breath of applicability to hitherto limiting scenarios; in addition they require the implicit or explicit notion of an observer that can make measurements on physical quantities in experiments. However there is a conflict between the role of observers in quantum and classical theory, particularly in classical theory an observer is al ways present and so every parameter of an experiment must be well defined at all points in time whereas in the quantum theory observers must make observations and so parameters of an experiment may vary between such measurements which led to theorems as the energy-time uncertainty principle where a limit is set on the amount of information an observer may acquire about any system. Thus in the quantum theory observers are making measurements at finite discrete in stances and so have are rarely present in the experiment, as opposed to classical physics where an observer, in the form of a coordinate system of some sort is ever measuring the dynamical quantities. Furthermore quantum theory employs the Newtonian notion of time which contrasts with general relativity which al lows observers to measure the passage of time differently. The general theory of relativity will be first introduced with a focus on the role of observers and in particular a brief discussion on the specific observers that will be used. Thereafter a short introduction is given on the topic of black holes, where all spherically collapsing black holes will be introduced and an emphasis will be given to the particular black hole that is to be discussed (the Kerr-Newman black hole). Two gedanken experiments are considered. The first involves the fate of the EPR experiment near the Kerr-Newman black hole and the apparent loss of information that follows from the induced curvature of spacetime near the black hole under consideration. Due to this curvature a precession angle of the spin states is observed, the angle is given explicitly. However even a freely falling observer cannot make measurements of the EPR correlation when the observer is less than a certain specific distance from the black hole (the horizon). An account is given for this feature. After this some high energy physics is considered in the vicinity of the Kerr-Newman black hole, in particular two particles are let collide and observations on the collision are made in the lab frame of the collision; it is found that the center mass energy becomes arbitrary for a special scenario of such a Kerr-Newman black hole, and lost again in the general case of charged black holes. It is expected however that the arbitrary center-of-mass measurement is removed when gravitational radiation is considered.