טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
Ph.D Thesis
Ph.D StudentRosenthal Eran
SubjectThe Self Force in Curved Spacetime
DepartmentDepartment of Physics
Supervisor Professor Amos Ori


Abstract

This research includes two main topics: first, a consistent formulation of the extended-object approach for the explanation and calculation of the self-force  phenomenon in flat spacetime. In this approach, one considers a charged extended-object of a finite size  that accelerates in a nontrivial manner, and calculates the total  force exerted on it by the electromagnetic field (whose source is the charged object itself), at the limit . Previous study of this approach ended up with expressions  for the total electromagnetic force that do not have the form required by mass-renormalization (in the special case of a spherical charge distribution, this  term was  found to be 4/3 times larger than the desired quantity). In this thesis we use energy-momentum conservation in the object's momentary rest frame, and derive the correct  notion of total electromagnetic force. This completely cures the problematic O(1/) term, for any object's shape, and yields the correct self-force at the limit .

 In particular, for a spherical charge distribution, the above ''4/3 problem'' is resolved.        


The second topic in this research is the derivation and implementation of a new regularization approach for the calculation of the scalar self-force in curved spacetime.

 In this approach the scalar self-force in curved spacetime is expressed in terms of the difference between two retarded scalar fields: the massless scalar field, and an  auxiliary massive scalar field. This field difference combined with a certain limiting process gives a simple expression for the scalar self-force. We implement this approach  in the special case of static particle in a Schwarzschild spacetime, thereby we show that the scalar self-force vanishes in this case.