MSc Defense: Final Oral Examination for the Degree of Master of Science of Karl Davidson

Event Details

  • Date:
  • Time: 10:00 AM
  • Location: MacN 415

Thesis Title:

“Electrostatic self-force as a probe of global structure”


The self-force is an effect which occurs when the force-field produced by an object interacts with the curvature of spacetime. The object then reacts to the modification of its own field and effectively exerts a force on itself – the self-force. In this work, I investigate the electrostatic self-force on an electric charge, as well as an electric dipole in a locally flat spacetime, to show that these self-forces probe the global curvature of the spacetime. This spacetime is produced by joining two versions of Minkowski space at a hypersurface of constant radial distance from either of its two centers. This connection produces a singular distribution of curvature on the hypersurface and thus also a thin shell of matter described by a perfect fluid.

I find that the self-force on a charge is always directed away from this surface layer, regardless of the sign of the charge. For the dipole, the direction of the force is dependent upon both the position and orientation of the dipole moment. Both self-forces are found to approach infinity as they are made to approach the surface layer.

Examination Committee:

  • Dr. Alexandros Gezerlis, Chair
  • Dr. Eric Poisson, Advisor
  • Dr. Liliana Caballero
  • Dr. Luis Lehner