Electrostatic self-force in (2+1)-dimensional cosmological gravity
  Point sources in (2+1)-dimensional gravity are conical singularities that modify the global curvature of the space giving rise to self-interaction effects on classical fields. In this work we study the electrostatic self-interaction of a point charge in the presence of point masses in (2+1)-dimensional gravity with a cosmological constant. 
Claudio Furtado and Fernando Moraes