Topologically massive magnetic monopoles

We show that in the Maxwell-Chern-Simons theory of topologically massive el ectrodynamics the Dirac string of a monopole becomes a cone in anti-de Sitt er space with the opening angle of the cone determined by topological mass, which in turn is related to the square root of the cosmological constant. This proves to be an example of a physical system, a priori completely unre lated to gravity, which nevertheless requires curved spacetime for its very existence. We extend this result to topological massive gravity coupled to topologically massive electrodynamics within the framework of the theory o f Deser, Jackiw and Templeton. The two-component spinor formalism, which is a Newman-Penrose type approach for three dimensions, is extended to includ e both the electrodynamical and gravitational topologically massive field e quations. Using this formalism exact solution of the coupled Deser-Jackiw-T empleton and Maxwell-Chern-Simons field equations for a topologically massi ve monopole are presented. These are homogeneous spaces with conical defici t. Pure Einstein gravity coupled to the Maxwell-Chern-Simons field does not admit such a monopole solution.