Solutions of the Einstein-Dirac and Seiberg-Witten Monopole Equations

This article presents a new and more elementary proof of the main Seiberg-Witten-based obstruction to the existence of Einstein metrics on smooth compact 4-manifolds. It also introduces a new smooth manifold invariant which conveniently encapsulates those aspects of Seiberg-Witten theory most relevant to the study of Riemannian variational problems on 4-manifolds.

Alternative theories of gravity and their solutions are of considerable importance since at some fundamental level the world can reveal new features. Indeed, it is suspected that the gravitational field might be nonminimally coupled to the other fields at scales not yet probed, bringing into the forefront nonminimally coupled theories. In this mode, we consider a nonminimal Einstein-Yang-Mills theory with a cosmological constant. Imposing spherical symmetry and staticity for ...

We show that in the Maxwell-Chern-Simons theory of topologically massive electrodynamics the Dirac string of a monopole becomes a cone in anti-de Sitter space with the opening angle of the cone determined by the 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, {\it a priory} completely unrelated to gravity, which nevertheless requires curved spacetime for its very existence. We extend...

Starting from the geometrical interpretation of integrable vortices on two-dimensional hyperbolic space as conical singularities, we explain how this picture can be expressed in the language of Cartan connections, and how it can be lifted to the double cover of three-dimensional Anti-de Sitter space viewed as a trivial circle bundle over hyperbolic space. We show that vortex configurations on the double cover of AdS space give rise to solutions of the Dirac equation minimally...

In this paper, we argue that the elusive magnetic monopole arises due to the strong magnetic effects arising from the non commutative space time structure at small scales.If this structure is ignored and we work with Minkowski spacetime, then the magnetic effect shows up as a monopole. This would also explain why the monopole has eluded detection even after seventy years. We next consider anaother area in which Solitons can be applied, viz., Bose Einstein condensation.

In a previous work the Weyl-Dirac framework was generalized in order to obtain a geometrically based general relativistic theory, possessing intrinsic electric and magnetic currents and admitting massive photons. Some physical phenomena in that framework are considered. So it is shown that massive photons may exist only in presence of an intrinsic magnetic field. The role of massive photons is essential in order to get an interaction between magnetic currents. A static spheri...

In a previous paper, we found an extension of the N-dimensional Lorentz generators that partially restores the closed operator algebra in the presence of a Maxwell field, and is conserved under system evolution. Generalizing the construction found by Berard, Grandati, Lages and Mohrbach for the angular momentum operators in the O(3)-invariant nonrelativistic case, we showed that the construction can be maximally satisfied in a three dimensional subspace of the full Minkowski ...

In this paper we apply the techniques which have been developed over the last few decades for generating nontrivially new solutions of the Einstein-Maxwell equations from seed solutions for simple spacetimes. The simple seed spacetime which we choose is the "magnetic universe" to which we apply the Ehlers transformation. Three interesting non-singular metrics are generated. Two of these may be described as "rotating magnetic universes" and the third as an "evolving magnetic u...

We compute the Yamabe invariants for a new infinite class of closed $4$-dimensional manifolds by using a "twisted" version of the Seiberg-Witten equations, the $\mathrm{Pin}^-(2)$-monopole equations. The same technique also provides a new obstruction to the existence of Einstein metrics or long-time solutions of the normalised Ricci flow with uniformly bounded scalar curvature.

Starting with an $n$-dimensional oriented Riemannian manifold with a Spin-c structure, we describe an elliptic system of equations which recover the Seiberg-Witten equations when $n=3,4$. The equations are for a U(1)-connection $A$ and spinor $\phi$, as usual, and also an odd degree form $\beta$ (generally of inhomogeneous degree). From $A$ and $\beta$ we define a Dirac operator $D_{A,\beta}$ using the action of $\beta$ and $*\beta$ on spinors (with carefully chosen coefficie...