Speaker
Description
Spacetimes with NUT parameter are known to posses a string-like conical singularity. We present a method for obtaining non-singular Kerr-NUT spacetimes with an arbitrary cosmological constant, via an analogue of the Misner interpretation of Taub-NUT spacetimes. Among the non-singular solution there is a class for which also one of the horizons is projectively non-singular, i.e. its space of null generators is non-singular. The horizon is found to be always a cosmological one (but possibly with a negative mass) and non-extremal. The topology of such non-singular horizon is of a non-trivial bundle of $U(1)$ over $S^2$ and can be extended onto the spacetime in such way that the global topology is $S^3 \times \mathbb{R}$. We provide a geometric interpretation of the non-singular structures on the spacetime, our approach relies on the space of orbits of the Killing vector field of a particular Killing vector field.
