Time Machines and AdS Solitons with Negative Mass

Understand

We show that in D=2n+1 dimensions, when mass is negative and all angular momenta are non-vanishing, Kerr and Kerr-AdS metrics describe smooth time machines, with no curvature singularity.

• Turning off the angular momenta appropriately can lead to static AdS solitons with negative mass.
• Setting zero the cosmological constant yields a class of Ricci-flat K\"ahler metrics in D=2n dimensions.
• We also show that Euclidean-signatured AdS solitons with negative mass can also arise in odd dimensions.