Differential Invariants of the Kerr Vacuum

by

Kayll Lake

Short Version gr-qc/0308038
Longer Version with more and better images ps || pdf
The norms associated with the gradients of the two non-differential invariants of the Kerr vacuum are examined. Whereas both locally single out the horizons, their global behavior is more interesting. Both reflect the background angular momentum as the volume of space allowing a timelike gradient decreases with increasing angular momentum becoming zero in the degenerate and naked cases. These results extend directly to the Kerr-Newman geometry.