Kundt spacetimes as solutions of topologically massive gravity

Understand

We obtain new solutions of topologically massive gravity.

• We find the general Kundt solutions, which in three dimensions are spacetimes admitting an expansion-free null geodesic congruence.
• The solutions are generically of algebraic type II, but special cases are types III, N or D.
• Those of type D are the known spacelike-squashed AdS_3 solutions, and of type N are the known AdS pp-waves or new solutions.