Black holes and other spherical solutions in quadratic gravity with a cosmological constant

Understand

We study static spherically symmetric solutions to the vacuum field equations of quadratic gravity in the presence of a cosmological constant $\Lambda$.

• Motivated by the trace no-hair theorem, we assume the Ricci scalar to be constant throughout a spacetime.
• Furthermore, we employ the conformal-to-Kundt metric ansatz that is valid for all static spherically symmetric spacetimes and leads to a considerable simplification of the field equations.
• We arrive at a set of two ordinary differential equations and study its solutions using the Frobenius-like approach of (infinite) power series expansions.