Abstract
We study static, spherically symmetric spacetimes in quadratic gravity. We show that using a conformal-to-Kundt ansatz leads to a considerable simplification of the vacuum field equations.
This simplification allows us to find Schwarzschild-Bach black hole in the form of a power series expansion with coefficients given by a recurrent formula. The Schwarzschild-Bach solution is specified by two parameters, the horizon position and an additional "non-Schwarzschild parameter" b that encodes the value of the Bach tensor on the horizon.
For vanishing "Bach" parameter, the Bach tensor vanishes as well and the Schwarzschild metric is recovered. The new form of the metric enables us to investigate the geometrical and physical properties of these black holes, such as tidal effects on test particles and thermodynamical quantities.