Abstrakt
We present a newexplicit class of black holes in general quadratic gravity with a cosmological constant. These spherically symmetric Schwarzschild-Bach-(anti-)de Sitter geometries, derived under the assumption of constant scalar curvature, form a three-parameter family determined by the black-hole horizon position, the value of the Bach invariant on the horizon, and the cosmological constant.
Using a conformal to Kundt metric ansatz, the fourth-order field equations simplify to a compact autonomous system. Its solutions are found as power series, enabling us to directly set the Bach parameter and/or cosmological constant equal to zero.
To interpret these spacetimes, we analyze the metric functions. Inparticular,wedemonstratethatforacertainrangeofpositivecosmologicalconstanttherearebothblackhole and cosmological horizons, with a static region between them.
The tidal effects on free test particles and basic thermodynamic quantities are also determined.