C-metric with a conformally coupled scalar field in a magnetic universe

Understand

In Einstein-Maxwell gravity with a conformally coupled scalar field, the black hole found by Bocharova, Bronnikov, Melnikov, and Bekenstein breaks when embedded in the external magnetic field of the Melvin universe.

• The situation improves in presence of acceleration, allowing one to build magnetised and accelerating BBMB black hole with a thin membrane.
• But to overcome this and others disadvantages of BBMB spacetimes, a new class of black holes, including the rotating case, is proposed for the conformal matter coupling under consideration.