Static and dynamic charged black holes

Abstract

We consider a class of Einstein-Maxwell-dilaton theories in general dimensions and construct both static and dynamic charged black holes. We adopt the reverse engineering procedure and make a specific ansatz for the scalar field and then derive the necessary scalar potential and the non-minimal coupling function between the scalar and the Maxwell field. The resulting static black holes contain mass and electric charge as integration constants. We find that some of the static solutions can be promoted to become dynamical ones in the Eddington-Finkelstein-like coordinates. The collapse solutions describe the evolution from a smaller charged black hole to a larger black hole state, driven by the scalar field.

Charged Ellis wormhole and black bounce

“…The paper is organized as follows. In section 2, we review the theory and the solutions constructed in Ref [1] and present new solutions by making the transformation of the scalar φ to iφ, together with some appropriate changes of the parameters in the theory. We then make a coordinate change so that the solution can describe the whole spacetime.…”

“…

By replacing the scalar φ with iφ in the solution constructed in Ref [1], we obtain electrically-charged wormhole and black hole solutions in the Einstein-Maxwell-scalar theory, in which the scalar is a phantom field coupled to the Maxwell field non-minimally.Our solutions are simpler than the previously-known charged wormholes in the Einstein-Maxwell-dilaton theory in that both the scalar and the radius of the foliating sphere of our solutions are independent of electric charge. The wormhole solution has two asymptotically flat regions and reduces to Ellis wormhole when the charge is zero.

…”

“…By replacing the scalar φ with iφ in the solution constructed in Ref [1], we obtain electrically-charged wormhole and black hole solutions in the Einstein-Maxwell-scalar theory, in which the scalar is a phantom field coupled to the Maxwell field non-minimally.…”

“…The theory and the solution can also be derived by a step-by-step generalization of the Ellis wormhole theory, presented in the Appendix A in Ref[1].…”

Trapping Horizons of the Evolving Charged Wormhole and Black Bounce

“…Despite the event horizon is the Killing horizon for a stationary black hole, it is hard to say where the horizon is just using the data in a particular moment. Especially for numerical relativity, researchers prefer the quasi-local concept, apparent horizon, as the boundary of a black hole [46][47][48]. Or one must use the information of the final state of the spacetime to determine the location of the event horizon.…”