Published April 19, 2026
| Version v1
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A Smooth 5D Braneworld Black Hole Model with a Horizon Brane-Bulk Transition Mechanism
Description
We propose a speculative 5D braneworld black hole model in which the observable 3 + 1-
dimensional universe is represented as a brane embedded in a higher-dimensional bulk space
time. Within this framework, we construct a smooth, horizon-regular warped metric with
two tunable dimensionless parameters: a brane-bulk coupling parameter γ and a bulk parity
breaking parameter α. The model is designed so that, for non-zero parameter values, the
near-horizon region can support nontrivial bulk-directed evolution for causal geodesics that
originate on the brane, while the classical Schwarzschild singularity is regularized within
the model geometry. In the far-field limit, the induced brane metric recovers standard
Schwarzschild behavior asymptotically. We emphasize that this work does not establish that
astrophysical black holes are inter-dimensional portals, nor does it claim a universal theo
rem about gravity. Rather, it formulates a falsifiable hypothesis within higher-dimensional
gravity and braneworld geometry, with potentially testable observational consequences for
black hole shadows and gravitational-wave signals.