Black holes in depleted Dehnen dark matter halos with physical inner edges and strong-field observables
Abstract
We construct a static and spherically symmetric black hole (BH) spacetime surrounded by a depleted Dehnen dark matter (DM) halo. The model describes a final equilibrium configuration rather than dynamical accretion process: the initial halo mass inside a prescribed inner edge is incorporated into the central BH, leaving a vacuum gap between the dressed horizon and the surviving halo. Consequently, the horizon radius depends on the Dehnen cusp index γ and the absorbed halo mass, while the Schwarzschild result is recovered exactly when the halo is removed. We derive general expressions for the metric functions and redshift phase and obtain explicit solutions for γ=0,1,2, and 5/2. The dominant energy condition imposes the universal local bound κ≥5/4, whereas global admissibility depends additionally on the cusp index and halo compactness. A literal stable Einstein-cluster interpretation requires the stronger condition κ≥3 when stable circular motion is imposed at the halo edge. We also analyze the photon sphere, shadow, and admissible parameter space, demonstrating how the halo cusp and depletion scale affect strong-field observables. Previously studied analytic BH--halo geometries and the Schwarzschild and weak-halo limits follow as special cases of the general construction.
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BibTeX
@misc{hassanabadi2026black,
title = {{Black holes in depleted Dehnen dark matter halos with physical inner edges and strong-field observables}},
author = {Hassan Hassanabadi and Soroush Zare},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.23750},
eprint = {2609.23750},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.23750},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Black holes in depleted Dehnen dark matter halos with physical inner edges and strong-field observables
AU - Hassan Hassanabadi
AU - Soroush Zare
PY - 2026
DA - 2026/09/20
PB - arXiv
DO - 10.48550/arxiv.2609.23750
UR - https://arxiv.org/abs/2609.23750
AB - We construct a static and spherically symmetric black hole (BH) spacetime surrounded by a depleted Dehnen dark matter (DM) halo. The model describes a final equilibrium configuration rather than dynamical accretion process: the initial halo mass inside a prescribed inner edge is incorporated into the central BH, leaving a vacuum gap between the dressed horizon and the surviving halo. Consequently, the horizon radius depends on the Dehnen cusp index γ and the absorbed halo mass, while the Schwarzschild result is recovered exactly when the halo is removed. We derive general expressions for the metric functions and redshift phase and obtain explicit solutions for γ=0,1,2, and 5/2. The dominant energy condition imposes the universal local bound κ≥5/4, whereas global admissibility depends additionally on the cusp index and halo compactness. A literal stable Einstein-cluster interpretation requires the stronger condition κ≥3 when stable circular motion is imposed at the halo edge. We also analyze the photon sphere, shadow, and admissible parameter space, demonstrating how the halo cusp and depletion scale affect strong-field observables. Previously studied analytic BH--halo geometries and the Schwarzschild and weak-halo limits follow as special cases of the general construction.
ER -