English

Effective loop quantum gravity framework for vacuum spherically symmetric space-times

General Relativity and Quantum Cosmology 2022-06-15 v3

Abstract

We develop an effective framework for the μˉ\bar\mu scheme of holonomy corrections motivated by loop quantum gravity for vacuum spherically symmetric space-times. This is done by imposing the areal gauge in the classical theory, and then expressing the remaining components of the Ashtekar-Barbero connection in the Hamiltonian constraint in terms of holonomies of physical length Pl\ell_{\rm Pl}. The stationary solutions to the effective Hamiltonian constraint can be found exactly, and we give the explicit form of the effective metric in Painlev\'e-Gullstrand coordinates. This solution has the correct classical limit, the quantum gravity corrections decay rapidly at large distances, and curvature scalars are bounded by the Planck scale, independently of the black hole mass MM. In addition, the solution is valid for radii xxmin(Pl2M)1/3x \ge x_{\rm min} \sim (\ell_{\rm Pl}^2 M)^{1/3} indicating the need for a matter field, with an energy density bounded by the Planck scale, to provide a source for the curvature in the space-time. Finally, for MmPlM \gg m_{\rm Pl}, the space-time has an outer and also an inner horizon, within which the expansion for outgoing radial null geodesics becomes positive again. On the other hand, for sufficiently small MmPlM \sim m_{\rm Pl}, there are no horizons at all in the effective metric.

Keywords

Cite

@article{arxiv.2006.09302,
  title  = {Effective loop quantum gravity framework for vacuum spherically symmetric space-times},
  author = {Jarod George Kelly and Robert Santacruz and Edward Wilson-Ewing},
  journal= {arXiv preprint arXiv:2006.09302},
  year   = {2022}
}

Comments

24 pages, 5 figures. v2: Minor changes; v3: typos corrected

R2 v1 2026-06-23T16:22:47.987Z