Fri - 11/01/24

**Title:

      Quantum dust collapse with cosmological constant and methods for constructing conformal diagrams**  - **Authors:** Michał Bobula, Tomasz Pawłowski  - **Subjects:** Subjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Theory (hep-th)  - **Arxiv link:** [https://arxiv.org/abs/](https://arxiv.org/abs/)  - **Abstract**  The loop quantum gravitational collapse of the dust ball in presence of positive cosmological constant is investigated within the Oppenheimer-Snyder collapse scenario. The dust ball interior is described within the framework of loop quantum cosmology, while its exterior geometry is determined by the differentiability of the spacetime metric at the dust ball surface and the assumption of the (vacuum) exterior to be stationary. In order to determine the global causal structure of the investigated spacetime a robust (numerical) method of constructing Penrose-Carter diagrams is built. Unfortunately the presence of cosmological constant does not cure the problems already present in the case of it vanishing -- the exterior geometry resembles that of Reissner-Nordström-de Sitter black hole, in particular featuring timelike singularties.

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Thu - 10/31/24

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There is no new related paper today

  1. [] - Title: Nonsingular black holes as dark matter - Paul C. W. Davies, Damien A. Easson, Phillip B. Levin

Wed - 10/30/24

**Title:

      Formation of nonsingular spherical black holes with holonomy corrections**  - **Authors:** Asier Alonso-Bardaji  - **Subjects:** Subjects: General Relativity and Quantum Cosmology (gr-qc)  - **Arxiv link:** [https://arxiv.org/abs/](https://arxiv.org/abs/)  - **Abstract**  We present a canonical model of spherical gravity with covariant corrections motivated by loop quantum gravity. The effective Hamiltonian defines univocally a family of geometries that generalizes the Lemaître-Tolman-Bondi spacetimes, and they can be matched to the vacuum of the theory across a timelike hypersurface comoving with the flow of matter. Such is precisely the complete spacetime picture of a spherical star subject to its own gravitational pull. The singularity gets replaced with a spacelike boundary in the trapped region of spacetime, where the curvature remains finite, and the area of the orbits of the spherical symmetry group attains its infimum. Observers falling into the black hole are doomed to travel forever towards this boundary without ever reaching it. The theory also predicts the formation of stable black-hole remnants of Planckian mass.

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Tue - 10/29/24

There is no new related paper today

There is no new related paper today

  1. [] - Title: Charged superradiant instability in a spherical symmetric regular black hole - Yizhi Zhan, Hengyu Xu, Shao-Jun Zhang

Mon - 10/28/24

There is no new related paper today

There is no new related paper today

  1. [] - Title: Charged superradiant instability in a spherical symmetric regular black hole - Yizhi Zhan, Hengyu Xu, Shao-Jun Zhang

New papers last week