arXiv subjects

Samantha Hergott

Publications and source records attributed to Samantha Hergott.

6 recordsLinked to original sources

arXiv2026

A rotating GUP black hole: metric, shadow, and bounds on quantum parameters

Recently, for the first time, a metric of a static spherically symmetric generalized uncertainty inspired quantum black hole was derived. We apply the modified Newman-Janis algorithm to this metric and derive its rotating counterpart. We show that this metric has all the correct limits, while due to Newman-Janis side effects, the singularity which was resolved in the static case, is introduced back into the model. However, the slowly-rotating limit of this black hole is singularity-free. Furthermore, we show that the presence of quantum parameters modifies the location of the horizons, temperature, and entropy of the black hole, and allows the existence of naked singularities even if the ratio of the spin parameter to mass of the black hole is less than unity. Finally, by computing the shadow parameters of this black hole and comparing them with data from the Event Horizon Telescope for both M87* and Sgr A*, we set bounds on one of the quantum parameters of the model, and show that there is a limit on the angular momentum of M87* if this model is valid.

gr-qc↗

arXiv2026

Dynamical model for black hole to white hole transitions

We present an asymptotically flat spherically symmetric non-singular metric that describes gravitational collapse and matter bounce with transient black hole and white hole regions. The metric provides a dynamical counterpart to proposed static non-singular black holes, and a phenomenological model for possible black hole to white hole transitions in quantum gravity.

gr-qc↗

arXiv2024

A generalized uncertainty-inspired quantum black hole

We derive the full spacetime metric of a generalized uncertainty-inspired quantum black hole. We examine a previous model of the interior in this approach and show that extending its metric to the full spacetime leads to serious issues in the asymptotic region. To remedy this, we introduce an ``improved scheme'' mimicking a similar prescription used in loop quantum gravity, where the quantum parameters are made momentum-dependent. Under this scheme, we rework the interior of the black hole and extend it to the full spacetime. We find that the resulting metric is asymptotically flat and its associated Kretschmann scalar is regular everywhere. We also show that the null expansion and Raychaudhuri equation are regular everywhere in this spacetime, implying that the classical singularity is resolved.

gr-qc↗

arXiv2022

Model metrics for quantum black hole evolution: Gravitational collapse, singularity resolution, and transient horizons

It is widely accepted that curvature singularity resolution should be a feature of quantum gravity. We present a class of time-dependent asymptotically flat spherically symmetric metrics that model gravitational collapse in quantum gravity. The metrics capture intuitions associated with the dynamics of singularity resolution, and horizon formation and evaporation following a matter bounce. A parameter in the metric associated with the speed of the bounce determines black hole lifetime as a power of its mass; this includes the Hawking evaporation time $M^{3}$.

gr-qc↗

arXiv2022

Effective black hole interior and the Raychadhuri equation

We show that loop quantum gravity effects leads to the finiteness of expansion and its rate of change in the effective regime in the interior of the Schwarzschild black hole. As a consequence the singularity is resolved. We find this in line with previous results about curvature scalar and strong curvature singularities in Kantowski-Sachs model which is isometric to Schwarzschild interior.

gr-qc↗

arXiv2021

Black hole singularity resolution via the modified Raychaudhuri equation in loop quantum gravity

We derive loop quantum gravity corrections to the Raychaudhuri equation in the interior of a Schwarzschild black hole and near the classical singularity. We show that the resulting effective equation implies defocusing of geodesics due to the appearance of repulsive terms. This prevents the formation of conjugate points, renders the singularity theorems inapplicable, and leads to the resolution of the singularity for this spacetime.

gr-qc↗