Fri - 12/06/24

There is no new related paper today

There is no new related paper today

  1. [] - Title: Regular black holes from thin-shell collapse - Pablo Bueno, Pablo A. Cano, Robie A. Hennigar, Ángel J. Murcia

Thu - 12/05/24

**Title:

      Low-curvature quantum corrections from unitary evolution of de Sitter space**  - **Authors:** Steffen Gielen, Rita B. Neves  - **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**  We study the quantum dynamics of de Sitter space formulated as a minisuperspace model with flat spatial hypersurfaces in unimodular gravity, both in the Wheeler-DeWitt approach and in loop quantum cosmology (LQC). Time evolution is defined naturally in unimodular time, which appears as conjugate to the cosmological (integration) constant. We show that requiring unitary time evolution "resolves" the de Sitter horizon where the flat slicing breaks down and leads to strong quantum effects there, even though locally nothing special happens at this surface. For a cosmological constant that is far below the Planck scale, loop quantum gravity corrections do not alter the main results in any substantial way. This model illustrates the fundamental clash between general covariance and unitarity in quantum gravity.

There is no new related paper today

Wed - 12/04/24

**Title:

      Quantum-reduced loop gravity: New perspectives on the kinematics and dynamics**  - **Authors:** Ilkka Mäkinen  - **Subjects:** Subjects: General Relativity and Quantum Cosmology (gr-qc)  - **Arxiv link:** [https://arxiv.org/abs/](https://arxiv.org/abs/)  - **Abstract**  We present a systematic approach to the kinematics of quantum-reduced loop gravity, a model originally proposed by Alesci and Cianfrani as an attempt to probe the physical implications of loop quantum gravity. We implement the quantum gauge-fixing procedure underlying quantum-reduced loop gravity by introducing a master constraint operator on the kinematical Hilbert space of loop quantum gravity, representing a set of gauge conditions which classically constrain the densitized triad to be diagonal. The standard Hilbert space of quantum-reduced loop gravity can be recovered as a space of solutions of the master constraint operator, while on the other hand the master constraint approach provides a useful starting point for considering possible generalizations of the standard construction. We also examine the quantum dynamics of states consisting of a single six-valent node in the quantum-reduced framework. We find that the Hamiltonian which governs the dynamics of such states bears a close formal resemblance to the Hamiltonian constraint of Bianchi I models in loop quantum cosmology.

There is no new related paper today

  1. [] - Title: Spacetime-curvature induced uncertainty principle: linking the large-structure global effects to the local black hole physics - Reggie C. Pantig, Gaetano Lambiase, Ali Övgün, Nikko John Leo S. Lobos

Tue - 12/03/24

**Title:

      Deformed algebraic structure of angular momenta: GUP perspective**  - **Authors:** Gaurav Bhandari, S. D. Pathak, Manabendra Sharma, Anzhong Wang  - **Subjects:** Subjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Theory (hep-th); Mathematical Physics (math-ph); Quantum Physics (quant-ph)  - **Arxiv link:** [https://arxiv.org/abs/](https://arxiv.org/abs/)  - **Abstract**  The prediction of a minimal length scale by various quantum gravity candidates (such as string/M theory, Doubly Special Relativity, Loop Quantum Gravity and others) have suggested modification of Heisenberg Uncertainty Principle (HUP), resulting in the Generalized Uncertainty Principle (GUP). In this short review, we investigate the origins of the GUP and examine higher-order models, focusing on the linear plus quadratic form of the GUP. We extend the concept of minimal length to minimal angular resolution, which plays a crucial role in modifying angular momentum and its associated algebra. A comparison is made between the standard angular momentum commutator algebra and that modified by the GUP. Finally, we review its application in the hydrogen atom spectra and and discuss future endeavors.

There is no new related paper today

  1. [] - Title: Regular black holes from Kiselev anisotropic fluid - Luis C. N. Santos

Mon - 12/02/24

**Title:

      Black hole tunneling in loop quantum gravity**  - **Authors:** Hongwei Tan, Rong-Zhen Guo, Jingyi Zhang  - **Subjects:** Subjects: General Relativity and Quantum Cosmology (gr-qc)  - **Arxiv link:** [https://arxiv.org/abs/](https://arxiv.org/abs/)  - **Abstract**  In this paper, we investigate the Hawking radiation of the quantum Oppenheimer- Snyde black hole with the tunneling scheme by Parikh and Wilczek. We calculate the emission rate of massless scalar particles. Compared to the traditional results within the framework of General Relativity, our findings include quantum correction terms arising from loop quantum gravity effects. Following the approach in [1, 2], we establish the entropy of the black hole. This entropy includes a logarithmic correction, which arises from quantum gravity effects. Our result is consistent with the well-known result in the context of quantum gravity.

There is no new related paper today

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