Fri - 05/10/24

There is no new related paper today

There is no new related paper today

Thu - 05/09/24

There is no new related paper today

There is no new related paper today

  1. [] - Title: Thermodynamics and geometrothermodynamics of regular black holes - H. Quevedo, M.N. Quevedo, A. Sanchez

Wed - 05/08/24

**Title:

      Emergent gravity from the correlation of spin-$\tfrac{1}{2}$ systems coupled with a scalar field**  - **Authors:** Quentin Ansel  - **Subjects:** Subjects: General Relativity and Quantum Cosmology (gr-qc); Quantum Physics (quant-ph)  - **Arxiv link:** [https://arxiv.org/abs/](https://arxiv.org/abs/)  - **Abstract**  This paper introduces several ideas of emergent gravity, which come from a system similar to an ensemble of quantum spin-$\tfrac{1}{2}$ particles. To derive a physically relevant theory, the model is constructed by quantizing a scalar field in curved space-time. The quantization is based on a classical discretization of the system, but contrary to famous approaches, like loop quantum gravity or causal triangulation, a Monte-Carlo based approach is used instead of a simplicial approximation of the space-time manifold. This avoids conceptual issues related to the choice of the lattice. Moreover, this allows us to easily encode the geometric structures of space, given by the geodesic length between points, into the mean value of a correlation operator between two spin-like systems. Numerical investigations show the relevance of the approach, and the presence of two regimes: a classical and a quantum regime. The latter is obtained when the density of points reaches a given threshold. Finally, a multi-scale analysis is given, where the classical model is recovered from the full quantum one. Each step of the classical limit is illustrated with numerical computations, showing the very good convergence towards the classical limit and the computational efficiency of the theory.

There is no new related paper today

Tue - 05/07/24

Emergent gravity from the correlation of spin-$\tfrac{1}{2}$ systems coupled with a scalar field

  • Authors: Quentin Ansel
  • Subjects: General Relativity and Quantum Cosmology (gr-qc); Quantum Physics (quant-ph)
  • Arxiv link: https://arxiv.org/abs/2405.02380
  • Abstract This paper introduces several ideas of emergent gravity, which come from a system similar to an ensemble of quantum spin-$\tfrac{1}{2}$ particles. To derive a physically relevant theory, the model is constructed by quantizing a scalar field in curved space-time. The quantization is based on a classical discretization of the system, but contrary to famous approaches, like loop quantum gravity or causal triangulation, a Monte-Carlo based approach is used instead of a simplicial approximation of the space-time manifold. This avoids conceptual issues related to the choice of the lattice. Moreover, this allows us to easily encode the geometric structures of space, given by the geodesic length between points, into the mean value of a correlation operator between two spin-like systems. Numerical investigations show the relevance of the approach, and the presence of two regimes: a classical and a quantum regime. The latter is obtained when the density of points reaches a given threshold. Finally, a multi-scale analysis is given, where the classical model is recovered from the full quantum one. Each step of the classical limit is illustrated with numerical computations, showing the very good convergence towards the classical limit and the computational efficiency of the theory.

Cosmological sector of Loop Quantum Gravity: a Yang-Mills approach

  • Authors: Matteo Bruno
  • Subjects: General Relativity and Quantum Cosmology (gr-qc); Mathematical Physics (math-ph)
  • Arxiv link: https://arxiv.org/abs/2405.03019
  • Abstract In this manuscript, we address the issue of the loss of SU(2) internal symmetry in Loop Quantum Cosmology and its relationship with Loop Quantum Gravity. Drawing inspiration from Yang-Mills theory and employing the framework of fiber bundle theory, we successfully identify a cosmological sector for General Relativity in Ashtekar variables, which preserves the SU(2) structure of the theory and the diffeomorphism gauge symmetry. Additionally, we proceed to quantize it using the machinery of Loop Quantum Gravity, uncovering that the resulting spin-network states exhibit distinctive symmetry properties and encompass the usual states of Loop Quantum Cosmology.

There is no new related paper today

  1. [2405.03554] - Regular black holes and their relationship to polymerized models and mimetic gravity - Kristina Giesel, Hongguang Liu, Parampreet Singh, Stefan Andreas Weigl

Mon - 05/06/24

There is no new related paper today

There is no new related paper today

  1. [2405.01773] - “Observables” in de Sitter Quantum Gravity: in Perturbation Theory and Beyond - Tom Banks (NHETC and Department of Physics and Astronomy, Rutgers University)

  2. [2405.02227] - Comparing the decoherence effects due to black holes versus ordinary matter - Anna Biggs, Juan Maldacena

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