Sat - 07/24/21

Loop quantum deparametrized Schwarzschild interior and discrete black hole mass

  • Authors: Cong Zhang, Yongge Ma, Shupeng Song, Xiangdong Zhang
  • Subjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Theory (hep-th); Mathematical Physics (math-ph)
  • Arxiv link: https://arxiv.org/abs/2107.10579
  • Abstract We present the detailed analyses of a model of loop quantum Schwarzschild interior coupled to a massless scalar field and extend the results in our previous rapid communication \cite{zhang2020loop} to more general schemes. It is shown that the spectrum of the black hole mass is discrete and does not contain zero. This indicates the existence of a black hole remnant after Hawking evaporation due to loop quantum gravity effects. Besides to show the existence of a stable black hole remnant in the vacuum case, the quantum dynamics for the non-vacuum case is also solved and compared with the effective one.

There is no new related paper today

  1. [2107.10758] - Testing Kerr Black Hole Mimickers with Quasi-Periodic Oscillations from GRO J1655-40 - Xin Jiang, Peng Wang, Houwen Wu, Haitang Yang

Mon - 07/19/21

Effective Actions for Loop Quantum Cosmology in Fourth-Order Gravity

  • Authors: Marcello Miranda, Daniele Vernieri, Salvatore Capozziello, Francisco S. N. Lobo
  • Subjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Theory (hep-th)
  • Arxiv link: https://arxiv.org/abs/2107.07777
  • Abstract Loop Quantum Cosmology (LQC) is a theory which renders the Big Bang initial singularity into a quantum bounce, by means of short range repulsive quantum effects at the Planck scale. In this work, we are interested in reproducing the effective Friedmann equation of LQC, by considering a generic $f(R,P,Q)$ theory of gravity, where $R=g^{\mu\nu}R_{\mu\nu}$ is the Ricci scalar, $P=R_{\mu\nu}R^{\mu\nu}$, and $Q=R_{\alpha\beta\mu\nu}R^{\alpha\beta\mu\nu}$ is the Kretschmann scalar. An order reduction technique allows us to work in $f(R,P,Q)$ theories which are perturbatively close to General Relativity, and to deduce a modified Friedmann equation in the reduced theory. Requiring that the modified Friedmann equation mimics the effective Friedmann equation of LQC, we are able to derive several functional forms of $f(R,P,Q)$. We discuss the necessary conditions to obtain viable bouncing cosmologies for the proposed effective actions of $f(R,P,Q)$ theory of gravity.

Let Loop Quantum Gravity and Affine Quantum Gravity Examine Each Other

  • Authors: John R. Klauder
  • Subjects: General Relativity and Quantum Cosmology (gr-qc); Quantum Physics (quant-ph)
  • Arxiv link: https://arxiv.org/abs/2107.07879
  • Abstract Loop Quantum Gravity is widely developed using canonical quantization in an effort to find the correct quantization for gravity. Affine quantization, which is like canonical quantization augmented bounded in one orientation, e.g., a strictly positive coordinate. We open discussion using canonical and affine quantizations for two simple problems so each procedure can be understood. That analysis opens a modest treatment of quantum gravity gleaned from some typical features that exhibit the profound differences between aspects of seeking the quantum treatment of Einstein’s gravity.

There is no new related paper today

  1. [2107.07947] - Radiation from Einstein-Gauss-Bonnet de Sitter Black Hole via Tunneling Process - Sareh Eslamzadeh, Javad T. Firouzjaee, Kourosh Nozari

  2. [2107.07516] - Bootstrapping Quantum Extremal Surfaces I: The Area Operator - Alexandre Belin, Sean Colin-Ellerin

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