Fri - 12/08/23

Shadows of Loop Quantum Black Holes: Semi-analytical Simulations of Loop Quantum Gravity Effects on Sagittarius A* and M 87*

  • Authors: Hong-Xuan Jiang, Cheng Liu, Indu K. Dihingia, Yosuke Mizuno, Haiguang Xu, Tao Zhu, Qiang Wu
  • Subjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Astrophysical Phenomena (astro-ph.HE)
  • Arxiv link: https://arxiv.org/abs/2312.04288
  • Abstract In this study, we delve into the observational implications of rotating Loop Quantum Black Holes (LQBHs) within an astrophysical framework. We employ semi-analytical General Relativistic Radiative Transfer (GRRT) computations to study the emission from the accretion flow around LQBHs. Our findings indicate that the increase of Loop Quantum Gravity (LQG) effects results in an enlargement of the rings from LQBHs, thereby causing a more circular polarization pattern in the shadow images. We make comparisons with the Event Horizon Telescope (EHT) observations of Sgr\,A$^$ and M\,87$^$, which enable us to determine an upper limit for the polymetric function $P$ in LQG. The upper limit for Sgr\,A$^$ is $0.2$, while for M\,87$^$ it is $0.07$. Both black holes exhibit a preference for a relatively high spin ($a\gtrsim0.5$ for Sgr\,A$^$ and $0.5\lesssim a \lesssim 0.7$ for M\,87$^$). The constraints for Sgr\,A$^$ are based on black hole spin and ring diameter, whereas for M\,87$^$, the constraints are further tightened by the polarimetric pattern. In essence, our simulations provide observational constraints on the effect of LQG in supermassive black holes (SMBH), providing the most consistent comparison with observation.

There is no new related paper today

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  2. [2312.03811] - Quantum reference frames, revisited - Matthew J. Lake, Marek Miller

  3. [2312.04301] - The appearance of the regular black hole with a stable Cauchy horizon - Li-Ming Cao, Long-Yue Li, Xia-Yuan Liu, Yu-Sen Zhou

  4. [2312.03831] - Robustness of the derivative expansion in Asymptotic Safety - Alessio Baldazzi, Kevin Falls, Yannick Kluth, Benjamin Knorr

Thu - 12/07/23

There is no new related paper today

There is no new related paper today

  1. [2312.03332] - Geometry from D-branes in Nonrelativistic String Theory - Alberto Guijosa, Igmar C. Rosas-López

Wed - 12/06/23

Primordial fluctuations from quantum gravity: 16-cell topological model

  • Authors: Pietropaolo Frisoni, Francesco Gozzini, Francesca Vidotto
  • Subjects: General Relativity and Quantum Cosmology (gr-qc)
  • Arxiv link: https://arxiv.org/abs/2312.02399
  • Abstract We present a numerical analysis of an Hartle-Hawking state for the early universe, in the deep quantum regime, computed using the covariant Loop Quantum Gravity formalism, in a truncation defined by 16-cell and in a simplified case where the dynamics is defined by SU(2) BF theory. We compute mean geometry, fluctuations and correlations. The results are consistent with the hypothesis that refining the triangulation does not affect the global physical picture substantially.

Primordial fluctuations from quantum gravity: 16-cell topological model

  • Authors: Pietropaolo Frisoni, Francesco Gozzini, Francesca Vidotto
  • Subjects: General Relativity and Quantum Cosmology (gr-qc)
  • Arxiv link: https://arxiv.org/abs/2312.02399
  • Abstract We present a numerical analysis of an Hartle-Hawking state for the early universe, in the deep quantum regime, computed using the covariant Loop Quantum Gravity formalism, in a truncation defined by 16-cell and in a simplified case where the dynamics is defined by SU(2) BF theory. We compute mean geometry, fluctuations and correlations. The results are consistent with the hypothesis that refining the triangulation does not affect the global physical picture substantially.
  1. [2312.02234] - Testing regularity of black holes with X-rays and Gravitational Waves - Swarnim Shashank

Tue - 12/05/23

Quantum Schwarzschild geometry in effective-field-theory models of gravity

  • Authors: Emmanuele Battista
  • Subjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Theory (hep-th)
  • Arxiv link: https://arxiv.org/abs/2312.00450
  • Abstract The Schwarzschild geometry is investigated within the context of effective-field-theory models of gravity. Starting from its harmonic-coordinate expression, we derive the metric in standard coordinates by keeping the leading one-loop quantum contributions in their most general form. We examine the metric horizons and the nature of the hypersurfaces having constant radius; furthermore, a possible energy-extraction process which violates the null energy condition is described, and both timelike and null geodesics are studied. Our analysis shows that there is no choice of the sign of the constant parameter embodying the quantum correction to the metric which leaves all the features of the classical Schwarzschild solution almost unaffected.

There is no new related paper today

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  2. [2312.00618] - Future of Bianchi I magnetic cosmologies with kinetic matter - Ho Lee, Ernesto Nungesser

  3. [2312.00120] - Persistence of the Pattern in the Interior of 5d Moduli Spaces - Tom Rudelius

  4. [2312.00603] - Behaviour of n-point scattering amplitudes at high energies - Shreya Shrivastava

Mon - 12/04/23

Quantum Schwarzschild geometry in effective-field-theory models of gravity

  • Authors: Emmanuele Battista
  • Subjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Theory (hep-th)
  • Arxiv link: https://arxiv.org/abs/2312.00450
  • Abstract The Schwarzschild geometry is investigated within the context of effective-field-theory models of gravity. Starting from its harmonic-coordinate expression, we derive the metric in standard coordinates by keeping the leading one-loop quantum contributions in their most general form. We examine the metric horizons and the nature of the hypersurfaces having constant radius; furthermore, a possible energy-extraction process which violates the null energy condition is described, and both timelike and null geodesics are studied. Our analysis shows that there is no choice of the sign of the constant parameter embodying the quantum correction to the metric which leaves all the features of the classical Schwarzschild solution almost unaffected.

There is no new related paper today

  1. [2312.00409] - White Paper and Roadmap for Quantum Gravity Phenomenology in the Multi-Messenger Era - R. Alves Batista, G. Amelino-Camelia, D. Boncioli, J. M. Carmona, A. di Matteo, G. Gubitosi, I. Lobo, N. E. Mavromatos, C. Pfeifer, D. Rubiera-Garcia, E. N. Saridakis, T. Terzić, E. C. Vagenas, P. Vargas Moniz, H. Abdalla, M. Adamo, F. K. Anagnostopoulos, V. Antonelli, M. Asorey, A. Ballesteros, D. Benisty, M. Boettcher, J. Bolmont, A. Bonilla, P. Bosso, M. Bouhmadi-López, L. Burderi, A. Campoy-Ordaz, S. Caroff, S. Cerci, J. L. Cortes, V. D’Esposito, S. Das, M. de Cesare, M. Demirci, F. Di Lodovico, T. Di Salvo, J. M. Diego, G. Djordjevic, A. Domi, L. Ducobu, C. Escamilla-Rivera, G. Fabiano, D. Fernández-Silvestre, S. A. Franchino-Viñas, A. M. Frassino, D. Frattulillo, L. J. Garay, M. Gaug, L. Á. Gergely, E. I. Guendelman, D. Guetta, I. Gutierrez-Sagredo, P. He, et al. (49 additional authors not shown)

  2. [2312.00618] - Future of Bianchi I magnetic cosmologies with kinetic matter - Ho Lee, Ernesto Nungesser

  3. [2312.00120] - Persistence of the Pattern in the Interior of 5d Moduli Spaces - Tom Rudelius

  4. [2312.00603] - Behaviour of n-point scattering amplitudes at high energies - Shreya Shrivastava

New papers last week