“Quasinormal Modes of Nonsingular Black Holes with Holonomy Corrections”

“Quasinormal Modes of Nonsingular Black Holes with Holonomy Corrections”

by | Apr 9, 2024 | GR & QC Articles

arXiv:2404.04447v1 Announce Type: new
Abstract: We calculate the quasinormal modes of a nonsingular spherically symmetric black hole effective model with holonomy corrections. The model is based on quantum corrections inspired by loop quantum gravity. It is covariant and results in a spacetime that is regular everywhere with a parameter-dependent black bounce.
Perturbations of these black holes due to massless scalar and electromagnetic fields have been previously calculated and some intriguing results were observed. For some modes, the frequency versus minimum-radius parameter trajectories were found to spiral and self-intersect in the complex plane. In addition, the spectrum of overtones has real frequencies that oscillate with increasing overtone number, and may even vanishing for some overtones.
We have calculated the quasinormal modes for all massless spin perturbations, including spin-1/2, and axial- and polar-gravitational. We find that the trajectory-spirals are restricted to scalar perturbations and observe some interesting overtone behaviour for gravitational perturbations. The amount of isospectrality violation in the gravitational quasinormal mode spectra is also examined.

Conclusions

The authors of the article have calculated the quasinormal modes of a nonsingular spherically symmetric black hole effective model with holonomy corrections. They have found some intriguing results for the perturbations of these black holes, including spiral and self-intersecting trajectories in the complex plane for some modes, oscillating frequencies for overtones, and isospectrality violation in the gravitational quasinormal mode spectra.

Future Roadmap

Challenges

  1. Further investigation is needed to understand the underlying mechanisms that lead to the observed trajectory-spirals and self-intersections in the complex plane. This may involve exploring the role of quantum corrections inspired by loop quantum gravity in shaping the behavior of the quasinormal modes.
  2. Understanding the physical implications and significance of the oscillating frequencies for overtones is another challenge that requires careful analysis. It is important to determine whether this behavior is a generic feature of the model or specific to certain perturbations.
  3. The examination of isospectrality violation in the gravitational quasinormal mode spectra requires more in-depth study. It is crucial to understand the implications of this violation and its potential consequences for black hole physics.

Opportunities

  • The observed trajectory-spirals and self-intersections in the complex plane for scalar perturbations open up new avenues for research. Investigating the implications of these unique features can provide insights into the behavior of black holes with holonomy corrections.
  • The oscillating frequencies for overtones present an opportunity to better understand the nature of these black holes and their response to perturbations. Exploring the connection between overtone behavior and the model parameters can shed light on the underlying physics.
  • Studying the isospectrality violation in the gravitational quasinormal mode spectra can provide valuable information about the limits and constraints of the model. This violation may indicate deviations from conventional black hole behavior and could potentially lead to new theoretical frameworks.

Roadmap

  1. Conduct further research to elucidate the origin and implications of the trajectory-spirals and self-intersections in the complex plane for scalar perturbations. Analyze the role of quantum corrections inspired by loop quantum gravity in shaping these features.
  2. Investigate the oscillating frequencies for overtones in more detail, exploring their dependence on model parameters and perturbation types. Determine if this behavior is generic or specific to certain perturbations.
  3. Deepen the examination of isospectrality violation in the gravitational quasinormal mode spectra, exploring its consequences for the black hole effective model with holonomy corrections and its implications for black hole physics.
  4. Explore potential extensions or modifications to the current model that could address the challenges and opportunities identified. Develop new theoretical frameworks to accommodate the observed phenomena and provide a comprehensive understanding of the nonsingular spherically symmetric black hole system.

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Title: Investigating Quasinormal Modes and Effective Potentials in Einstein-Scalar-Gauss-Bon

by | Dec 30, 2023 | GR & QC Articles

In this paper, we investigate quasinormal modes of scalar and electromagnetic
fields in the background of Einstein–scalar–Gauss–Bonnet (EsGB) black holes.
Using the scalar and electromagnetic field equations in the vicinity of the
EsGB black hole, we study nature of the effective potentials. The dependence of
real and imaginary parts of the fundamental quasinormal modes on parameter $p$
(which is related to the Gauss–Bonnet coupling parameter $alpha$) for
different values of multipole numbers $l$ are studied. We analyzed the effects
of massive scalar fields on the EsGB black hole, which tells us the existence
of quasi–resonances. In the eikonal regime, we find the analytical expression
for the quasinormal frequency and show that the correspondence between the
eikonal quasinormal modes and null geodesics is valid in the EsGB theory for
the test fields. Finally, we study grey-body factors of the electromagnetic
fields for different multipole numbers $l$, which deviates from Schwarzschild’s
black hole.

Conclusion:

  • The paper investigated the quasinormal modes of scalar and electromagnetic fields in the background of Einstein-scalar-Gauss-Bonnet (EsGB) black holes.
  • The study analyzed the effects of massive scalar fields on the EsGB black hole, revealing the existence of quasi-resonances.
  • In the eikonal regime, an analytical expression for the quasinormal frequency was derived, showing the validity of the correspondence between eikonal quasinormal modes and null geodesics in the EsGB theory for test fields.
  • The grey-body factors of the electromagnetic fields for different multipole numbers deviated from Schwarzschild’s black hole.

Future Roadmap

Potential Challenges:

  • Further investigation is needed to explore the nature of the effective potentials for both scalar and electromagnetic fields in the vicinity of EsGB black holes.
  • The dependence of the real and imaginary parts of the fundamental quasinormal modes on the parameter p (related to the Gauss-Bonnet coupling parameter α) should be further studied for a wider range of multipole numbers l.
  • More research is required to fully understand the effects of massive scalar fields on the EsGB black hole and its implications for quasi-resonances.
  • Validation and verification of the analytical expression for the quasinormal frequency in the eikonal regime using experimental or observational data is necessary to establish its practicality.
  • Further exploration is needed to understand the deviation of grey-body factors of electromagnetic fields in EsGB black holes compared to Schwarzschild’s black hole, and its potential implications.

Opportunities on the Horizon:

  • This research opens up opportunities for studying complex physics phenomena in EsGB black holes and their implications for the nature of gravitational waves and singularities.
  • In-depth understanding of the effects of massive scalar fields on EsGB black holes and the existence of quasi-resonances can contribute to advancements in theoretical physics and astrophysics.
  • The analytical expression for the quasinormal frequency in the eikonal regime and its validation could provide a valuable tool for future research in black hole physics.
  • The exploration of deviations in grey-body factors of electromagnetic fields in EsGB black holes can lead to new insights into the behavior of matter and radiation near these exotic objects.

Overall, this research paves the way for further investigation into the properties and behaviors of EsGB black holes, presenting both challenges and opportunities for advancements in theoretical physics and astrophysics.

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