Recent observational data from the Event Horizon Telescope (EHT)
collaboration provide convincing realistic evidence for the existence of black
hole rotation. From a phenomenological perspective, a recently proposed stable
rotating regular (SRR) black hole circumvents the theoretical flaws of the Kerr
solution. For the purpose of obtaining observational signatures of this black
hole, we study its gravitational lensing effect. In the strong field limit, we
calculate the deflection angle of light, the radius of the photon sphere, and
other observables. The observables include the relativistic image position,
separation, magnification, and time delays between different images. Then, by
modeling M87* and Sgr A* as the SRR black hole, we compute their observables
and evaluate the deviation of the observables from the Kerr case. In the weak
field limit, we calculate the light deflection angle of M87* and Sgr A* via the
Gauss-Bonnet theorem (GBT). With the growth of deviation parameter $e$, the
gravitational lensing effect in the weak field limit intensifies monotonically,
and the gravitational lensing effect in the strong field limit changes
dramatically only at high spins. Our research may contribute to distinguish
between SRR black holes from Kerr black holes under higher-precision
astronomical observations.
Future Roadmap:
Introduction
In recent years, the Event Horizon Telescope (EHT) collaboration has provided compelling evidence for the existence of black hole rotation. However, a new stable rotating regular (SRR) black hole has been proposed to overcome some theoretical flaws of the previous Kerr solution. This article aims to explore the gravitational lensing effects of the SRR black hole and differentiate it from the Kerr case.
Observables and Calculations
The study focuses on several observables that can be used to distinguish between the SRR black hole and the Kerr black hole. These observables include:
- Relativistic image position
- Separation between images
- Magnification of images
- Time delays between images
To calculate these observables, the deflection angle of light, the radius of the photon sphere, and other factors need to be determined in both the weak field limit and the strong field limit. In the weak field limit, the Gauss-Bonnet theorem (GBT) is used for light deflection angle calculations for M87* and Sgr A*.
Deviation Parameter and Gravitational Lensing
The article explains that the intensity of the gravitational lensing effect in the weak field limit increases with the growth of the deviation parameter $e$. On the other hand, in the strong field limit, significant changes in the gravitational lensing effect are only observed at high spins. This information can aid in distinguishing SRR black holes from Kerr black holes under higher-precision astronomical observations.
Conclusion
This research on the gravitational lensing effects of stable rotating regular black holes provides a potential method for differentiating them from previous Kerr black holes. By calculating various observables, including relativistic image positions, separations, magnifications, and time delays, it is possible to evaluate the deviation of the observables from the Kerr case. However, further astronomical observations and higher precision measurements are required to fully understand and confirm these distinctions.
Potential Challenges and Opportunities:
The road ahead presents some challenges and opportunities:
- Challenge: Obtaining higher-precision observations: Accurate measurements and observations will be crucial to identify the differences between SRR black holes and Kerr black holes.
- Challenge: Theoretical validation: The proposed SRR black hole must undergo further theoretical scrutiny to confirm its stability and resolve any potential flaws.
- Opportunity: Advancements in observational techniques: Technological advancements in observational tools and telescopes may enable researchers to obtain the necessary data to distinguish between these two types of black holes.
- Opportunity: New insights into black hole physics: Understanding the nature and characteristics of SRR black holes could provide new insights into the behavior of rotating black holes and the fundamental principles of general relativity.
With continued progress in observational capabilities and theoretical investigations, future studies can build upon this research to enhance our understanding of black hole rotation and potentially revolutionize our knowledge of astrophysics.