Generalized Extended Uncertainty Principle Black Holes: Shadow and lensing in the macro- and microscopic realms

• Published in: arXiv.org 2023-12
• Main Authors: Nikko John Leo S Lobos, Pantig, Reggie C
• Format: Article
• Language: English
• Subjects: Deflection; Deviation; Principles; Shadows; Uncertainty principles
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.2208.00618

Motivated by the recent work about the Extended Uncertainty Principle (EUP) black holes \cite{Mureika:2018gxl}, we present in this study its extension called the Generalized Extended Uncertainty Principle (GEUP) black holes. In particular, we investigated the GEUP effects on astrophysical and micro-black holes. First, we derive the expression for the shadow radius to investigate its behavior as perceived by a static observer located near and far from the black hole. Constraints to the large fundamental length scale \(L*\) up to \(2\sigma\) level were also found using the EHT data: for Sgr. A*, \(L* = 5.716\text{x}10^{10}\) m, while for M87*, \(L* = 3.264\text{x}10^{13}\) m. Under the GEUP effect, the value of the shadow radius behaves the same way as the Schwarzschild case due to a static observer, and the effect only emerges if the mass of the black hole \(M\) is around the order of magnitude of \(L_*\) (or \(l_\text{Pl}\)). In addition, the GEUP effect increases the shadow radius for astrophysical black holes, but the reverse happens for micro-black holes. We also explored GEUP effects to the weak and strong deflection angles as an alternative analysis. For both realms, a time-like particle gives a higher value for the weak deflection angle. Similar to the shadow, the deviation is seen when the values of \(L_*\) and \(M\) are close. The strong deflection angle gives more sensitivity to GEUP deviation at smaller masses in the astrophysical scenario. However, the weak deflection angle is a better probe in the micro world.