Weak Gravity Conjecture Validation with Photon Spheres of Quantum Corrected AdS-Reissner-Nordstrom Black Holes in Kiselev Spacetime

TL;DR

The paper addresses whether the Weak Gravity Conjecture (WGC) holds for quantum-corrected charged AdS black holes embedded in Kiselev spacetime. It combines quantum corrections (via a parameter a) with a surrounding quintessence-like fluid and analyzes photon-sphere topology through a two-dimensional effective potential, linking horizon structure to extremality and the WGC. The authors find that, for several parameter choices (e.g., omega values around minus one third and minus one), the WGC is upheld and photon spheres exhibit a negative unit topological charge, while for omega equal to minus four thirds the photon sphere may vanish, signaling a WGC violation in that regime; WCCC compatibility is discussed across the explored space. Overall, the work supports the universality of the WGC under quantum corrections in a nontrivial spacetime background and highlights the utility of topological photon-sphere diagnostics for probing quantum-gravity conjectures, with implications for future theoretical and observational studies.

Abstract

In this study, we investigate the Weak Gravity Conjecture (WGC) in the context of quantum-corrected AdS-Reissner-Nordstrom (AdS-RN) black holes within Kiselev spacetime. Our focus is on photon spheres, which serve as markers for stable and unstable photon spheres. We confirm the validity of the WGC by demonstrating that quantum corrections do not alter the essential charge-to-mass ratio, thereby supporting the conjecture's universality. Our analysis reveals that black holes with a charge greater than their mass ($Q > M$) possess photon spheres or exhibit a total topological charge of the photon sphere (PS = -1), which upholds the WGC. This finding is significant as it reinforces the conjecture's applicability even in the presence of quantum corrections. Furthermore, we examine various parameter configurations to understand their impact on the WGC. Specifically, we find that configurations with $ω= -\frac{1}{3}$ and $ω= -1$ maintain the conjecture, indicating that these values do not disrupt the charge-to-mass ratio required by the WGC. However, for $ω= -\frac{4}{3}$, the conjecture does not hold, suggesting that this particular parameter value leads to deviations from the expected behavior. These results open new directions for research in quantum gravity, as they highlight the importance of specific parameter values in maintaining the WGC. The findings suggest that while the WGC is robust under certain conditions, there are scenarios where it may be challenged, prompting further investigation into the underlying principles of quantum gravity

Figures (6)

• Figure 1: The plot of $f(r)-r$ for quantum-corrected (AdS-RN) black holes in Kiselev spacetime with respect to free parameters
• Figure 2: The plot of photon spheres with respect to $c = 0, \ell = 1, a = 0.4$ for $M>Q$ in Fig. (\ref{['2a']}), M=Q in Fig. (\ref{['2b']}) and $Q>M$ in Fig. (\ref{['2c']})
• Figure 3: The plot of photon spheres with respect to $\ell = 1, a = 0.1, c = 0.2, \omega = 0$ for $M>Q$ in Fig. (\ref{['3a']}), M=Q in Fig. (\ref{['3b']}) and $Q>M$ in Fig. (\ref{['3c']}) and with respect to $\ell = 1, a = 0.4, c = 0.2, \omega = 0$ for $Q>M$ in Fig. (\ref{['3d']})
• Figure 4: The plot of photon spheres with respect to $\ell = 1, a = 0.1, c = 0.2, \omega = -2/3$ for $M>Q$ in Fig. (\ref{['4a']}), M=Q in Fig. (\ref{['4b']}) and $Q>M$ in Fig. (\ref{['4c']})
• Figure 5: The plot of photon spheres with respect to $\ell = 1, a = 0.4, c = 0.2, \omega = -1/3$ for $Q>M$ in Fig. (\ref{['5a']}) and with respect to $\ell = 1, a = 0.1, c = 0.7, \omega = -1/3$ for $Q>M$ in Fig. (\ref{['5b']})