Revisiting Schwarzschild black hole singularity through string theory

In this letter, we derive the singular condition for black holes and demonstrate the potential resolution of the Schwarzschild black hole singularity in general relativity using non-perturbative ${\alpha }^{\mathrm{\prime }}$ corrections of string theory. This work is motivated by the Belinskii, Khalatnikov and Lifshitz (BKL) proposal, which suggests that the structure of the black hole interior in vacuum Einstein’s equations can be transformed into the Kasner universe near the singularity. This transformation allows for the description of the black hole interior using the $O(d,d)$ invariant anisotropic Hohm-Zwiebach action, which includes all orders of ${\alpha }^{\mathrm{\prime }}$ corrections.