Annihilation-to-nothing: DeWitt boundary condition inside a black hole Suddhasattwa Brahma, Che-Yu Chen and Dong-han Yeom Eur. Phys. J. C, 82 9 (2022) 772 Published online: 01 September 2022 DOI: 10.1140/epjc/s10052-022-10730-1