2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/207067Progress in numerical relativity has been hindered for 30 years because of the difficulties of avoiding spacetime singularities in numerical evolution. We propose a scheme which excises a region inside an apparent horizon containing the singularity. Two major ingredients of the scheme are the use of a horizon-locking coordinate and a finite differencing which respects the causal structure of the spacetime. Encouraging results of the scheme in the spherical collapse case are given.9 pagesGeneral Relativity and Quantum Cosmologytext