On the existence of \(n\)-geodesically complete or future complete solutions of Einstein's field equations with smooth asymptotic structure (Q1112353)

It is demonstrated that initial data sufficiently close to de-Sitter data develop into solutions of Einstein's equations \(\text{Ric}[g]=\Lambda g\) with positive cosmological constant \(\Lambda\), which are asymptotically simple in the past as well as in the future, whence null geodesically complete. Furthermore it is shown that hyperboloidal initial data (describing hypersurfaces which intersect future null infinity in a space-like two- sphere), which are sufficiently close to Minkowskian hyperboloidal data, develop into future asymptotically simple whence null geodesically future complete solutions of Einstein's equations \(\text{Ric}[g]=0\), for which future null infinity forms a regular cone with vertex \(i^+\) that represents future time-like infinity.