Anninos, DionysiosNg, Gim SengStrominger, Andrew2013-08-062012Anninos, Dionysios, Gim Seng Ng, and Andrew E. Strominger. 2012. Future boundary conditions in de Sitter space. Journal of High Energy Physics 2012(2): 32.1029-8479http://nrs.harvard.edu/urn-3:HUL.InstRepos:10919791We consider asymptotically future de Sitter spacetimes endowed with an eternal observatory. In the conventional descriptions, the conformal metric at the future boundary \(I^+\) is deformed by the flux of gravitational radiation. We however impose an unconventional future “Dirichlet” boundary condition requiring that the conformal metric is flat everywhere except at the conformal point where the observatory arrives at \(I^+\). This boundary condition violates conventional causality, but we argue the causality violations cannot be detected by any experiment in the observatory. We show that the bulk-to-bulk two-point functions obeying this future boundary condition are not realizable as operator correlation functions in any normalizable de Sitter invariant vacuum, but they do agree with those obtained by double analytic continuation from anti-de Sitter space.en-USquantum physicsquantum field theorystring theoryelementary particlesclassical gravitationquantum gravitationrelativity theoryJournal Article2013-07-08Anninos, Dionysios, Ng, Gim Seng, Strominger, Andrew2013-08-0610.1007/JHEP02(2012)032