Susskind's Challenge to the Hartle-Hawking No-Boundary Proposal and Possible Resolutions

摘要

Given the observed cosmic acceleration, Leonard Susskind has presented thefollowing argument against the Hartle-Hawking no-boundary proposal for thequantum state of the universe: It should most likely lead to a nearly emptylarge de Sitter universe, rather than to early rapid inflation. Even if oneadds the condition of observers, they are most likely to form by quantumfluctuations in de Sitter and therefore not see the structure that we observe.Here I present my own amplified version of this argument and consider possibleresolutions, one of which seems to imply that inflation expands the universe tobe larger than 10^{10^{10^{122}}} Mpc.