Summary: | We present a new class of complex instantons in the context of ekpyrotic cosmological theories. These instantons, which satisfy the “no-boundary” boundary conditions, describe the emergence of a classical, contracting universe out of nothing. The ekpyrotic attractor is essential in guaranteeing an evolution towards a real, Lorentzian history of the universe. In the context of the no-boundary proposal, the relative probability for such ekpyrotic histories compared to inflationary ones is very high – in fact, assuming a bounce can be successfully incorporated, these new instantons currently describe the most likely origin of the universe.
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