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キーワード:
High Energy Physics - Theory, hep-th,Astrophysics, Cosmology and Extragalactic Astrophysics, astro-ph.CO,General Relativity and Quantum Cosmology, gr-qc
要旨:
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 incorporated, these new instantons currently describe the most
likely origin of the universe.
