Theoretical Physics(DTP)
Physique théorique (DPT)

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Don N. PAGE
University of Alberta

Particle Production in a Tunneling Universe

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Rubakov and Vilenkin, and their collaborators, have debated whether there is catastrophic particle production in a tunneling universe. Here we examine the toy model in which one has a quantized scalar field evolving in a classical FRW spacetime which has is a real Lorentzian evolution followed by a real Euclidean evolution followed by a final real Lorentzian evolution (an L-E-L model). We find that if one chooses the vacuum state in the asymptotic past, then for modes with sufficiently large spatial momentum, the quantum state diverges within the Euclidean region. Therefore, the asymptotic past vacuum would not give a physical state in the asymptotic future in this L-E-L model.