Polychronic Tunneling: New Tunneling Processes Experiencing Euclidean
  and Lorentzian Evolution Simultaneously
  We discuss new possible tunneling processes in the presence of gravity. We
formulate quantum tunneling using the Wheeler-deWitt canonical quantization and
the WKB approximation. The distinctive feature of our formulation is that it
accommodates the coexistence of Euclidean and Lorentzian evolution. It opens up
a new possibility of quantum tunneling; e.g. a bubble wall itself tunnels the
potential barrier pulling the field nearby, where the wall region experiences
the Euclidean evolution while the other regions experience the Lorentzian
evolution simultaneously. We execute numerical analysis and find that such a
process can have a much higher tunneling rate than that of the Coleman-De
Luccia bounce. We also find that the new tunneling processes exist even in the
decoupling regime of gravity and affect low energy phenomenology.
