No-boundary measure and preference for large e-foldings in multi-field   inflation
  The no-boundary wave function of quantum gravity usually assigns only very small probability to long periods of inflation. This was a reason to doubt about the no-boundary wave function to explain the observational universe. We study the no-boundary proposal in the context of multi-field inflation to see whether the number of fields changes the situation. For a simple model, we find that indeed the no-boundary wave function can give higher probability for sufficient inflation, but the number of fields involved has to be very high. 
Dong-il Hwang, Soo A Kim, Bum-Hoon Lee, Hanno Sahlmann, Dong-han Yeom
gr-qc astro-ph.CO hep-th