The effects of a fast-turning trajectory in multiple-field inflation
  The latest results from PLANCK impose strong constraints on features in the spectrum of the curvature perturbations from inflation. We analyse the possibility of particle production induced by sharp turns of the trajectory in field space in inflation models with multiple fields. Although the evolution of the background fields can be altered by particle production, we find rather modest changes in the power spectrum even for the most extreme case in which the entire kinetic energy of the scalar fields is converted into particles. 
Maciej Konieczka, Raquel H. Ribeiro, Krzysztof Turzynski
astro-ph.CO hep-th