Aligned natural inflation: Monodromies of two axions

Natural (axionic) inflation[1] can accommodate sizeable primordial tensor modes but suffers from the necessity of trans-Planckian variations of the inflaton field. This problem can be solved via the mechanism of aligned axions[2], where the aligned axion spirals down in the potential of other axions. We elaborate on the mechanism in view of the recently reported observations of the BICEP2 collaboration[3]. (C) 2014 The Authors. Published by Elsevier B.V.