Strong Dynamics and Natural Inflation

We continue our investigation of the 4d effective field theory for closed string axions in Type II compactifications with D-branes. The inclusion of St"uckelberg couplings for the axions requires the presence of chiral fermions at D-brane intersections, whose interactions at strong non-Abelian gauge coupling induce mass terms for the axions and scalar chiral condensate excitations, dubbed infladrons. The set-up allows for a realization of natural-like inflation with a closed string axion as inflaton and a flattened scalar potential due to the back-reaction of the more massive infladrons. We further point out that this large field inflationary model is not compromised by axionic wormhole corrections.