Natural supergravity inflation

We show that a single uncharged chiral superfield, canonically coupled to N = 1 supergravity with vanishing superpotential, naturally drives inflation in the early universe for a class of simple Kähler potentials. Inflation occurs due to the one-loop generation of a Kähler anomaly proportional to R². The coefficient of this R² term is of the correct magnitude to describe all aspects of an inflationary cosmology, including sufficient amplitude perturbations and reheating. Higher order terms proportional to Rⁿ for n>=3 are naturally suppressed relative to the R² term and, hence, do not destabilize the theory.

Work supported in part by the Department of Energy under Contract No. DOE-AC02-76-ERO-3071.