ON THE RELIABILITY OF INFLATION POTENTIAL RECONSTRUCTION - ART. NO. 043002

If primordial scalar and tensor perturbation spectra can be inferred f rom observations of the cosmic background radiation and large-scale st ructure, then one might hope to reconstruct a unique single-field infl aton potential capable of generating the observed spectra. In this pap er we examine conditions under which such a potential can be reliably reconstructed. For it to be possible at all, the spectra must be well fit by a Taylor series expansion. A complete reconstruction requires a statistically significant tensor mode to be measured in the microwave background. We find that the observational uncertainties dominate the theoretical error from use of the slow-roll approximation, and conclu de that the reconstruction procedure will never insidiously lead to an irrelevant potential.