Statistical Constraints on the Inflation Effective Potential from the   COBE DMR Results
  We explore constraints on various forms for the effective potential during inflation based upon a statistical comparison between inflation-generated fluctuations in the cosmic microwave background temperature and the COBE DMR results. Fits to the first year 53 A + B x 90 A + B cross correlation function using an effective potential of the form V(phi) = lambda*phi^x/x!, yield upper limits of x le 107 and x le 397 at the 1 sigma and 2 sigma confidence levels, while the same analysis produces a power law of index of n = 1.10 ^{+0.47}_{-0.64} which would imply an underestimate of x le 63 from the simple analytic relation between x and n . We also quantify new limits on the parameters for polynomial effective potentials. This work highlights the importance of a careful statistical treatment when seeking constraints on the inflation-generating effective potential. 
Hannu Kurki-Suonio and Grant J. Mathews