Chaotic inflation, radiative corrections and precision cosmology

Abstract

We employ chaotic (phi(2) and phi(4)) inflation to illustrate the important role radiative corrections can play during the inflationary phase. Yukawa interactions of phi, in particular, lead to corrections of the form -k phi(4) ln(phi/mu), where K > 0 and mu is a renormalization scale. For instance, phi(4) chaotic inflation with radiative corrections looks compatible with the most recent WMAP (5 year) analysis, in sharp contrast to the tree level case. We obtain the 95% confidence limits 2.4 x 10(-14) less than or similar to k less than or similar to 5.7 x 10(-14), 0.931 less than or similar to n(s) less than or similar to 0.958 and 0.038 less than or similar to r less than or similar to 0.205, where n(s) and r respectively denote the scalar spectral index and scalar to tensor ratio. The limits for phi(2) inflation are k less than or similar to 7.7 x 10(-15), 0.929 less than or similar to n(s) less than or similar to 0.966 and 0.023 less than or similar to r less than or similar to 0.135. The next round of precision experiments should provide a more stringent test of realistic chaotic phi(2) and phi(4) inflation.