COBE differential microwave radiometer constraints on an inflation model with nonminimal scalar field

We derive the power spectra of the scalar- and tenser-type structures gener ated in a chaotic-type inflation model based on nonminimally coupled scalar field with a self-interaction. By comparing contributions of both structur es to the anisotropy of the cosmic microwave background radiation with the four-year COBE differential microwave radiometer data on quadrupole anisotr opy we derive constraints on the ratio of self-coupling and nonminimal coup ling constants, and the expansion rate in the inflation era. The requiremen t for a successful amount of inflation further constrains the relative amou nt of a tenser-type contribution.