The Primordial Inflation Explorer (PIXIE)

The Primordial Inflation Explorer (PIXIE) is an Explorer-class mission to characterize the signature of primordial inflation through its distinctive imprint on the cosmic microwave background.

An innovative optical design measures both linear polarization and the absolute intensity spectrum of the CMB and astrophysical foregrounds to background-limited sensitivity in 400 frequency channels spanning 2.5 decades in frequency from 30 GHz to 6 THz (1 cm to 50 micron wavelength). In addition to testing inflation by mapping the power spectrum of linear polarization, PIXIE will compare the CMB to a full-aperture blackbody calibrator to measure spectral distortions with sensitivity mu < 10^{-8} for the chemical potential and y < 2 x 10^{-9} for Compton distortions. Sensitivity at these levels opens a new window to the early universe, probing physical processes ranging from Big Bang cosmology to dark matter decay/annihilation to the nature of the first stars responsible for reionization.

I describe the PIXIE instrument and mission architecture needed for these new tests of the early universe.