# Residues before the Cosmic microwave background event?

If the Cosmic microwave background happened when the universe was approximately 379,000 years old and it's still detectable today, is it probable/possible that other kinds of "radiation" from before that might be out there?

There should also exist primordial gravitational radiation. This gravitational radiation would be long wavelength gravitons (soft gravitons) that form another background. These would occur from the time quantum gravitation separated from gauge fields in a symmetry breaking in the first $10^{-40}$ to $10^{-35}$ seconds of the universe. Related to that is the production of gravitational radiation or gravitons in the inflationary period of the universe.
Can these be detected? At best maybe only indirectly. The BICEP2 team announced the detection of B-modes plasma in the CMB. Gravitational radiation with it polarization would induces the plasma of radiation dominated phase to emit radiation in certain polarization directions. This was announced in the spring of 2014. However, dust in the Milky Way galaxy can induce a similar polarization, and the certainty of detecting these early gravitational waves dropped from over $5$-$\sigma$ to $3$-$\sigma$.