There are a few points being raised lately on the first direct evidence on the universe inflation and the detection of gravitational waves:
1. The cosmic microwave polarization patterns referred to carry a lot of information. They do not solely refer to the gravitons (the gravitational waves - the ripples in space-time amalgam)
2. The indication to gravitons were carefully disentangled from many other irrelevant things.
3. Which could refer to objects - like dust or any thing of density that would simply cause the same (more or less) type of distortions in the cosmic microwave background that indicated the existence of gravitons.
4. For one thing, most importantly, no previous indication from a different method other than the polarization in cosmic microwave background has ever been made. An independent method is needed to confirm this uniquely new result against different set of results that would lead to same findings.
5. The detection was made 3 years ago, after which tedious calculations and investigations were made. Can such a polarization pattern be detected again? Why or why not?
6. We need to know how would, at least theoretically, the cosmic microwave polarization pattern purely (without the interference from any thing, like dust) look under the effect of gravitons? Can we do gravitons in a lab?
What methods should be followed to verify the findings of this discovery?
Well BICEP2 data are very dependant on isolating the tru CMB polarization (linked to cosmology from the early universe) from what are called the "forgrounds", anything that can polarized the CMB photons traversing matter that is much closer to us, even present in our own Galaxy: I mean local properties of dust. Forgrounds effects are expected to be intense than any signals from the cosmological polarization, so these foregrounds must be very well known so they can be subtracted from the global signal. Only the Planck HFI can do this. Planc's data on the foregrounds are progressively analyzed and these foregrounds will be very well known. In principle, Planck's foregrounds will be used to check BICEP2 data but also to chek its own data. BICEP2 is more sensitive on a vey portion of the Sky but Planck's data, less sensitive are coming from a huge fraction of the sky. Knowledge of the forgrounds will help to see if the B modes are indeed present. If not, well we need another more sensitive experiment, probably again an antarctica based one.
Such experiments, more sensitive than BICEP2 and more reliable if the forgrounds from Planck are known, should solve the problem of the detection of the B modes. These experiments are planned but we probably muts wait a few years before some results.
There are rumors that the Planck foreground calibration was not applied correctly and so the BiCEP2 results are in question. See http://resonaances.blogspot.com/2014/05/follow-up-on-bicep.html (and the links therein) for more.
"Now, serious flaws in the analysis have been revealed that transform the sure detection into no detection."
http://www.nature.com/news/big-bang-blunder-bursts-the-multiverse-bubble-1.15346
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