Author Topic: Is BICEP2 wrong?  (Read 1710 times)

Is BICEP2 wrong?
« on: May 14, 2014, 11:27:24 AM »
There's a rumor that the team involved in the discovery of the primordial B-mode in the polarization of the Cosmic Microwave Background made a blunder:

To estimate polarized emission from the galactic dust, BICEP digitized an unpublished 353 GHz map shown by the Planck collaboration at a conference.  However, it seems they misinterpreted the Planck results: that map shows the polarization fraction for all foregrounds, not for the galactic dust only (see the "not CIB subtracted" caveat in the slide). Once you correct for that and rescale the Planck results appropriately, some experts claim that the polarized galactic dust emission can account for most of the BICEP signal. The rumor is that the BICEP team has now admitted to the mistake [Update: this last statement is disputed and outwardly denied].

Note that we should not conclude that there is no observable tensor modes in the CMB. Indeed, the tensor to scalar ratio of order 0.1 is probably consistent with the existing experimental data, and may be responsible for a part of the B-mode signal detected by BICEP. New data from Planck, POLARBEAR, ACTpole, and Keck Array should clarify the situation within a year from now.  However, at this point, there seems to be no statistically significant evidence for the primordial B-modes of inflationary origin in the CMB.

Is BICEP wrong?

Offline Solitary

Re: Is BICEP2 wrong?
« Reply #1 on: May 14, 2014, 12:29:50 PM »
I haven't got the slightest idea! All I know is my bicep signals are wrong in my left arm..   :confused: :wink2: Solitary
There is nothing more frightful than ignorance in action.

Offline stromboli

Re: Is BICEP2 wrong?
« Reply #2 on: May 14, 2014, 01:00:18 PM »
My understanding when it was published was that the conclusion, though not at that point reviewed by the Planck Institute- which I believe is still forthcoming- but that the results were pretty firm. we'll see.