Well, it’s official that this afternoon’s announcement of a “major discovery” is going to be from the BICEP team, and it specifically concerns the BICEP2 CMB telescope experiment. I’ve just got back to Sussex (after a weekend in Cardiff) and will be following the events in among other things I have to do before going off to give a lecture at 5pm GMT.
The schedule of events is as follows: there will be a special webcast presenting the first results from the BICEP2 CMB telescope. The webcast will begin with a presentation for scientists 10:45-11:30 EDT, followed by a news conference 12:00-1:00 EDT.
You can join the webcast from the link at http://www.cfa.harvard.edu/news/news_conferences.html
Papers and data products will be available at 10:45 EDT from http://bicepkeck.org/
EDT is four hours behind Greenwich Mean Time so the webcast will begin at 14:45 GMT, i.e. in about half an hour.
In the mean time, for those of you wondering what these BICEPS are all about, here is a useful graphic in which a Harvard astrophysicist demonstrates the possibilities:
14:36 The press conference server has gone down. There’s no truth in the rumour that ex-members of the Clover collaboration have sabotaged it.
14:42 There’s a grave danger that this press conference will run into tea time.
14:45 The BICEP2 papers are now live at http://bicepkeck.org/
14:48 Straight to the headline: R=0.2 (+0.07, -0.05) with R=0 rejected at about 7 sigma, if you like things stated in such terms…
14:53 Here’s the crucial graph. Results a bit higher than the expected signal at l in range 200-300?
15:06 The news avalanche has started, e.g. here at the BBC, but there is some concern about the shape of the spectrum.
15:10 I’m not getting anything from the press conference, so may have missed important details. It seems to me though that there’s a significant possibility of some of the polarization signal in E and B not being cosmological. This is a very interesting result, but I’d prefer to reserve judgement until it is confirmed by other experiments.
15:35 Despite the press hype there’s still some scepticism among cosmologists arising from the strange-looking shape of the spectrum. I’m not convinced myself. Anyway, I have to sign off now in order to prepare a lecture..
16:20 Back-of-the-envelope time: if the result is correct then the inflationary energy scale is about 2×1016 GeV. That’s just two orders of magnitude below the Planck scale…
18:19 Returned from my 5pm Theoretical Physics lecture. Couldn’t resist spending 30 minutes talking about BICEP2, though I did tell them it’s not in the examination.
18:25 Main points of controversy:
- there seems to be evidence of leakage of temperature into polarization (lines in Fig. 5);
- there’s an excess in the B-B spectrum at l~250 shown above;
- there’s an excess at low l in the E-E spectrum
- there’s a deficit at low l in the cross-correlation with Keck
There may be a connection between 1. and 2.-4. If 2.-4 are real then they may be evidence of something interesting that requires more than a straightforward modification of inflation (such as might include just a running of the spectral index).
18:35 Other controversy: why has this result been announced before the paper has been published or even peer-reviewed?