Thank you websterling for that heads-up!
...I wonder whether Planck 2015 will shed any light on the gravity wave/dust controversy?..
I wonder whether Planck 2015 will shed any light on the gravity wave/dust controversy?
My take-away:This came out yesterday, caveat lector. Roughly 270 authors are listed (216 plus something over 50).
A Joint Analysis of BICEP2/Keck Array and Planck Data
BICEP2/Keck, Planck Collaborations: P. A. R. Ade, N. Aghanim, Z. Ahmed, R. W. Aikin, K. D. Alexander, M. Arnaud, J. Aumont, C. Baccigalupi, A. J. Banday, D. Barkats, R. B. Barreiro, J. G. Bartlett, N. Bartolo, E. Battaner, K. Benabed, A. Benoit-Lévy, S. J. Benton, J.-P. Bernard, M. Bersanelli, P. Bielewicz, C. A. Bischoff, J. J. Bock, A. Bonaldi, L. Bonavera, J. R. Bond, J. Borrill, F. R. Bouchet, F. Boulanger, J. A. Brevik, M. Bucher, I. Buder, E. Bullock, C. Burigana, R. C. Butler, V. Buza, E. Calabrese, J.-F. Cardoso, A. Catalano, A. Challinor, R.-R. Chary, H. C. Chiang, P. R. Christensen, L. P. L. Colombo, C. Combet, J. Connors, F. Couchot, A. Coulais, B. P. Crill, A. Curto, F. Cuttaia, L. Danese, R. D. Davies, R. J. Davis, P. de Bernardis, A. de Rosa, G. de Zotti, J. Delabrouille, et al. (216 additional authors not shown)
(Submitted on 2 Feb 2015)
We report the results of a joint analysis of data from BICEP2/Keck Array and Planck. BICEP2 and Keck Array have observed the same approximately 400 deg2 patch of sky centered on RA 0h, Dec. −57.5deg. The combined maps reach a depth of 57 nK deg in Stokes Qand U in a band centered at 150 GHz. Planck has observed the full sky in polarization at seven frequencies from 30 to 353 GHz, but much less deeply in any given region (1.2 μK deg in Q and U at 143 GHz). We detect 150×353 cross-correlation in B-modes at high significance. We fit the single- and cross-frequency power spectra at frequencies above 150 GHz to a lensed-ΛCDM model that includes dust and a possible contribution from inflationary gravitational waves (as parameterized by the tensor-to-scalar ratio r). We probe various model variations and extensions, including adding a synchrotron component in combination with lower frequency data, and find that these make little difference to the r constraint. Finally we present an alternative analysis which is similar to a map-based cleaning of the dust contribution, and show that this gives similar constraints. The final result is expressed as a likelihood curve for r, and yields an upper limit r0.05<0.12 at 95% confidence. Marginalizing over dust and r, lensing B-modes are detected at 7.0σsignificance.
Comments: Provisionally accepted by PRL. Data and figures available for download at this http URL and this http URL
My comment: they got a lot of people on board.
The Planck site has a nice article about this-
Contrary to what others are reporting, their consensus is that it's mostly dust and microlensing, and that it sets an upper limit on the amount of gravitational waves from inflation- probably no more than about half the observed signal.
It does not, as has been claimed, mean that inflation, gravity waves from inflation, B-mode polarization of the CMB from gravity waves from inflation, or anything else is dead.
Résonaances has just posted his perspective-
That's a really terrible critique. Inflation makes more than just one prediction, and some of those predictions has been borne out by observation.Résonaances has a great Monty Python clip about the Taunting Frenchman! Thoughtful comment on the whole affair. The question that Paul Steinhardt raises (including at the Paris December 2014 Planck results conference) is not about inflation being dead, but that it is not science because it accommodates to any and all findings (BICEP or not BICEP, high r or low) with a cheerful cry of "I told you so!
Not dead in other words, just altogether too flexible.
It's certainly an impressive amount of work.. and so many papers. It'll take a while to read them all!
One particularly interesting result (and which was hinted at from the joint analysis paper), is that the [itex]m^2\phi^2[/itex] inflation model (the simplest, and the one which fit the previous BICEP data best!!!) is now disfavored at 3 sigma. But we shall have to wait for the full inflation paper to see what the Planck people have to say.
1. At the frequencies where the CMB is brightest, the small deviations in temperature are *much* brighter than the light from our own galaxy, except very close to the galactic center. Other galaxies further away are all much dimmer than the CMB at these frequencies.I just saw this Planck view of the milky way and wanted to ask, if all the galaxies in the U are radiating this much diffuse microwave energy, then how much might this total galaxy microwave output for the whole universe, along with the wide spread of red shifts, contribute to the amplitude of the cmbr measurements? My apologies If this is in the wrong place, I will gladly delete and start a new thread.