Gravitational waves according to Planck

Gravitational waves according to Planck

Scientists of the Planck collaboration, and in particular the Trieste team, have conducted a series of in-depth checks on the discovery recently publicized by the Antarctic Observatory, which announced last spring that it had detected some direct effects of gravitational waves on cosmic microwave background radiation, a potentially groundbreaking discovery in the field of cosmology. Analysis of the Planck satellite data demonstrates that the effect of contaminating sources, such as gases from our galaxy, cannot be ruled out.

No one has ever directly observed , phenomena predicted by Einstein's theory of General Relativity, and such a discovery would have for the study of the Universe. Last March, however, the team behind the BICEP2 project made a ground-breaking announcement: the Antarctic observatory had detected a signal referable to gravitational waves. The study claimed to have excluded possible contaminants (other sources that could have generated the same signal) and that the observation was therefore to be considered genuine. But not everyone agreed and many scientists expressed doubts. To test the observation, the team in charge of analysing the Planck satellite data (in which the International School for Advanced Studies SISSA of Trieste, INAF-Astronomical Observatory of Trieste and the University of Trieste participate at one of the two Data Processing Centres) carried out a series of checks in the same portion of sky observed by BICEP, both at the same and at a higher frequency ranges.

The study, now available in the archives (and due for publication in Astronomy & Astrophysics on Monday), in part damps down enthusiasm. "Unfortunately, according to our analysis, the effect of contaminants and in particular of gases present in our Galaxy cannot be ruled out", explains Carlo Baccigalupi, SISSA cosmologist and one of the authors of the study.

The strength of Planck – which provides a coarser-grained picture of the sky compared to BICEP2 – is that it observes the Universe at a very wide range of frequencies (nine bands from 30 to 857 GHz, as against the single frequency of 150 GHz used by BICEP2). And it is precisely this "multiple" image which enabled the Planck scientists to establish that the effect of a contaminant may indeed be at work.

The news is not all bad, however, and could instead prove "fruitful": "we have started a collaboration with BICEP2. We are directly comparing their data with the Planck data, in the same frequency, 150 GHz, and trying to exploit the image of the contaminants we reach with Planck at other frequencies", continues Baccigalupi. "This way, we hope to be able to give a definitive answer. In fact, we might find that it was indeed a contamination, but, given that we're optimists, we might even be able to exclude it with confidence. This way, Planck could give a crucial contribution to the discovery of evidence of gravitational waves from the Big Bang in cosmic background radiation. Such a discovery would open a completely new window onto unknown scenarios in the study of the primordial Universe and very-high-energy physics".

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Journal information: Astronomy & Astrophysics

Provided by International School of Advanced Studies (SISSA)
Citation: Gravitational waves according to Planck (2014, September 22) retrieved 17 July 2019 from
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Sep 23, 2014
I remember catching so much s--t for posting that they found nothing. How could they if the big bang didn't happen and the universe is expanding where magnetic feilds are growing, and deflating where they are shrinking?



Sep 23, 2014
They dont want to say unequivocally that the BICEP2 conclusions are flawed. In the meanwhile it's fairly convincing that the BICEP2 results were likely false. I read the original paper and highlighted invalid assumptions and false conclusions. I'm annoyed because a search for 'Gravity waves detected' makes it seem to the less informed that a detection has been verified. Fraud, misrepresentation, dirty lying bastards just wanted grant money. Should be unlawful and the BICEP2 team members should be hung, drawn and quartered.

Breathe, take meds, chill. It's only the reputation of scientific integrity involved. Who cares.

I should care less?

Sep 23, 2014
I remember catching so much s--t for posting that they found nothing.

Because you, like everyone else who said that, couldn't come up with any good argument as to why it was wrong. It was a lucky guess, it had nothing to do with actually discussing problems.

Sep 23, 2014
They will never detect "gravity waves" 'cos gravity does not exist, it was "invented" not discovered. There is no evidence whatsoever for the existence of gravity which does not equally apply to expansion theory. On the other hand, expansion theory is directly attributable to observed expansion of photons over time (redshift). In other words, redshift is not caused by the expansion of the universe a' la Hubble, but by decay over time of all matter, including photons.

Sep 23, 2014
t had nothing to do with actually discussing problems.
- brainless imp

Go follow previous discussions you fool. BICEP2 researchers were clearly full of shit by publication without any review. A disgusting abuse of scientific publication.

They are frauds. Nothing less. Long slow torture for the egotistical scum. No less.

Sep 23, 2014
As I suggested at the time .. Pons and Fleischmann would be dumbfounded as for the double standards. ( yes, turning in his grave).

Absolutely disgusting abuse of process. The BICEP2 researchers are money and fame hungry evil scumbags.

Outrageous. They should die slowly and be made an example of, publicly.

Sep 23, 2014
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