Recent Planck spacecraft observations of the Cosmic Microwave Background (CMB) – the fading glow of the Big Bang – have highlighted a discrepancy between cosmological results and predictions from other types of observations. The CMB is the oldest light in the Universe, and its study has allowed scientists to accurately measure cosmological parameters, such as the amount of matter in the Universe and its age. But an inconsistency arises when large-scale structures of the Universe, such as the distribution of galaxies, are observed.
By combining results from the Planck spacecraft and measurements of gravitational lensing, in order to deduce the mass of ghostly sub-atomic particles called neutrinos, observations of the Big Bang and the curvature of space-time have accurately measured the mass of these elementary particles for the first time.
Neutrinos interact very weakly with matter and so are extremely hard to study. They were originally thought to be massless but particle physics experiments have shown that neutrinos do indeed have mass and that there are several types, known as flavors by particle physicists. The sum of the masses of these different types has previously been suggested to lie above 0.06 eV (much less than a billionth of the mass of a proton).
In a recent paper, Richard Battye, from The University of Manchester School of Physics and Astronomy, and co-author Dr Adam Moss, from the University of Nottingham, have combined the data from Planck with gravitational lensing observations in which images of galaxies are warped by the curvature of space-time. The work used gravitational lensing data from the Canada-France-Hawaii Telescope Lensing Survey, the European Space Agency’s Planck spacecraft and the South Pole Telescope.
They conclude that the current discrepancies can be resolved if massive neutrinos are included in the standard cosmological model. They estimate that the sum of masses of neutrinos is 0.320 +/- 0.081 eV (assuming active neutrinos with three flavors).
Battye said, “We observe fewer galaxy clusters than we would expect from the Planck results and there is a weaker signal from gravitational lensing of galaxies than the CMB would suggest. A possible way of resolving this discrepancy is for neutrinos to have mass. The effect of these massive neutrinos would be to suppress the growth of dense structures that lead to the formation of clusters of galaxies.”
Moss concluded, “If this result is borne out by further analysis, it not only adds significantly to our understanding of the sub-atomic world studied by particle physicists, but it would also be an important extension to the standard model of cosmology which has been developed over the last decade.”
Preprint: Richard A. Battye, Adam Moss, 'Evidence for massive neutrinos from CMB and lensing observations', arXiv:1308.5870. Citation: Richard A. Battye and Adam Moss, 'Evidence for Massive Neutrinos from Cosmic Microwave Background and Lensing Observations', Phys. Rev. Lett. 112, 051303 6 February 2014, DOI: 10.1103/PhysRevLett.112.051303
- PHYSICAL SCIENCES
- EARTH SCIENCES
- LIFE SCIENCES
- SOCIAL SCIENCES
Subscribe to the newsletter
Stay in touch with the scientific world!
Know Science And Want To Write?
- Nobel Prize To Neutrino Oscillations
- Nobel Prize Validates Chinese Medicine? Nope.
- In Plain English: Why Neutrino Mass and Oscillation Won A Nobel Prize.
- Celiac Disease Diagnosis Gets Simplified
- Prenatal BPA Exposures (Don’t) Affect Birth Weight
- What Is Fat For?
- Machine learning vs NRA, a Grand Challenge
- "Very similar to the Laetrile story, which is the subject of the first chapter of Paul Offit's Do..."
- "Something to scream at:BREAKING NEWS: Boy, 10, suffering with jaw cancer who needs 'urgent surgery'..."
- "I remember Yoji Totsuka from Moriond Workshops, together with Koshiba. This was also a great loss..."
- "Thanks for writing. Happy to help. I could work 24/7 and not keep up with bad science and medicine..."
- "Thanks for this clarifying note for the non expert! As a physicist, I'm appalled by how my local..."
- Solid Reporting on the (Non) Risks of Roundup
- Calcium Heart Score May Predict Low Risk of Coronary Events
- Asthma Meds Safe for Babies, Despite Study Findings
- Effectiveness of Beta-blockers Questioned by New Study
- Defending Deserved Nobel Winners from Baseless Attacks
- Notable Progress Made on Male Birth Control Pill