Cosmic Inflation in Question

Cosmic Inflation in Question

By Joshua Timmons, Biology, 2016

Revived after 34 years of collecting dust, the theory of cosmic inflation has been put on life support amid scrutiny by fellow scientists. Raphael Flauger, a theoretical physicist at NYU, has come forth arguing researchers underestimated the contribution of galactic dust to the polarization used as evidence of gravitational waves.

Visualized by CMB (Cosmic Microwave Background) maps, like the one below, researchers used the rotation of photons (B-mode polarization) as the basis for detection of cosmic inflation. This would agree with the concept that the universe “mushroomed” in its first moments of expansion, emitting ripples of gravitational waves.

The issue in the research stems from the paper’s authors putting the contribution of galactic dust at 3.5–5%, while Raphael Flauger, and other critics, put the actual number around 8–15%. Particles of dust are capable of absorbing and re-emitting light at frequencies close to the microwaves being detected by the BICEP telescopes. Although the difference in percentage can appear trivial, Flauger claims that 8–15% would be enough for the galactic dust to account for all of the polarization — meaning the total absence of detected gravitational waves.

This debate is not really a new one. When the paper first came out, there were discussions that the success of gravitational wave detection would depend up researchers ability to tease out the contribution of gravitational waves vs. confounding galactic dust.[1] James Bock, one of the lead researchers of the BICEP2 project, says the research is “certainly not being retracted.” Moving forward, the fate of cosmic inflation will rest in the hands of analyses aimed at determining how much galactic dust really lies above the South Pole BICEP telescopes.

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1 http://www.nature.com/news/milky-way-map-skirts-question-of-gravitational-waves-1.15181