Galaxy-Size Gravitational-Wave Detector Hints at Exotic Physics

For those who want a bit more details in a fairly accessible format there was a recent and IMHO interesting talk[1] at Perimeter Institute about these results from one of the founders of NANOGrav.

The NANOGrav collaboration behind these results was using the Arecibo telescope as one of their primary data sources. Due to the extremely low frequencies involved, they relied on data over many years to reduce noise. Here's what they said before it fell apart[2]:

Many of these pulsars can be timed only with Arecibo thanks to its incredible sensitivity. NANOGrav’s most recent analyses show that a detection of gravitational waves is likely imminent. Any gap longer than several months in our 16 years of data will impede our ability to characterize the low-frequency gravitational-wave universe and carry out the associated multi-messenger science. It will also likely add systematics to our datasets that will make them more difficult to model. If Arecibo wasn’t repaired, its loss would be a disaster for both US gravitational-wave and radio astronomy.

They made a follow-up statement after the loss[3], so it's not a fatal blow but definitely a tough loss:

While our future sensitivity to gravitational waves will decrease without Arecibo, legacy Arecibo observations will anchor combined future datasets which will be integral to opening this new window on the universe at low frequency gravitational waves and to gleaning insights into how galaxies form and evolve.

[1]: http://pirsa.org/20100068

[2]: http://nanograv.org/announcement,/press/2020/08/19/Arecibo.h...

[3]: http://nanograv.org/announcement,/press/2020/12/02/Arecibo.h...

Although the article reads as sensational, it is actually based on three recently accepted papers in Physical Review Letters. It also gives some insight into several research groups wanting to claim being the first having seen evidence for new physics, be it from sparse observational data.

Fascinating, particularly the analysis of pulsar signals for meta-phenomena.

I bet gravitational waves aren’t the only thing we’ll learn to detect from pulsars.

I just think that if there were a wave detector the size of a galaxy I'd have probably seen it by now, right?