The Signal and the Noise: Revolutionary New Cosmology at LIGO?

The discovery of gravitational waves promised to usher in a new age of empirical cosmology, with potentially significant implications for our theoretical understanding of the physical world.

Roger Penrose in a new paper is claiming that this promise has been delivered. At issue is “noise” in the signal of gravitational waves in the two LIGO detectors. The detectors are designed to detect a signal of gravitational waves distinct from background noise, but a group of researchers in Denmark have claimed that the noise in the data are correlated so suggesting, they assert, that the original gravitational wave detection was not of gravitational waves but rather correlated noise.

However, LIGO is sticking by its original claim.

Penrose asserts that the correlated noise is actually an astrophysical signal of gravitational origin

Such correlation would appear to imply that a significant component of this “noise” has actually a cosmological or astrophysical origin, rather than a local one. If such an external explanation can be provided, then this could resolve the dispute referred to at the beginning of this section

Penrose claims to provide just such an explanation, and that in terms of his Cyclic Conformal Cosmology which has the universe going through distinct aeons or cycles. According to Penrose it is a requirement of CCC that dark matter consists of very heavy particles called “erebons” whose decay is a gravitational process

It is indeed a reasonably robust implication of CCC that dark matter consists of particles— that I refer to as erebons (after the ancient Greek God of Darkness Erebos) that have a Planck mass, or thereabouts (~10-5 g), and a decay lifetime that could well be in excess of some 1010 years. Erebons are scalar particles (having zero spin), and interact only gravitationally (this much being a necessary feature of their key role in CCC as a kind of scalar conformal partner to gravitation)…

… Moreover, its decay would, correspondingly, take the form of, a total conversion into a highly oscillatory classical gravitational wave, travelling outwards from the erebon’s location, in an effectively classical impulsive spherical shell

Penrose argues that the frequency of gravitational waves arising from erebon decay are beyond the reach of the LIGO detectors, however they would be detectable as almost simultaneous effects of random character easily mischaracterised as noise.

Penrose argues that the correlated noise might well be detection of erebon decay.

For those of us of philosophical bent there is much of interest here. Conformal Cyclic Cosmology is related to Penrose’s idea’s regarding the very special character of the big bang singularity known as the Weyl Curvature Hypothesis, which is at variance with inflationary cosmology. It is also wrapped up with his ideas regarding quantum mechanics, which Penrose speaks of in the paper linked above, which are hardly mainstream.

I myself have long been fascinated by the Weyl Curvature Hypothesis, particularly its implications for our understanding of cosmological information. I’ve always found Penrose’s ideas regarding the physical world to be agreeable, even though most don’t and I’ve kind of been barracking for his views since high school.

Dark matter, inflation, quantum mechanics. That covers a lot of ground, and on each Penrose is a maverick offering a different conception of physics to that promoted by the wider community of physicists.

If Penrose is right we would have here some empirical evidence supporting his outlook on the physical world, which is pretty antiestablishment indeed potentially of revolutionary character.