The first “theory” of the dark cosmos was embodied in the Greek god of darkness, Erebus, one of the primordial deities born out of Chaos, the primeval void, foreshadowing the contemporary, emerging reality of the dark side of our universe. Enter Nobel-Prize Laurate, physicist Sir Roger Penrose, and his Erebon field theory, a novel explanation of dark matter that suggests that the Big Bang was not the origin of our universe. Despite ongoing searches, no signs of a dark matter particle have turned up.
Dark Photons –A Portal into the Dark Universe
Instead, physicists such as Penrose hope we will be able to find some dark force, a portal into the dark world. Such a “dark photon” would be dark matter’s equivalent of a photon, the way that dark matter particles interact with one another.
“Roger Penrose has always been willing — if not happy — to hold views that lie well outside of the scientific mainstream,” observes University of Chicago physicist and Senior Scientist and the Head of the Theoretical Astrophysics Group at the Fermi National Accelerator Laboratory, Dan Hooper, in an email to The Daily Galaxy. “He did this in the 19060s, Hooper wrote, “when he — correctly — argued that massive stars would ultimately become black holes. More recently, he has expressed skepticism about the conventional view that our very early universe went through an era of cosmic inflation, during which space expanded exponentially. Instead, he speculates that the Big Bang may not have been the beginning of our universe at all.”
“Dark photon searches are simultaneously straightforward and challenging, straightforward because the concept is general and simple enough that designing experimental searches is pretty easy, but challenging because we really have no clue where in the parameter space the dark photon could live,” says CERN Physicist James Beacham.
Conformal Cyclic Cosmology (CCC)
Penrose, reported Physics World, proposes a solution that points to the existence of an aeon before the Big Bang. Correlated noise in the two LIGO gravitational-wave detectors may provide evidence that the universe is governed by conformal cyclic cosmology (CCC) which assumes that the universe consists of a succession of eons, “the boundaries of infinity,” speculates Penrose of the University of Oxford. “The Big Bang was not the origin of our universe,” he observed.
The apparent noise is actually a real signal of gravitational waves generated by the decay of hypothetical dark-matter particles predicted by CCC — a competitor to the theory of inflation–from a previous eon that can be seen in the cosmic microwave background –electromagnetic radiation left over from an early stage of the universe in Big Bang cosmology.
Penose argues that a significant amount of this noise could be a signal of astrophysical or cosmological origin – and specifically CCC.
Physicists at the Niels Bohr Institute, writes Hamish Johnston, editor of physicsworld.com, pointed out that some of the noise in the two LIGO detectors appears to be correlated – with a delay that corresponds to the time it takes for a gravitational wave to travel the more than 3000 kilometers between the instruments.
First proposed over a decade ago by Penrose, CCC assumes that each aeon begins with a big bang and proceeds into an unending future in which the universe expands at an accelerating rate. As this expansion becomes infinitely large, Penrose argues that it can be transformed back into the next big bang.
Erebons –Planck-Mass Dark Matter Particles
Penrose, Johnston writes, says that a “reasonably robust implication of CCC” is that dark matter consists of particles called Erebons. As dark matter goes, Erebons are extremely heavy and have masses of about 10–5 g, and may have already been detected by accident –analogous to the first accidental detection of the cosmic microwave background. This is roughly the Planck mass and on a par with a grain of sand and about 22 orders of magnitude heavier than a proton.
When an Erebon decays, Penrose states, it deposits all its energy into a gravitational wave frequencies well above the detection capabilities of LIGO, and would be detected and recorded as near-instantaneous impulses that could be mistaken for noise rather than a signal from the birth of the cosmos.
Image credit: Dark Matter, Berkeley Lab