Together with Tomo Takahashi and Richard Holman, Laura Mersini-Houghton published a series of papers in 2006 called “Avatars of the Landscape” making concrete, empirical predictions for the signatures of other universes on ours. Most importantly, this group demonstrated that the early entanglement of our universe with the rest of the "multiverse" added an independent source of variation to the strength of the Cosmic Microwave Background (CMB), a detailed fingerprint that allows astronomers to cast their gaze onto the first few moments of our universe’s existence. and to the distribution of matter around our universe, known as structure. In addition, the team calculated the strength of the entanglement and showed that its effect should be observable at large scales.
When they published their work, they didn’t dream that these predictions would be confirmed within their lifetimes. Amazingly, eight of the nine predictions were tested within a scant seven years, and all were in agreement with the data. Just last year, the Planck satellite data successfully tested seven of these predictions in one fell swoop.
The absence of Supersymmetry (SUSY) breaking at energies of about 1 trillion electron volts was confirmed by the Large Hadron Collider, in agreement with the ninth prediction. Only the Dark Flow prediction is still under debate, with two Planck team papers drawing conflicting conclusions. Taken together, these nine predictions represent a very stringent test of the theory, because all nine originate from a single theoretical framework. None of these predictions can be varied independently of the other eight in order to fit a particular set of data – the data must confirm them all, or the theory is ruled out.
Two previous measurements of the cosmic microwave background (COBE in 1992 and WMAP in 2007) have observed anomalies like those measured by Planck, but at a lower level of confidence. It may still turn out that the Planck anomalies are overestimated. If that turns out to be the case we will be back to square one. But if the anomalies are confirmed, and with it our first glimpse of the multiverse, astronomers will have achieved something remarkable. Not only will they have found evidence for other universes, they will also have found the first tests of string theory, whose description of the landscape important for cosmology. More broadly, the existence of multiple universes will demand to revisit and confront some of the most cherished notions about the cosmos and develop a new view of reality: do all universes live on the same underlying space-time fabric? Was there a notion of time before our Big Bang? Can we detect universes that are not entangled with ours? What determines the laws of nature? It will be an exciting time.
Via Dr. Stefan Gruenwald