How string theory can guide our search for dark energy, David Shlivko, GS (2265886)
Over the past century, astronomical observations have taught us that the observable universe—that is, the fabric of space itself—is expanding. For most of the universe's 14-billion-year history, this expansion has coincided with an expanding "Hubble horizon," which is a measure of how deep into space one can theoretically see. More recently, however, this Hubble horizon has been growing more slowly and appears to be approaching an asymptote, while the expansion of space itself is proceeding at an ever-increasing rate. It is possible that this strange behavior is caused by a physical substance permeating the universe—which we call dark energy—and physicists have been exploring possibilities for what this substance could be made of for decades. In this video, I explain how my research applies a conjecture from string theory to help narrow down the long list of these possibilities.