AdS/CFT

Physicists are translating commonsense principles into strict mathematical constraints on how our universe must have behaved at the beginning of time.

For over two decades, physicists have pondered how the fabric of space-time may emerge from some kind of quantum entanglement. In Monika Schleier-Smith’s lab at Stanford University, the thought experiment is becoming real.

The five-decade-old paradox — long thought key to linking quantum theory with Einstein’s theory of gravity — is falling to a new generation of thinkers. Netta Engelhardt is leading the way.

In a landmark series of calculations, physicists have proved that black holes can shed information.

Einstein’s equations describe three canonical configurations of space-time. Now one of these three — important in the study of quantum gravity — has been shown to be inherently unstable.

A proposal for building wormhole-connected black holes offers a way to probe the paradoxes of quantum information.

Physicists have devised a holographic model of “de Sitter space,” the term for a universe like ours, that could give us new clues about the origin of space and time.

In the latest campaign to reconcile Einstein’s theory of gravity with quantum mechanics, many physicists are studying how a higher dimensional space that includes gravity arises like a hologram from a lower dimensional particle theory.

The theoretical physicist Joe Polchinski, who died February 2, left a tremendous professional and personal legacy, says a friend and collaborator.