When computer scientists hang out at cocktail parties, they're apt to chat, among other things, about the single most important unsolved problem in computer science: the question, Does P = NP?

Early on in the study of quantum computers, computer scientists posed a question whose answer, they knew, would reveal something deep about the power of these futuristic machines. Twenty-five years ...

Raz, a professor at Princeton University and the Weizmann Institute of Science, and Tal, a postdoctoral fellow at Stanford University, define a specific kind of computational problem. They prove, with ...