Complexity Theory’s 50-Year Journey to the Limits of Knowledge
How hard is it to prove that problems are hard to solve? Meta-complexity theorists have been asking questions like this for decades. A string of recent results has started to deliver answers.
To Move Fast, Quantum Maze Solvers Must Forget the Past
Quantum algorithms can find their way out of mazes exponentially faster than classical ones, at the cost of forgetting the path they took. A new result suggests that the trade-off may be inevitable.
In Neural Networks, Unbreakable Locks Can Hide Invisible Doors
Cryptographers have shown how perfect security can undermine machine learning models.
The Computer Scientist Who Finds Life Lessons in Games
In Shang-Hua Teng’s work, theoretical and practical questions have long been intertwined. Now he’s turning his focus to the impractical.
Finally, a Fast Algorithm for Shortest Paths on Negative Graphs
Researchers can now find the shortest route through a network nearly as fast as theoretically possible, even when some steps can cancel out others.