How deep does the rabbit hole go? Deep enough, it turns out, to accommodate at least four movies, several videogames, a comic and countless pairs of sunglasses. In the 22 years since the “The Matrix” ...

We analyze two popular semidefinite programming relaxations for quadratically constrained quadratic programs with matrix variables. These relaxations are based on vector lifting and on matrix lifting; ...

This image released by Warner Bros. Pictures shows Keanu Reeves and Carrie-Anne Moss in a scene from "The Matrix Resurrections." (Warner Bros. Pictures via AP) ...