Are you interested in the new Muon/Scion/Gluon method for training LLMs? To run Muon, you need to approximate the matrix sign (or polar factor) of the momentum matrix. We've developed an optimal method *The PolarExpress* just for this! If you're interested, climb aboard 1/x

How can classical numerical analysis help train deep nets faster? Climb aboard the Polar Express to find out... arxiv.org/abs/2505.16932 joint with @davpersson Robert M. Gower 🇺🇦 + Chris Musco