Rhys Grinter (@rhyswg.bsky.social)

Efficient high-resolution refinement in cryo-EM with stochastic gradient descent In the context of cryo-EM reconstruction, we provide a theoretical analysis showing that the condition number of the optimization problem is particularly large at high resolution, leading to slow convergence of gradient-based methods such as stochastic gradient descent. We then propose a method to overcome this issue by computing a preconditioner using Hutchinson's estimator, which results in improved convergence speed, as evidenced by numerical experiments. https://journals.iucr.org/paper?S205979832500511X