The Hessian of tall-skinny networks is easy to invertThis package shows how to multiply the inverse of the Hessian of a deep network with a vector. If the Hessian-vector product is $H v$ for some fixed vector $v$ , we're interested in solving $H x = v$ for $x$ . Pearlmutter showed a clever way to compute the Hessian-vector-product for a deep net. By contrast, the paper and code in this repo shows how to compute the Hessian-inverse-product, the product of the inverse of the Hessian of a deep net with a vector. Solving this system naively requires a number of operations that scales cubically with the number of parameters in the deep net, which is impractical for most modern networks.