Speaker
Stefan Güttel
(The University of Manchester)
Description
Randomized sketching is a promising tool to reduce the number of inner products computed in Krylov methods for solving large systems of linear equations $Ax = b$, or more generally, when approximating the action of a matrix function on a vector, $f(A)b$. For the case of linear systems, it has recently been observed that one can often get away with completely inner product-free Krylov-based preconditioners when a stabilizing outer iteration (like FGMRES) is used. In this talk we discuss whether similar (almost) inner product-free methods can be devised for the $f(A)b$ problem.
Author
Stefan Güttel
(The University of Manchester)