Blog

Notes on whatever I am thinking about — usually numerical linear algebra, sometimes lattice field theory, sometimes a textbook I am working through.

Currently reading

Edit this list by hand as books come and go.

Modern Quantum Mechanics — Sakurai & Napolitano
Iterative Methods for Sparse Linear Systems — Saad

Convergence of a Krylov solver

A quick demonstration that executable code works on this site. The residual of a Krylov method typically falls geometrically until it stagnates.

Deflation and the low modes of the Dirac operator

The condition number of the Dirac operator D is governed by the ratio of its extreme eigenvalues, \kappa(D) = \lambda_{\max} / \lambda_{\min}. Because the smallest…