Using Quasi-random numbers to estimate the trace of an inverse matrix

The calculation of disconnected diagrams in lattice QCD is currently one of the main challenges of the field. The underlying calculation is the estimation of the trace of the inverse of a huge sparse matrix. I briefly review where disconnected quark diagrams occur in lattice QCD and some of the common algorithms used to calculate them. I discuss my attempts to develop algorithms based on quasi-random numbers and methods based on Hadamard matrices.