Field sparsening for the construction of the correlation functions in lattice QCD

Two field-sparsening methods, namely the sparse-grid method and random field selection method, are used in this paper for construction of 2-point 3-point correlation functions lattice QCD. We argue that, due to high among correlators at different points associated with source, current, sink locations, one can save a lot computational time by performing summation over subset sites. Furthermore, strategy, only needs store small fraction full quark propagators. It is found that number be reduced factor $\ensuremath{\sim}100$ point-source operator $\ensuremath{\sim}1000$ Gaussian-smeared operator, while uncertainties increase $\ensuremath{\sim}15%$. Therefore, modest cost resources, approach precision all-to-all using methods.