213 citations · 1.1k across the 67 of their papers we have counts for
5 papers · 1 filter
On the convergence of local expansions of layer potentials
Charles L. Epstein, Leslie Greengard, Andreas Klöckner
In a recently developed quadrature method (quadrature by expansion or QBX), it was demonstrated that weakly singular or singular layer potentials can be evaluated rapidly and accur…
A fast semi-direct least squares algorithm for hierarchically block separable matrices
Kenneth L. Ho, Leslie Greengard
We present a fast algorithm for linear least squares problems governed by hierarchically block separable (HBS) matrices. Such matrices are generally dense but data-sparse and can d…
A fast, high-order solver for the Grad-Shafranov equation
Andras Pataki, Antoine J. Cerfon, Jeffrey P. Freidberg +2
We present a new fast solver to calculate fixed-boundary plasma equilibria in toroidally axisymmetric geometries. By combining conformal mapping with Fourier and integral equation…
Quadrature by Expansion: A New Method for the Evaluation of Layer Potentials
Andreas Klöckner, Alexander Barnett, Leslie Greengard +1
Integral equation methods for the solution of partial differential equations, when coupled with suitable fast algorithms, yield geometrically flexible, asymptotically optimal and w…
A consistency condition for the vector potential in multiply-connected domains
Charles L. Epstein, Zydrunas Gimbutas, Leslie Greengard +2
A classical problem in electromagnetics concerns the representation of the electric and magnetic fields in the low-frequency or static regime, where topology plays a fundamental ro…