We propose in this work a fast numerical algorithm for solving the equation of radiative transfer (ERT) in isotropic media. The algorithm has two steps. In the first step, we derive an integral equation for the angularly averaged ERT solution by taking advantage of the isotropy of the scattering kernel, and solve the integral equation with a fast multipole method (FMM). In the second step, we s...

Fast multipole methods (FMM) on distributed memory have traditionally used a bulk-synchronous model of communicating the local essential tree (LET) and overlapping it with computation of the local data. This could be perceived as an extreme case of data aggregation, where the whole LET is communicated at once. Charm++ allows a much finer control over the granularity of communication, and has a ...

An implementation of the fast multiple method (FMM) is performed for magnetic systems with long-ranged dipolar interactions. Expansion in spherical harmonics of the original FMM is replaced by expansion of polynomials in cartesian coordinates, which is considerably simpler. Under open boundary conditions, an expression for multipole moments of point dipoles in a cell is derived. These make the ...

The Fourier modal method (FMM) is based on Fourier expansions of the electromagnetic field and is inherently built for infinitely periodic structures. When the infinite periodicity assumption is not realistic, the finiteness of the structure has to be incorporated into the model. In this paper we discuss the recent extensions of the FMM for finite periodic structures and analyze their complexit...

In this paper we describe an efficient algorithm for computing the potentials of the form r−λ where λ ≥ 1. This treecode algorithm uses spherical harmonics to compute multipole coefficients that are used to evaluate these potentials. The key idea in this algorithm is the use of Gegenbauer polynomials to represent r−λ in a manner analogous to the use of Legendre polynomials for the expansion of ...

We present an adaptive fast multipole method for inverting the square root of the Laplacian in two dimensions. Solving this problem is the dominant computational cost in many applications arising in electrical engineering, geophysical fluid dynamics, and the study of thin films. It corresponds to the evaluation of the field induced by a planar distribution of charge or vorticity. Our algorithm ...

Fast-multipole and precorrected-FFT accelerated iterative methods have substantially improved the eeciency of Method-of-Moments (MOM) based 3-D electromagnetic analysis programs. In this paper we present a novel second-kind integral formulation and discretization approach for electrostatic analysis, as well as a projection technique for electroquasistatic analysis. We show that when these new a...

One way to implement a low-frequency or broadband fast multipole method is to use the spectral representation, or inhomogeneous plane-wave expansion, of the Green’s function. To significantly improve the error-controllability of the method, we propose a new interpolation and anterpolation scheme for the evanescent part. DOI: 10.2529/PIERS060907051636 The fast multipole method (FMM) can be used ...

Higher order panel methods are used to solve the Laplace equation in the presence of complex geometries. These methods are useful when globally accurate velocity or potential fields are desired as in the case of vortex based fluid flow solvers. This paper develops a fast multipole algorithm to compute velocity fields due to higher order, two-dimensional vortex panels. The technique is applied t...

A method is presented for the computation of Schwarz–Christoffel maps to polygons with tens of thousands of vertices. Previously published algorithms have CPU time estimates of the order O(N3) for the computation of a conformal map of a polygon with N vertices. This has been reduced to O(N logN) by the use of the fast multipole method and Davis’s method for solving the parameter problem. The me...