ECE 69500 - Fast Algorithms for Helmholtz and Laplace Integral Equations with Electromagnetic Applications
Course Details
Lecture Hours: 3 Credits: 3
Areas of Specialization:
- Fields and Optics
Normally Offered:
Each Fall
Campus/Online:
On-campus only
Requisites:
ECE 30411 and ECE 61800
Requisites by Topic:
Electromagnetics and numerical electromagnetics; familiarity with a computer programming or scripting language (eg, Python, MATLAB, Fortran, C++);
Catalog Description:
This course presents advanced integral equation formulations for electrostatics, magnetostatics, and full-wave electromagnetics, with emphasis on engineering modeling and large-scale computational analysis. The course begins with layer-potential representations and classical electromagnetic integral equations used in antenna, scattering, and interconnect problems, followed by discussion of discretization, singular-integral treatment, and numerical considerations arising in practical software implementations. The focus then shifts to iterative solvers and techniques for accelerating dense matrix-vector operations, including conjugate-gradient methods combined with fast Fourier transforms (CG-FFT), adaptive integral methods, and fast multipole methods. Both physics-based acceleration approaches using multipole and plane-wave expansions and algebraic techniques such as kernel-independent fast multipole methods are covered. Emphasis is placed on understanding algorithmic assumptions, accuracy-performance trade-offs, and applicability to realistic electromagnetic engineering problems.
Required Text(s):
None.
Recommended Text(s):
None.
Learning Outcomes
A student who successfully fulfills the course requirements will have demonstrated an ability to:
- Explain the role of single- and double-layer potentials in electrostatics and describe the associated jump relations and boundary operators used in boundary integral formulations.
- Formulate classical integral equation representations for electromagnetic boundary-value problems (e.g., EFIE, MFIE, CFIE), and articulate the assumptions and limitations underlying each formulation.
- Identify numerical challenges in integral equation discretizations, including singular and near-singular integrals, and explain standard strategies for self-term treatment, quadrature correction, and precorrected schemes.
- Recognize and interpret low-rank structure in integral equation matrices and explain how techniques such as SVD, matrix sketching, ACA, and related factorizations exploit this structure.
- Describe the fundamental principles of the Fast Multipole Method (FMM), including multipole and local expansions, translation operators, and hierarchical domain decomposition.
- Differentiate between classical, kernel-independent, and plane-wave FMM variants, and identify the regimes in which each approach is most effective.
- Explain how oscillatory kernels and high-frequency problems alter the structure of fast algorithms and motivate the use of rotations, directional methods, and plane-wave representations.
- Discuss the challenges posed by layered Green's functions, including Sommerfeld integrals, and explain how these challenges influence the design of fast solvers.
- Compare FMM-based acceleration techniques with FFT-based approaches, such as the precorrected-FFT and Adaptive Integral Method, and identify the trade-offs associated with each.
- Critically read and interpret research literature in integral equations and fast algorithms, identifying key assumptions, algorithmic choices, and sources of approximation or breakdown.
- Develop informed judgment about method selection, enabling students to assess which numerical techniques are appropriate for a given physical problem, kernel type, and geometric setting.
Lecture Outline:
| Unit Number | Topic |
|---|---|
| 1 | CEM Primer: Approximating functions on meshes, quadrature, and FEM I |
| 2 | CEM Primer: Approximating functions on meshes, quadrature, and FEM II |
| 3 | Electrostatics: Layer Potentials and Jump Relations I, II, III |
| 4 | Integral Equation Methods for Electromagnetics I, II, III |
| 5 | Code Development for Integral Equations I and II: Self-Term Treatment, Quadrature, and Precorrected Schemes |
| 6 | Matrix Compression Techniques: SVD, Matrix Sketches, ACA, and PMD |
| 7 | Kernel-Independent Fast Multipole Methods for Non-Oscillatory Kernels I, II |
| 8 | Single-Level Fast Multipole Method for the Laplace Equation in 2D |
| 9 | O(N log N) Fast Multipole Method for the Laplace Equation in 2D |
| 10 | O(N) Fast Multipole Method for the Laplace Equation in 3D I |
| 11 | O(N) Fast Multipole Method for the Laplace Equation in 3D II |
| 12 | Fast Multipole Method for the Helmholtz Equation in 3D; Fast Multipole Method for the Helmholtz Equation with Rotations in 3D |
| 13 | Plane-Wave Fast Multipole Algorithm: Plane-Wave Expansions and Diagonalization of Shift and Translation Operators |
| 14 | Interpolated Plane-Wave Fast Multipole Algorithm: Interpolation and Anterpolation |
| 15 | Fast Multipole Methods for Layered Green's Functions via Sommerfeld Integral Approximations |
| 16 | High-Frequency Kernel-Independent Fast Multipole Methods |
| 17 | Fast Fourier Transform Methods for Approximating Convolutions with Green's Functions |
| 18 | Adaptive Integral Method: Extending FFT-Based Methods to Irregular Source and Target Distributions |
| 19 | Advanced topics |
Assessment Method:
Homework, projects, class participation (4/2026)