Computational Physics Study Notes

Self-study course materials on topics at the intersection of physics, mathematics, and machine learning. Built for my own learning; shared in case others find them useful.

Carl Data Scientist Physics PhD github.com/carlm451

Projects
Live
Acoustics PINNs Helmholtz Equation

Physics-Informed Neural Network for 2D Acoustic Scattering

PINN solver for plane-wave scattering off a rigid cylinder, validated against the exact Bessel/Hankel series solution across wavenumbers ka = 0.5 to 2π. Includes Fourier feature ablation, BGT2 absorbing boundary conditions, and a multi-scatterer honeycomb extension. Interactive results dashboard with field comparisons, training diagnostics, and error analysis.

Results dashboard · 15-slide deck · 4 production ka values · March 2026
Statistical Mechanics Variational Inference Ising Model

VAN Sampling of 1D Ising Model in an External Field

Variational autoregressive network for sampling spin configurations of the 1D Ising model with an external magnetic field. Investigates the bias introduced by autoregressive factorization and compares VAN free energy estimates against exact transfer-matrix results.

Topological & Geometric Deep Learning
Live
Algebraic Topology Deep Learning Graph Theory

A Guided Introduction to Topological Deep Learning

Background for reading Hajij et al., "Topological Deep Learning: Going Beyond Graph Data." Builds from scratch: graphs → simplicial complexes → cell complexes → combinatorial complexes → higher-order message passing → Hodge theory → spectral methods. Includes worked examples, SVG diagrams, and connections to thermal physics throughout.

8 chapters · 3 parts · Worked matrix examples · February 2026
Live
Spectral Theory Graph Neural Networks Signal Processing

Discovering Graph Convolutions: From Circulant Matrices to the Graph Laplacian

How the DFT and graph convolutions emerge from the same idea — simultaneous diagonalization of a commuting algebra. Following Bamieh (2018): the DFT is discovered, not postulated. Then the same philosophy carries forward to graphs, the Laplacian, and GNNs. Includes interactive eigenvisual app and full worked examples.

7 chapters · 2 parts · Z₈ & 6-vertex running examples · March 2026
Variational Methods in Statistical Physics
Live
Statistical Mechanics Variational Inference

From Mean Field Theory to Variational Autoregressive Networks

Background for reading Wu, Wang & Zhang, "Solving Statistical Mechanics Using Variational Autoregressive Networks" (arXiv:1809.10606). Builds from the variational free energy principle through naïve mean field theory to the one-layer VAN architecture, with worked numerical examples, the bias question, and the REINFORCE training loop.

2 chapters · Worked examples · February 2026
Neural PDE Solvers
Neural Networks PDEs

Physics-Informed Neural Networks (PINNs)

Embedding PDE constraints into loss functions โ€” theory, training dynamics, failure modes, and when they actually work. See the Helmholtz PINN project for a worked example.

Planned
Live
Neural Operators Spectral Methods

Fourier Neural Operators for Parametric PDEs

Background for reading Li et al., "Fourier Neural Operator..." (arXiv:2010.08895). Sentence-by-sentence breakdown of operator learning, the neural operator architecture, and the Fourier-space parameterization, with concrete Darcy-flow examples and SVG diagrams throughout.

7 chapters · 4 parts · Darcy flow running example · March 2026
Deep Learning Functional Analysis

DeepONet & Neural Operator Theory

Universal approximation for operators, branch-trunk architectures, and the mathematical foundations connecting all neural PDE solvers.

Planned
Mathematical Foundations
Analysis Continuum Mechanics

PDEs for Machine Learning

The PDE theory neural solvers actually need: weak solutions, Sobolev spaces, variational formulations, and well-posedness.

Planned
Optimization Training Dynamics

Optimization for Deep Learning

SGD, Adam, Muon, loss landscapes, learning rate schedules, and why neural networks train at all.

Planned
Deep Learning Calculus

Autodiff & Backpropagation from Scratch

The chain rule, computational graphs, reverse-mode automatic differentiation, and building a minimal autograd engine in Python โ€” the calculus that makes deep learning work.

Planned
Computational Physics
Statistical Mechanics HPC

Molecular Dynamics Simulations

Force fields, integration schemes, thermostats, ensembles, and the bridge to machine-learned interatomic potentials.

Planned
Electrodynamics Simulation

Computational Electromagnetics

FDTD, method of moments, and how Maxwell's equations connect to the de Rham complex in topological deep learning.

Planned