Independent research · mathematics · machine learning

Logan Dixon Structure before scale.

I study structural questions in nonlinear systems and machine learning. Analytic arguments carry the general results; exact or certified computation enters where a finite witness or quantitative bound bears proof weight.

Research

Recent papers ask when local or finite structure determines global behavior: exactness for signed supports, injectivity mechanisms for ridge networks, and kernels of geometric representations.

Nonlinear optimization Analytic characterization · exact certificate for an explicit witness

Nonseparability characterizes SONC exactness for interior signed supports

Characterizes when an interior signed support is SONC-exact through nonseparability. The universal theorem is analytic; exact elimination, interval arithmetic, and certificate replay support the explicit three-negative witness and quantitative benchmark.

Neural networks Certified separation at the first open width

Averaged-Jacobian failure at the first open width of the Neural Jacobian Conjecture

Constructs an explicit sigmoid ridge network with an everywhere-positive Jacobian determinant and a segment-averaged Jacobian with negative determinant. The example separates pointwise positivity from the averaged-Jacobian mechanism at planar width four; the global behavior of its canonical witness is resolved in the follow-up below.

Neural networks Asymptotic polygon · winding multiplicity · validated open family

Asymptotic-polygon global inversion for planar saturating ridge networks and an injective neural-Jacobian separation witness

Develops a global inversion theorem for planar saturating ridge networks and resolves the certified separation witness as an injective global diffeomorphism onto an explicit nonconvex octagon. Exact and validated parameter certificates show that the mechanism persists on an explicit open neighborhood.

Algebra and geometry Exact identities · exhaustive finite checks · certified flip sequences

Ptolemy structure, sign rigidity, and pure-braid kernels in colored braid groupoid representations

Identifies the Ptolemy identity behind complex orthogonality, proves essential rigidity of the sign rule, and determines the rational kernel on the inner pure braid groups at n = 3 and n = 4 along certified Delaunay flip sequences.

AI systems and explanation

Interactive teaching tools and compact engineering studies make the same ideas inspectable at a different scale.

Interactive

AI Playgrounds

Twelve bilingual, single-file applets for search, logic, Bayesian reasoning, supervised and unsupervised learning, neural networks, vision, and reinforcement learning. Each runs in the browser without a build step.

Reinforcement learning

RLVR and GRPO studies

A CPU-scale reproduction of a qualitative DeepSeekMath ranking, paired with a compact operator zoo for comparing regularized policy-improvement updates under one notation and one training interface.

Engineering

Code portfolio

Projects across AI evaluation, retrieval, agents, machine learning, data systems, Rust protocols, infrastructure, and security. Each project states its implemented scope and includes tests or executable checks where appropriate.

About

I am an independent researcher and computer-science educator with a background spanning computer science, mathematics, physics, and secondary STEM education.

Research

I am interested in problems where a structural argument can replace brute force, or where computation can be made exact enough to carry a proof obligation. Current work crosses nonlinear optimization, neural networks, algebraic computation, and AI post-training.

Teaching

I teach computer science and AI. That work shapes the research presentation: definitions arrive before machinery, claims remain scoped to their evidence, and an implementation should reveal the idea rather than conceal it.

Contact

For research collaboration, technical review, or roles in mathematical AI, machine learning, and research engineering.