AI research engineer

Julian Chan

I build LLM agents and train models for physical simulation.

PhD researcher in astrophysics and machine learning at the University of Surrey.

Julian Chan

Selected work

Budgeted Search for AI4Science

A study of how an LLM uses task descriptions and validation feedback to choose neural-operator fine-tuning settings. I compared search methods under matched budgets and built the accompanying package for recording and replaying runs.

Accepted to the NeurIPS 2026 AI4Science Workshop. Equal contribution with Javier Mora Jimenez.

Research Brief Agent

I built a FastAPI agent that searches arXiv and a Qdrant paper index, reads sources and writes cited briefs. It checks citations, limits tool calls and records traces in Langfuse. Offline scenario tests run in CI.

Differentiable ML with Tesseract

I trained a PyTorch turbulence closure through a JAX spectral solver. In-process training reduced 500-step rollout vorticity MSE by 71.7% versus the solver alone across 32 test trajectories. A separate demonstration passes gradients through two served Tesseract components.

Solver adjoints and JAX/PyTorch PINNs for Burgers viscosity estimation.

Neural ODE surrogates

I trained parameter-conditioned neural ODEs on N-body simulations of black hole binaries and tested them on held-out trajectories and an unseen higher-resolution case. Their predictions feed a semi-analytical model of binary merger times.

First-author paper published in Monthly Notices of the Royal Astronomical Society, 2026.

About

My research models black hole binary evolution with machine learning. I also develop GPU simulation software and differentiable JAX/PyTorch pipelines.

I hold an MSc in Computer Science from Swansea University and an MSci in Physics from the University of Birmingham.

Scientific ML CV
ML & evaluation
Python, PyTorch, JAX, LLM agents, model evaluation
Services & tooling
FastAPI, Qdrant, Langfuse, Docker, GitHub Actions
Scientific computing
Differentiable simulation, inverse problems, CuPy, SLURM / HPC

Contact

julianchan8897@gmail.com