Illustrated portrait of Fred Xu

About Me

Fred Xu

Ph.D. student in Computer Science, University of California, Los Angeles

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I’m a Computer Science Ph.D. student at UCLA. I research probabilistic generative modeling (flow matching and diffusion), graph learning and uncertainty quantification, with applications to finance and science. My first- and co-first-author papers have appeared at NeurIPS, KDD and ACL, and I review for NeurIPS, ICML and ICLR.

Alongside the Ph.D. I’ve done industry research at Block, across two AI research internships, and at Hitachi and Amazon, applying this work to financial fraud detection, customer risk modeling, transaction foundation models and recommendation. Before graduate school I was a software engineer at NortonLifeLock, building security and privacy products.

Beyond the technical work, my interests run to AI and society, the philosophy of AI and continental philosophy, and on this site I write about those subjects, about literature, and about the papers behind my research.

Machine learning

Flow matching and diffusion modelsGraph learningUncertainty quantificationAnomaly and fraud detectionTime seriesScientific machine learning

Philosophy and society

AI and societyPhilosophy of AIContinental philosophy

Sep 2022 – present

Ph.D. in Computer Science

University of California, Los Angeles

Sep 2013 – Mar 2018

B.S. in Computer Science and Engineering, minor in Mathematics

University of California, Los Angeles

Jan – Sep 2026

AI Research Intern

Block, Inc. · Oakland, CA

  • Function-space flow matching. Proposed kernel Functional Flow Matching (kFFM), which replaces independent prior–data pairing with entropic optimal transport under a kernel-induced cost, with well-posedness and discretization-invariance guarantees; improved distributional matching over FFM, diffusion and OT baselines on time-series and PDE benchmarks. First-author paper at NeurIPS 2026.
  • Graph anomaly detection for fraud. Developed EB-GAD, a training-free, label-free anomaly detector that fits a graph prior by empirical Bayes and scores nodes by closed-form finite-horizon control energy; best or tied-best AUROC on 9 of 11 benchmarks, including four financial fraud networks of up to 3.7M nodes, with margins of up to 21.7 points. First-author paper at NeurIPS 2026.
  • Uncertainty quantification for GNNs. Proposed DSS-GNN, which expands node embeddings on graph-spectral and Wiener-chaos axes so a single representation supports calibrated prediction, out-of-distribution detection and distribution-shift robustness. First-author paper at NeurIPS 2026.
  • Graph generation. Co-developed FlowPhon, which generates dense graphs via flow matching on graphon operators; second-author paper under review.
  • Transaction foundation model. Built a GPT-style foundation model over customer transaction event sequences to model Cash App balance changes.

Aug 2025 – May 2026

STEM Specialist

Handshake AI, Inc. · Remote

  • LLM post-training data. Authored and solved advanced STEM problems and evaluated LLM-generated code to support alignment and improve the generation quality of LLM agents.

Jan – Sep 2025

AI Research Intern

Block, Inc. · Oakland, CA

  • Uncertainty estimation on graphs. Developed a graph neural network grounded in stochastic partial differential equations for uncertainty estimation on graph data. First-author paper at NeurIPS 2025.
  • Customer risk modeling. Implemented a probabilistic machine learning model with Monte Carlo simulation to estimate customer default risk and account lifetime value.
  • Time-series generation. Created a distributional diffusion model for time series built on path signatures.

Jun – Sep 2024

Research Scientist Intern

Hitachi America, Ltd. · Santa Clara, CA

  • Sensorless cargo monitoring. Engineered features and built regression and time-series models on global cargo-container temperature and humidity data to estimate shipment operational risk, improving on the baseline model by 30%.
  • Financial risk simulation. Ran Monte Carlo simulations over financial indicators and corporate portfolios, combined with time-series analysis, to estimate corporate financial risk under currency-rate and market shifts.

Jun – Sep 2022

Applied Scientist Intern

Amazon.com, Inc. · New York, NY

  • Audience embedding for recommendation. Implemented a deep-learning bipartite graph embedding model for audience representation in recommendation and user-group behavior prediction; proposed fuzzy-set embeddings to support logical queries, outperforming the baseline by at least 30%.

Jul 2018 – May 2021

Software Engineer

NortonLifeLock Inc. · Culver City, CA

  • Privacy Monitor (iOS). Developed the privacy monitor feature and client kit in Swift for the Norton Secure VPN iOS app, increasing customer interest in the privacy product by 45%.
  • Norton Secure VPN (Android). Maintained and extended the Android app (10M+ installs), shipping features including split tunneling and torrenting support.
  • Norton Security UWP. Developed, integrated and unit-tested core C#, Angular and C++/WinRT code for the Universal Windows Platform app; helped build the product threat model and implemented encryption, authentication and file-integrity mechanisms.
  • Secure file transfer and privacy MVPs. Built a cross-platform MVP (Android, iOS, PWA) for secure file transfer using TLS, RSA, AES-256 and SHA-256 with key management in Azure Key Vault, and a Chrome extension that opts users out of data-broker websites.
  1. NeurIPS 2026

    Improving Function Space Flow Matching with Kernel Optimal Transport

    Fred Xu, Thomas Markovich, Barbora Barancikova, Yizhou Sun

    arXiv

  2. NeurIPS 2026

  3. NeurIPS 2026

  4. KDD 2026

    FD-Bench: A Modular and Fair Benchmark for Data-driven Fluid Simulation

    Haixin Wang, Ruoyan Li, Fred Xu, Fang Sun, Kaiqiao Han, Zijie Huang, Ching Chang, Xiao Luo, Wei Wang, Yizhou Sun · Co-first author

    arXiv

  5. KDD 2026

    TIDAL: A Temporal Causal Diffusion Framework for Visualizing Knee Osteoarthritis Treatment Outcomes

    Second author

  6. ACL 2026

    Training Recipes for Agentic Reinforcement Learning in LLMs: A Survey

    Co-author

  7. NeurIPS 2025

  8. ACL 2024

    FUSE: Measure-Theoretic Compact Fuzzy Set Representation for Taxonomy Expansion

    Fred Xu, Song Jiang, Zijie Huang, Xiao Luo, Shichang Zhang, Adrian Chen, Yizhou Sun

    OpenReviewarXiv

  9. Manuscript

    Neural Hybrid Residual XRO Models for ENSO Forecasting

    First author

  10. Under review

    FlowPhon: Graph Generation via Flow Matching on Graphon Operators

    Second author

Jul – Aug 2023

Instructor, CS 97: Introduction to Data Science

UCLA Summer Institute

Taught advanced high-school students for college credit; rated 8.75 / 9 overall.

Teaching Assistant

UCLA Computer Science

CS 148 Introduction to Data Science, CS 247 Advanced Data Mining, CS 33 Computer Organization, CS M51A Logic Design of Digital Systems; average rating 8.4 / 9.

  • Reviewer for NeurIPS, ICML, ICLR, WWW and CIKM, and for PLOS journals
  • Talks on machine learning papers and tutorials at the UCLA Data Mining study group, student clubs and company knowledge-sharing meetings

Programming

Python, C++, SQL, Shell

ML & data

PyTorch, PyTorch Geometric, JAX, Hugging Face, scikit-learn, NumPy, pandas, Spark, AWS

LLMs

Fine-tuning and evaluation; OpenAI, Claude and Gemini APIs

Methods

Flow matching, diffusion models, uncertainty quantification, graph learning, time series, scientific ML

Languages

English, Chinese, German, Spanish