collaborators

5 papers

cs.LG2025

Differentially Private Bilevel Optimization: Efficient Algorithms with Near-Optimal Rates

Andrew Lowy, Daogao Liu

Bilevel optimization, in which one optimization problem is nested inside another, underlies many machine learning applications with a hierarchical structure -- such as meta-learnin…

cs.LG2025

Optimal Rates for Robust Stochastic Convex Optimization

Changyu Gao, Andrew Lowy, Xingyu Zhou +1

Machine learning algorithms in high-dimensional settings are highly susceptible to the influence of even a small fraction of structured outliers, making robust optimization techniq…

cs.LG2024

Private Federated Learning Without a Trusted Server: Optimal Algorithms for Convex Losses

Andrew Lowy, Meisam Razaviyayn

This paper studies federated learning (FL)--especially cross-silo FL--with data from people who do not trust the server or other silos. In this setting, each silo (e.g. hospital) h…

cs.LG2024

A Stochastic Optimization Framework for Private and Fair Learning From Decentralized Data

Devansh Gupta, A. S. Poornash, Andrew Lowy +1

Machine learning models are often trained on sensitive data (e.g., medical records and race/gender) that is distributed across different "silos" (e.g., hospitals). These federated…

cs.LG2024

Faster Algorithms for User-Level Private Stochastic Convex Optimization

Andrew Lowy, Daogao Liu, Hilal Asi

We study private stochastic convex optimization (SCO) under user-level differential privacy (DP) constraints. In this setting, there are users (e.g., cell phones), each possess…