activity
20202025
most citedPrivate Federated Learning Without a Trusted Server: Optimal Algorithms for Convex Losses

2 citations · 8 across the 12 of their papers we have counts for

collaborators

14 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.LG2024

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

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…

cs.LG2024

Private Heterogeneous Federated Learning Without a Trusted Server Revisited: Error-Optimal and Communication-Efficient Algorithms for Convex Losses

Changyu Gao, Andrew Lowy, Xingyu Zhou +1

We revisit the problem of federated learning (FL) with private data from people who do not trust the server or other silos/clients. In this context, every silo (e.g. hospital) has…

cs.LG2024

How to Make the Gradients Small Privately: Improved Rates for Differentially Private Non-Convex Optimization

Andrew Lowy, Jonathan Ullman, Stephen J. Wright

We provide a simple and flexible framework for designing differentially private algorithms to find approximate stationary points of non-convex loss functions. Our framework is base…

cs.LG2023

Optimal Differentially Private Model Training with Public Data

Andrew Lowy, Zeman Li, Tianjian Huang +1

Differential privacy (DP) ensures that training a machine learning model does not leak private data. In practice, we may have access to auxiliary public data that is free of privac…

cs.LG2022★ 1 cited

Stochastic Differentially Private and Fair Learning

Andrew Lowy, Devansh Gupta, Meisam Razaviyayn

Machine learning models are increasingly used in high-stakes decision-making systems. In such applications, a major concern is that these models sometimes discriminate against cert…

cs.LG2022★ 1 cited

Private Stochastic Optimization With Large Worst-Case Lipschitz Parameter

Andrew Lowy, Meisam Razaviyayn

We study differentially private (DP) stochastic optimization (SO) with loss functions whose worst-case Lipschitz parameter over all data may be extremely large or infinite. To date…

cs.LG2022

Private Non-Convex Federated Learning Without a Trusted Server

Andrew Lowy, Ali Ghafelebashi, Meisam Razaviyayn

We study federated learning (FL) -- especially cross-silo FL -- with non-convex loss functions and data from people who do not trust the server or other silos. In this setting, eac…

cs.LG2021★ 2 cited

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.LG2021★ 2 cited

A Stochastic Optimization Framework for Fair Risk Minimization

Andrew Lowy, Sina Baharlouei, Rakesh Pavan +2

Despite the success of large-scale empirical risk minimization (ERM) at achieving high accuracy across a variety of machine learning tasks, fair ERM is hindered by the incompatibil…

cs.LG2021★ 2 cited

Output Perturbation for Differentially Private Convex Optimization: Faster and More General

Andrew Lowy, Meisam Razaviyayn

Finding efficient, easily implementable differentially private (DP) algorithms that offer strong excess risk bounds is an important problem in modern machine learning. To date, mos…

math.OC2020

Efficient Search of First-Order Nash Equilibria in Nonconvex-Concave Smooth Min-Max Problems

Dmitrii M. Ostrovskii, Andrew Lowy, Meisam Razaviyayn

We propose an efficient algorithm for finding first-order Nash equilibria in min-max problems of the form , where the objective function is smoo…