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Raghu Meka

12 accepted papers

2023

On User-Level Private Convex Optimization

ICML 2023poster

We introduce a new mechanism for stochastic convex optimization (SCO) with user-level differential privacy guarantees. The convergence rates of this mechanism are similar to those in the prior work of Levy et al. 2021 and Narayanan et al. 2022, but with two important improvements. Our mechanism does…

Cited by 14SourcePDFScholar
2023

On the Benefits of Learning to Route in Mixture-of-Experts Models

EMNLP 2023long main

Mixture-of-Expert (MoE) Transformer models, such as the Switch Transformer, allow us to successfully scale up model sizes while keeping the amount of compute time fixed. Prior work has established the computational efficiency benefits of using these models. A core component of these models is a rout…

Cited by 0SourceScholar
2023

User-Level Differential Privacy With Few Examples Per User

NeurIPS 2023oral

Previous work on user-level differential privacy (DP) [Ghazi et al. NeurIPS 2021, Bun et al. STOC 2023] obtained generic algorithms that work for various learning tasks. However, their focus was on the *example-rich* regime, where the users have so many examples that each user could themselves solve…

Cited by 17SourcePDFScholar
2022

Hardness of Noise-Free Learning for Two-Hidden-Layer Neural Networks

NeurIPS 2022accept

We give superpolynomial statistical query (SQ) lower bounds for learning two-hidden-layer ReLU networks with respect to Gaussian inputs in the standard (noise-free) model. No general SQ lower bounds were known for learning ReLU networks of any depth in this setting: previous SQ lower bounds held onl…

Cited by 38SourcePDFScholar
2022

Lower Bounds on Randomly Preconditioned Lasso via Robust Sparse Designs

NeurIPS 2022accept

Sparse linear regression with ill-conditioned Gaussian random covariates is widely believed to exhibit a statistical/computational gap, but there is surprisingly little formal evidence for this belief. Recent work has shown that, for certain covariance matrices, the broad class of Preconditioned Las…

Cited by 5SourcePDFScholar
2022

Minimax Optimality (Probably) Doesn't Imply Distribution Learning for GANs

ICLR 2022poster

Arguably the most fundamental question in the theory of generative adversarial networks (GANs) is to understand when GANs can actually learn the underlying distribution. Theoretical and empirical evidence (see e.g. Arora-Risteski-Zhang '18) suggest local optimality of the empirical training objectiv…

Cited by 8SourcePDFScholar
2022

Sketching based Representations for Robust Image Classification with Provable Guarantees

NeurIPS 2022accept

How do we provably represent images succinctly so that their essential latent attributes are correctly captured by the representation to as high level of detail as possible? While today's deep networks (such as CNNs) produce image embeddings they do not have any provable properties and seem to work…

Cited by 1SourcePDFScholar
2020

Learning Some Popular Gaussian Graphical Models without Condition Number Bounds

NeurIPS 2020spotlight

Gaussian Graphical Models (GGMs) have wide-ranging applications in machine learning and the natural and social sciences. In most of the settings in which they are applied, the number of observed samples is much smaller than the dimension and they are assumed to be sparse. While there are a variety o…

Cited by 31SourcePDFScholar