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Christopher De Sa

41 accepted papers

2025

Compute-Optimal LLMs Provably Generalize Better with Scale

ICLR 2025poster

Why do larger language models generalize better? To explore this question, we develop generalization bounds on the pretraining objective of large language models (LLMs) in the compute-optimal regime, as described by the Chinchilla scaling laws. We introduce a novel, fully empirical Freedman-type mar…

Cited by 0SourcePDFScholar
2025

Machine Unlearning Doesn't Do What You Think: Lessons for Generative AI Policy and Research

NeurIPS 2025oral

"Machine unlearning" is a popular proposed solution for mitigating the existence of content in an AI model that is problematic for legal or moral reasons, including privacy, copyright, safety, and more. For example, unlearning is often invoked as a solution for removing the effects of specific infor…

Cited by 0SourceScholar
2025

Zeroth-Order Fine-Tuning of LLMs with Transferable Static Sparsity

ICLR 2025poster

Zeroth-order optimization (ZO) is a memory-efficient strategy for fine-tuning Large Language Models using only forward passes. However, applying ZO fine-tuning in memory-constrained settings such as mobile phones and laptops remains challenging since these settings often involve weight quantization,…

Cited by 0SourcePDFScholar
2024

Arbitrariness and Social Prediction: The Confounding Role of Variance in Fair Classification

AAAI 2024technical

Variance in predictions across different trained models is a significant, under-explored source of error in fair binary classification. In practice, the variance on some data examples is so large that decisions can be effectively arbitrary. To investigate this problem, we take an experimental approa…

2024

Diffusion Models With Learned Adaptive Noise

NeurIPS 2024spotlight

Diffusion models have gained traction as powerful algorithms for synthesizing high-quality images. Central to these algorithms is the diffusion process, a set of equations which maps data to noise in a way that can significantly affect performance. In this paper, we explore whether the diffusion p…

2024

QTIP: Quantization with Trellises and Incoherence Processing

NeurIPS 2024spotlight

Post-training quantization (PTQ) reduces the memory footprint of LLMs by quantizing weights to low-precision datatypes. Since LLM inference is usually memory-bound, PTQ methods can improve inference throughput. Recent state-of-the-art PTQ approaches use vector quantization (VQ) to quantize multiple…

2024

QuIP$\#$: Even Better LLM Quantization with Hadamard Incoherence and Lattice Codebooks

ICML 2024poster

Post-training quantization (PTQ) reduces the memory footprint of LLMs by quantizing their weights to low-precision. In this work, we introduce QuIP#, a weight-only PTQ method that achieves state-of-the-art results in extreme compression regimes ($\le$ 4 bits per weight) using three novel techniques.…

2024

Searching for Efficient Linear Layers over a Continuous Space of Structured Matrices

NeurIPS 2024poster

Dense linear layers are the dominant computational bottleneck in large neural networks, presenting a critical need for more efficient alternatives. Previous efforts to develop alternatives have focused on a small number of hand-crafted structured matrices, and have neglected to investigate whether t…

2024

Shadow Cones: A Generalized Framework for Partial Order Embeddings

ICLR 2024poster

Hyperbolic space has proven to be well-suited for capturing hierarchical relations in data, such as trees and directed acyclic graphs. Prior work introduced the concept of entailment cones, which uses partial orders defined by nested cones in the Poincar\'e ball to model hierarchies. Here, we introd…

2023

CocktailSGD: Fine-tuning Foundation Models over 500Mbps Networks

ICML 2023poster

Distributed training of foundation models, especially large language models (LLMs), is communication-intensive and so has heavily relied on centralized data centers with fast interconnects. Can we train on slow networks and unlock the potential of decentralized infrastructure for foundation models?…

Cited by 49SourcePDFScholar
2023

Coordinating Distributed Example Orders for Provably Accelerated Training

NeurIPS 2023poster

Recent research on online Gradient Balancing (GraB) has revealed that there exist permutation-based example orderings for SGD that are guaranteed to outperform random reshuffling (RR). Whereas RR arbitrarily permutes training examples, GraB leverages stale gradients from prior epochs to order exampl…

2023

InfoDiffusion: Representation Learning Using Information Maximizing Diffusion Models

ICML 2023poster

While diffusion models excel at generating high-quality samples, their latent variables typically lack semantic meaning and are not suitable for representation learning. Here, we propose InfoDiffusion, an algorithm that augments diffusion models with low-dimensional latent variables that capture hig…

Cited by 41SourcePDFScholar
2023

Maximizing Communication Efficiency for Large-scale Training via 0/1 Adam

ICLR 2023poster

1-bit gradient compression and local steps are two representative techniques that enable drastic communication reduction in distributed SGD. Their benefits, however, remain an open question on Adam-based large model pre-training (e.g. BERT and GPT). In this paper, we demonstrate the non-linearity in…

2023

QuIP: 2-Bit Quantization of Large Language Models With Guarantees

NeurIPS 2023spotlight

This work studies post-training parameter quantization in large language models (LLMs). We introduce quantization with incoherence processing (QuIP), a new method based on the insight that quantization benefits from incoherent weight and Hessian matrices, i.e., from the weights being even in magnitu…

2023

Riemannian Residual Neural Networks

NeurIPS 2023poster

Recent methods in geometric deep learning have introduced various neural networks to operate over data that lie on Riemannian manifolds. Such networks are often necessary to learn well over graphs with a hierarchical structure or to learn over manifold-valued data encountered in the natural sciences…

Cited by 16SourcePDFScholar
2023

STEP: Learning N:M Structured Sparsity Masks from Scratch with Precondition

ICML 2023poster

Recent innovations on hardware (e.g. Nvidia A100) have motivated learning N:M structured sparsity masks from scratch for fast model inference. However, state-of-the-art learning recipes in this regime (e.g. SR-STE) are proposed for non-adaptive optimizers like momentum SGD, while incurring non-trivi…

Cited by 15SourcePDFScholar
2023

TART: A plug-and-play Transformer module for task-agnostic reasoning

NeurIPS 2023poster

Large language models (LLMs) exhibit in-context learning abilities which enable the same model to perform several tasks without any task-specific training. In contrast, traditional adaptation approaches, such as fine-tuning, modify the underlying models for each specific task. In-context learning, h…

2022

A General Analysis of Example-Selection for Stochastic Gradient Descent

ICLR 2022spotlight

Training example order in SGD has long been known to affect convergence rate. Recent results show that accelerated rates are possible in a variety of cases for permutation-based sample orders, in which each example from the training set is used once before any example is reused. In this paper, we de…

2022

From Gradient Flow on Population Loss to Learning with Stochastic Gradient Descent

NeurIPS 2022accept

Stochastic Gradient Descent (SGD) has been the method of choice for learning large-scale non-convex models. While a general analysis of when SGD works has been elusive, there has been a lot of recent progress in understanding the convergence of Gradient Flow (GF) on the population loss, partly due…

Cited by 10SourcePDFScholar
2022

GraB: Finding Provably Better Data Permutations than Random Reshuffling

NeurIPS 2022accept

Random reshuffling, which randomly permutes the dataset each epoch, is widely adopted in model training because it yields faster convergence than with-replacement sampling. Recent studies indicate greedily chosen data orderings can further speed up convergence empirically, at the cost of using more…

2022

How Low Can We Go: Trading Memory for Error in Low-Precision Training

ICLR 2022poster

Low-precision arithmetic trains deep learning models using less energy, less memory and less time. However, we pay a price for the savings: lower precision may yield larger round-off error and hence larger prediction error. As applications proliferate, users must choose which precision to use to tra…

2022

Low-Precision Stochastic Gradient Langevin Dynamics

ICML 2022spotlight

While low-precision optimization has been widely used to accelerate deep learning, low-precision sampling remains largely unexplored. As a consequence, sampling is simply infeasible in many large-scale scenarios, despite providing remarkable benefits to generalization and uncertainty estimation for…

2022

Model Preserving Compression for Neural Networks

NeurIPS 2022accept

After training complex deep learning models, a common task is to compress the model to reduce compute and storage demands. When compressing, it is desirable to preserve the original model's per-example decisions (e.g., to go beyond top-1 accuracy or preserve robustness), maintain the network's struc…

2022

Understanding Hyperdimensional Computing for Parallel Single-Pass Learning

NeurIPS 2022accept

Hyperdimensional computing (HDC) is an emerging learning paradigm that computes with high dimensional binary vectors. There is an active line of research on HDC in the community of emerging hardware because of its energy efficiency and ultra-low latency---but HDC suffers from low model accuracy, wit…

2021

Equivariant Manifold Flows

NeurIPS 2021poster

Tractably modelling distributions over manifolds has long been an important goal in the natural sciences. Recent work has focused on developing general machine learning models to learn such distributions. However, for many applications these distributions must respect manifold symmetries—a trait whi…

2021

Hyperparameter Optimization Is Deceiving Us, and How to Stop It

NeurIPS 2021poster

Recent empirical work shows that inconsistent results based on choice of hyperparameter optimization (HPO) configuration are a widespread problem in ML research. When comparing two algorithms J and K searching one subspace can yield the conclusion that J outperforms K, whereas searching another can…

2021

Low-Precision Reinforcement Learning: Running Soft Actor-Critic in Half Precision

ICML 2021spotlight

Low-precision training has become a popular approach to reduce compute requirements, memory footprint, and energy consumption in supervised learning. In contrast, this promising approach has not yet enjoyed similarly widespread adoption within the reinforcement learning (RL) community, partly becaus…

Cited by 30SourcePDFScholar
2021

Meta-Learning Divergences for Variational Inference

AISTATS 2021poster

Variational inference (VI) plays an essential role in approximate Bayesian inference due to its computational efficiency and broad applicability. Crucial to the performance of VI is the selection of the associated divergence measure, as VI approximates the intractable distribution by minimizing this…

Cited by 7SourcePDFScholar
2021

Variance Reduced Training with Stratified Sampling for Forecasting Models

ICML 2021spotlight

In large-scale time series forecasting, one often encounters the situation where the temporal patterns of time series, while drifting over time, differ from one another in the same dataset. In this paper, we provably show under such heterogeneity, training a forecasting model with commonly used stoc…

Cited by 24SourcePDFScholar
2020

AMAGOLD: Amortized Metropolis Adjustment for Efficient Stochastic Gradient MCMC

AISTATS 2020poster

Stochastic gradient Hamiltonian Monte Carlo (SGHMC) is an efficient method for sampling from continuous distributions. It is a faster alternative to HMC: instead of using the whole dataset at each iteration, SGHMC uses only a subsample. This improves performance, but introduces bias that can cause S…

2020

Differentiating through the Fréchet Mean

ICML 2020poster

Recent advances in deep representation learning on Riemannian manifolds extend classical deep learning operations to better capture the geometry of the manifold. One possible extension is the Fr{é}chet mean, the generalization of the Euclidean mean; however, it has been difficult to apply because it…

2019

Building Efficient Deep Neural Networks With Unitary Group Convolutions

CVPR 2019poster

We propose unitary group convolutions (UGConvs), a building block for CNNs which compose a group convolution with unitary transforms in feature space to learn a richer set of representations than group convolution alone. UGConvs generalize two disparate ideas in CNN architecture, channel shuffling (…

Cited by 34PDFScholar
2015

Global Convergence of Stochastic Gradient Descent for Some Non-convex Matrix Problems

ICML 2015poster

Stochastic gradient descent (SGD) on a low-rank factorization is commonly employed to speed up matrix problems including matrix completion, subspace tracking, and SDP relaxation. In this paper, we exhibit a step size scheme for SGD on a low-rank least-squares problem, and we prove that, under broad…

Cited by 206SourcePDFScholar