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Alex Dimakis

43 accepted papers

2026

GEPA: Reflective Prompt Evolution Can Outperform Reinforcement Learning

ICLR 2026oral

Large language models (LLMs) are increasingly adapted to downstream tasks via reinforcement learning (RL) methods like Group Relative Policy Optimization (GRPO), which often require thousands of rollouts to learn new tasks. We argue that the interpretable nature of language often provides a much ric…

Cited by 0SourcecodeScholar
2026

How to Train Your Advisor: Steering Black-Box LLMs with Advisor Models

ICML 2026poster

Frontier language models are deployed as black-box services, where model weights cannot be modified and customization is limited to prompting. We introduce Advisor Models, a method to train small open-weight models to generate dynamic, per-instance natural language advice that improves the capabilit…

Cited by 0SourceScholar
2026

OpenThoughts: Data Recipes for Reasoning Models

ICLR 2026oral

Reasoning models have made rapid progress on many benchmarks involving math, code, and science. Yet, there are still many open questions about the best train- ing recipes for reasoning since state-of-the-art models often rely on proprietary datasets with little to no public information available. To…

Cited by 0SourcecodeScholar
2026

Terminal-Bench: Benchmarking Agents on Hard, Realistic Tasks in Command Line Interfaces

ICLR 2026poster

AI agents may soon become capable of autonomously completing valuable, long-horizon tasks in diverse domains. Current benchmarks either do not measure real-world tasks, or are not sufficiently difficult to meaningfully measure frontier models. To this end, we present Terminal-Bench 1.5: a carefully…

Cited by 0SourcecodeScholar
2025

Ambient Diffusion Posterior Sampling: Solving Inverse Problems with Diffusion Models Trained on Corrupted Data

ICLR 2025poster

We provide a framework for solving inverse problems with diffusion models learned from linearly corrupted data. Firstly, we extend the Ambient Diffusion framework to enable training directly from measurements corrupted in the Fourier domain. Subsequently, we train diffusion models for MRI with acces…

2025

Geometric Median (GM) Matching for Robust k-Subset Selection from Noisy Data

ICML 2025poster

Data pruning -- the combinatorial task of selecting a small and representative subset from a large dataset, is crucial for mitigating the enormous computational costs associated with training data-hungry modern deep learning models at scale. Since large-scale data collections are invariably noisy, d…

Cited by 0SourcePDFScholar
2025

Infilling Score: A Pretraining Data Detection Algorithm for Large Language Models

ICLR 2025poster

In pretraining data detection, the goal is to detect whether a given sentence is in the dataset used for training a Large Language Model LLM). Recent methods (such as Min-K % and Min-K%++) reveal that most training corpora are likely contaminated with both sensitive content and evaluation benchmarks…

Cited by 0SourcePDFScholar
2025

Language models scale reliably with over-training and on downstream tasks

ICLR 2025poster

Scaling laws are useful guides for derisking expensive training runs, as they predict performance of large models using cheaper, small-scale experiments. However, there remain gaps between current scaling studies and how language models are ultimately trained and evaluated. For instance, scaling is…

2025

Large Language Models as Realistic Microservice Trace Generators

EMNLP 2025

Workload traces are essential to understand complex computer systems’ behavior and manage processing and memory resources. Since real-world traces are hard to obtain, synthetic trace generation is a promising alternative. This paper proposes a first-of-a-kind approach that relies on training a large

2025

Viewpoint Rosetta Stone: Unlocking Unpaired Ego-Exo Videos for View-invariant Representation Learning

CVPR 2025poster

Egocentric and exocentric perspectives of human action differ significantly, yet overcoming this extreme viewpoint gap is critical for applications in augmented reality and robotics. We propose ViewpointRosetta, an approach that unlocks large-scale unpaired ego and exo video data to learn clip-level…

Cited by 0SourcePDFScholar
2025

When Thinking Drifts: Evidential Grounding for Robust Video Reasoning

NeurIPS 2025poster

Video reasoning, the task of enabling machines to infer from dynamic visual content through multi-step logic, is crucial for advanced AI. While the Chain-of-Thought (CoT) mechanism has enhanced reasoning in text-based tasks, its application to video understanding remains underexplored. This paper pr…

Cited by 0SourceScholar
2024

4Diff: 3D-Aware Diffusion Model for Third-to-First Viewpoint Translation

ECCV 2024poster

"We present , a 3D-aware diffusion model addressing the exo-to-ego viewpoint translation task — generating first-person (egocentric) view images from the corresponding third-person (exocentric) images. Building on the diffusion model’s ability to generate photorealistic images, we propose a transfor…

2024

Consistent Diffusion Meets Tweedie: Training Exact Ambient Diffusion Models with Noisy Data

ICML 2024poster

Ambient diffusion is a recently proposed framework for training diffusion models using corrupted data. Both Ambient Diffusion and alternative SURE-based approaches for learning diffusion models from corrupted data resort to approximations which deteriorate performance. We present the first framework…

2024

DataComp-LM: In search of the next generation of training sets for language models

NeurIPS 2024poster

We introduce DataComp for Language Models, a testbed for controlled dataset experiments with the goal of improving language models. As part of DCLM, we provide a standardized corpus of 240T tokens extracted from Common Crawl, effective pretraining recipes based on the OpenLM framework, and a broad s…

Cited by 64SourcePDFScholar
2024

Put Myself in Your Shoes: Lifting the Egocentric Perspective from Exocentric Videos

ECCV 2024poster

"We investigate exocentric-to-egocentric cross-view translation, which aims to generate a first-person (egocentric) view of an actor based on a video recording that captures the actor from a third-person (exocentric) perspective. To this end, we propose a generative framework called Exo2Ego that dec…

Cited by 18SourcePDFScholar
2024

SVFT: Parameter-Efficient Fine-Tuning with Singular Vectors

NeurIPS 2024poster

Popular parameter-efficient fine-tuning (PEFT) methods, such as LoRA and its variants, freeze pre-trained model weights $\(\mathbf{W}\)$ and inject learnable matrices $\(\mathbf{\Delta W}\)$. These $\(\mathbf{\Delta W}\)$ matrices are structured for efficient parameterization, often using techniques…

2024

Warped Diffusion: Solving Video Inverse Problems with Image Diffusion Models

NeurIPS 2024poster

Using image models naively for solving inverse video problems often suffers from flickering, texture-sticking, and temporal inconsistency in generated videos. To tackle these problems, in this paper, we view frames as continuous functions in the 2D space, and videos as a sequence of continuous warpi…

2024

Which questions should I answer? Salience Prediction of Inquisitive Questions

EMNLP 2024main

Inquisitive questions — open-ended, curiosity-driven questions people ask as they read — are an integral part of discourse processing and comprehension. Recent work in NLP has taken advantage of question generation capabilities of LLMs to enhance a wide range of applications. But the space of inquis…

2023

Ambient Diffusion: Learning Clean Distributions from Corrupted Data

NeurIPS 2023poster

We present the first diffusion-based framework that can learn an unknown distribution using only highly-corrupted samples. This problem arises in scientific applications where access to uncorrupted samples is impossible or expensive to acquire. Another benefit of our approach is the ability to train…

2023

Consistent Diffusion Models: Mitigating Sampling Drift by Learning to be Consistent

NeurIPS 2023poster

Imperfect score-matching leads to a shift between the training and the sampling distribution of diffusion models. Due to the recursive nature of the generation process, errors in previous steps yield sampling iterates that drift away from the training distribution. However, the standard training obj…

2023

DataComp: In search of the next generation of multimodal datasets

NeurIPS 2023oral

Multimodal datasets are a critical component in recent breakthroughs such as CLIP, Stable Diffusion and GPT-4, yet their design does not receive the same research attention as model architectures or training algorithms. To address this shortcoming in the machine learning ecosystem, we introduce Data…

2023

HotProtein: A Novel Framework for Protein Thermostability Prediction and Editing

ICLR 2023poster

The molecular basis of protein thermal stability is only partially understood and has major significance for drug and vaccine discovery. The lack of datasets and standardized benchmarks considerably limits learning-based discovery methods. We present \texttt{HotProtein}, a large-scale protein datas…

2023

Restoration-Degradation Beyond Linear Diffusions: A Non-Asymptotic Analysis For DDIM-type Samplers

ICML 2023poster

We develop a framework for non-asymptotic analysis of deterministic samplers used for diffusion generative modeling. Several recent works have analyzed stochastic samplers using tools like Girsanov's theorem and a chain rule variant of the interpolation argument. Unfortunately, these techniques give…

Cited by 78SourcePDFScholar
2023

Solving Linear Inverse Problems Provably via Posterior Sampling with Latent Diffusion Models

NeurIPS 2023poster

We present the first framework to solve linear inverse problems leveraging pre-trained \textit{latent} diffusion models. Previously proposed algorithms (such as DPS and DDRM) only apply to \textit{pixel-space} diffusion models. We theoretically analyze our algorithm showing provable sample recover…

2022

Multitasking Models are Robust to Structural Failure: A Neural Model for Bilingual Cognitive Reserve

NeurIPS 2022accept

We find a surprising connection between multitask learning and robustness to neuron failures. Our experiments show that bilingual language models retain higher performance under various neuron perturbations, such as random deletions, magnitude pruning and weight noise. Our study is motivated by rese…

2022

Score-Guided Intermediate Level Optimization: Fast Langevin Mixing for Inverse Problems

ICML 2022spotlight

We prove fast mixing and characterize the stationary distribution of the Langevin Algorithm for inverting random weighted DNN generators. This result extends the work of Hand and Voroninski from efficient inversion to efficient posterior sampling. In practice, to allow for increased expressivity, we…

Cited by 26SourcePDFScholar
2022

Zonotope Domains for Lagrangian Neural Network Verification

NeurIPS 2022accept

Neural network verification aims to provide provable bounds for the output of a neural network for a given input range. Notable prior works in this domain have either generated bounds using abstract domains, which preserve some dependency between intermediate neurons in the network; or framed verifi…

2021

Fairness for Image Generation with Uncertain Sensitive Attributes

ICML 2021spotlight

This work tackles the issue of fairness in the context of generative procedures, such as image super-resolution, which entail different definitions from the standard classification setting. Moreover, while traditional group fairness definitions are typically defined with respect to specified protect…

2021

Instance-Optimal Compressed Sensing via Posterior Sampling

ICML 2021spotlight

We characterize the measurement complexity of compressed sensing of signals drawn from a known prior distribution, even when the support of the prior is the entire space (rather than, say, sparse vectors). We show for Gaussian measurements and \emph{any} prior distribution on the signal, that the po…

2021

Intermediate Layer Optimization for Inverse Problems using Deep Generative Models

ICML 2021spotlight

We propose Intermediate Layer Optimization (ILO), a novel optimization algorithm for solving inverse problems with deep generative models. Instead of optimizing only over the initial latent code, we progressively change the input layer obtaining successively more expressive generators. To explore th…

2021

Inverse Problems Leveraging Pre-trained Contrastive Representations

NeurIPS 2021poster

We study a new family of inverse problems for recovering representations of corrupted data. We assume access to a pre-trained representation learning network R(x) that operates on clean images, like CLIP. The problem is to recover the representation of an image R(x), if we are only given a corrupted…

2021

Robust Compressed Sensing MRI with Deep Generative Priors

NeurIPS 2021poster

The CSGM framework (Bora-Jalal-Price-Dimakis'17) has shown that deep generative priors can be powerful tools for solving inverse problems. However, to date this framework has been empirically successful only on certain datasets (for example, human faces and MNIST digits), and it is known to perform…

2020

Communication-Efficient Asynchronous Stochastic Frank-Wolfe over Nuclear-norm Balls

AISTATS 2020poster

Large-scale machine learning training suffers from two prior challenges, specifically for nuclear-norm constrained problems with distributed systems: the synchronization slowdown due to the straggling workers, and high communication costs. In this work, we propose an asynchronous Stochastic Frank Wo…

Cited by 7SourcePDFScholar
2019

Learning a Compressed Sensing Measurement Matrix via Gradient Unrolling

ICML 2019oral

Linear encoding of sparse vectors is widely popular, but is commonly data-independent – missing any possible extra (but a priori unknown) structure beyond sparsity. In this paper we present a new method to learn linear encoders that adapt to data, while still performing well with the widely used $\e…

2018

Gradient Coding from Cyclic MDS Codes and Expander Graphs

ICML 2018oral

Gradient coding is a technique for straggler mitigation in distributed learning. In this paper we design novel gradient codes using tools from classical coding theory, namely, cyclic MDS codes, which compare favourably with existing solutions, both in the applicable range of parameters and in the co…

Cited by 223SourcePDFScholar
2017

Contextual Bandits with Latent Confounders: An NMF Approach

AISTATS 2017poster

Motivated by online recommendation and advertising systems, we consider a causal model for stochastic contextual bandits with a latent low-dimensional confounder. In our model, there are $L$ observed contexts and $K$ arms of the bandit. The observed context influences the reward obtained through a l…

Cited by 55SourcePDFScholar
2017

Scalable Greedy Feature Selection via Weak Submodularity

AISTATS 2017poster

Greedy algorithms are widely used for problems in machine learning such as feature selection and set function optimization. Unfortunately, for large datasets, the running time of even greedy algorithms can be quite high. This is because for each greedy step we need to refit a model or calculate a…

Cited by 107SourcePDFScholar
2015

Stay on path: PCA along graph paths

ICML 2015poster

We introduce a variant of (sparse) PCA in which the set of feasible support sets is determined by a graph. In particular, we consider the following setting: given a directed acyclic graph G on p vertices corresponding to variables, the non-zero entries of the extracted principal component must coinc…

Cited by 8SourcePDFScholar