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Constantinos Costis Daskalakis

12 accepted papers

2026

Learning Correlated Reward Models: Statistical Barriers and Opportunities

ICLR 2026poster

Random Utility Models (RUMs) are a classical framework for modeling user preferences and play a key role in reward modeling for Reinforcement Learning from Human Feedback (RLHF). However, a crucial shortcoming of many of these techniques is the Independence of Irrelevant Alternatives (IIA) assumptio…

Cited by 0SourcecodeScholar
2025

Ambient Diffusion Omni: Training Good Models with Bad Data

NeurIPS 2025spotlight

We show how to use low-quality, synthetic, and out-of-distribution images to improve the quality of a diffusion model. Typically, diffusion models are trained on curated datasets that emerge from highly filtered data pools from the Web and other sources. We show that there is immense value in the lo…

Cited by 0SourcecodeScholar
2025

Ambient Proteins - Training Diffusion Models on Noisy Structures

NeurIPS 2025spotlight

We present Ambient Protein Diffusion, a framework for training protein diffusion models that generates structures with unprecedented diversity and quality. State-of-the-art generative models are trained on computationally derived structures from AlphaFold2 (AF), as experimentally determined structur…

Cited by 0SourceScholar
2025

How Much is a Noisy Image Worth? Data Scaling Laws for Ambient Diffusion.

ICLR 2025poster

The quality of generative models depends on the quality of the data they are trained on. Creating large-scale, high-quality datasets is often expensive and sometimes impossible, e.g.~in certain scientific applications where there is no access to clean data due to physical or instrumentation constrai…

2025

Learning Gaussian DAG Models without Condition Number Bounds

ICML 2025poster

We study the problem of learning the topology of a directed Gaussian Graphical Model under the equal-variance assumption, where the graph has $n$ nodes and maximum in-degree $d$. Prior work has established that $O(d \log n)$ samples are sufficient for this task. However, an important factor that is…

Cited by 0SourcePDFScholar
2025

Learning High-dimensional Gaussians from Censored Data

AISTATS 2025poster

We provide efficient algorithms for the problem of distribution learning from high-dimensional Gaussian data where in each sample, some of the variable values are missing. We suppose that the variables are {\em missing not at random (MNAR)}. The missingness model, denoted by $\mathbb{S}(\mathbf{y})…

Cited by 0SourceScholar
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

Maximizing utility in multi-agent environments by anticipating the behavior of other learners

NeurIPS 2024poster

Learning algorithms are often used to make decisions in sequential decision-making environments. In multi-agent settings, the decisions of each agent can affect the utilities/losses of the other agents. Therefore, if an agent is good at anticipating the behavior of the other agents, in particular ho…

Cited by 5SourcePDFScholar
2024

On Tractable $\Phi$-Equilibria in Non-Concave Games

NeurIPS 2024poster

While Online Gradient Descent and other no-regret learning procedures are known to efficiently converge to a coarse correlated equilibrium in games where each agent's utility is concave in their own strategy, this is not the case when utilities are non-concave -- a common scenario in machine learnin…

Cited by 8SourcePDFScholar
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…

2021

Efficient Truncated Linear Regression with Unknown Noise Variance

NeurIPS 2021poster

Truncated linear regression is a classical challenge in Statistics, wherein a label, $y = w^T x + \varepsilon$, and its corresponding feature vector, $x \in \mathbb{R}^k$, are only observed if the label falls in some subset $S \subseteq \mathbb{R}$; otherwise the existence of the pair $(x, y)$ is hi…

2021

Near-Optimal No-Regret Learning in General Games

NeurIPS 2021oral

We show that Optimistic Hedge -- a common variant of multiplicative-weights-updates with recency bias -- attains ${\rm poly}(\log T)$ regret in multi-player general-sum games. In particular, when every player of the game uses Optimistic Hedge to iteratively update her action in response to the histo…

Cited by 130SourcePDFScholar