arXiv Machine Learning

Calibrating Generative Models to Feature Distributions with MMD Finetuning

arXiv:2606. 19496v1 Announce Type: new Abstract: Generative models can produce individually plausible samples while deviating substantially from a target set in the distribution of key features.

arXiv AI
Jun 10

MMD Guidance: Training-Free Distribution Adaptation for Diffusion Models via Maximum Mean Discrepancy Guidance

arXiv:2601. 08379v2 Announce Type: replace-cross Abstract: Pre-trained diffusion models have emerged as powerful generative priors for both unconditional and conditional sample generation, yet their outputs often deviate from the characteristics of user-specific target data.

By Matina Mahdizadeh Sani, Nima Jamali, Mohammad Jalali, Farzan Farnia
arXiv AI
Oct 1

Fenchel Tilting: Weighted Correction for Efficient Finetuning of Generative Models

Fenchel Tilt Flow Control (FTFC) is a new method for fine‑tuning pretrained generative models to arbitrary preference functions. It decouples utility optimization from model fitting by first learning reward and density‑ratio weights on pretrained samples, then freezing these weights to adjust a diffusion or flow model in a single importance‑weighted stage. The approach supports general f‑divergence penalties, achieves exact duality for concave utilities, and demonstrates up to 20× efficiency gains while outperforming baselines on image and molecule generation tasks.

By Maksim Bobrin, Maksim Zhdanov, Dmitry Dylov
arXiv Machine Learning
Oct 9

Ambient Discrete Diffusion: Using the Wrong Data at the Right Time for Data Efficient Learning

The paper introduces RefineMix, a framework for training discrete diffusion models when data is scarce, common in scientific settings. RefineMix strategically incorporates out‑of‑distribution data at specific diffusion times to enhance generalization without distorting the sampling distribution. Experiments across five domain‑shift scenarios show that RefineMix matches or surpasses in‑domain fine‑tuning, and in protein sequence generation it nearly doubles the proportion of novel, foldable, in‑family proteins produced from just 197 in‑domain examples.

By Julian Kleutgens, Mauricio Tec, Claudio Battiloro, Francesca Dominici, Giannis Daras
arXiv Machine Learning
Oct 28

Active Learning of Conditional Generative Models via the Transport Neural Tangent Kernel

The paper introduces the transport Neural Tangent Kernel (tNTK) to enable active learning for conditional generative models that produce distributional outputs. By decomposing the Wasserstein test risk into mean and shape components, the authors show that mean‑based active learning misses distributional shape, and propose tNTK as a tractable kernel that captures sensitivity of the predicted distribution to model parameters. Using tNTK as a Gaussian process covariance, they greedily select inputs that minimize posterior variance, and demonstrate that this distribution‑aware strategy outperforms mean‑based NTK baselines across several generative model types and datasets.

By Jayoung Ryu, Kyunghyun Cho, Romain Lopez
arXiv Machine Learning
Sep 29

Distribution-Conditioned Transport

The paper introduces Distribution‑Conditioned Transport (DCT), a framework that learns transport maps conditioned on embeddings of source and target distributions, allowing generalization to unseen distribution pairs. DCT supports semi‑supervised learning for distributional forecasting by leveraging distributions observed at only one condition. It is agnostic to the transport mechanism and is demonstrated on synthetic benchmarks and four biological applications, including batch effect transfer in single‑cell genomics and modeling T‑cell receptor sequence evolution.

By Nic Fishman, Gokul Gowri, Paolo L. B. Fischer, Marinka Zitnik, Omar Abudayyeh, Jonathan Gootenberg