arXiv Machine Learning

Beyond Random Couplings: Contrastive Noise Alignment in Generative Flows

The paper introduces Contrastive Noise Alignment (CNA), a training-time method for generative flow models that dynamically aligns Gaussian noise with data samples using a cross-modal InfoNCE objective. By modeling noise as an interacting particle system and regularizing with angular entropy and radial norm penalties, CNA reduces arbitrary data-noise couplings and flow curvature. Empirical results show that CNA improves generation quality, lowering FID by over 50% for few-step pixel-space generation compared to standard rectified flow and outperforming optimal transport baselines by at least 24%.

arXiv AI
Oct 2

Manifold-Constrained Initial Noise Optimization for Efficient Generative Model Alignment

The paper introduces ZeNOVA, a gradient‑free method for aligning initial noise in generative models. It uses annealed soft‑value guidance, manifold‑constrained hyperspherical Langevin dynamics, and Metropolis‑Hastings jumps to address instability in black‑box reward settings. Experiments on image and video models show ZeNOVA outperforms existing zeroth‑order baselines by more stably optimizing noise toward higher rewards.

By Jinho Chang, Jong Chul Ye
arXiv AI
Oct 15

Posterior Flow Matching

arXiv:2610.13994v1 Announce Type: cross Abstract: Flow matching learns how to transport noise toward data, but its mean prediction does not directly report the endpoint uncertainty remaining at an in...

By Chenrui Ma, Xi Xiao, Lin Zhao, Xinru Jiang, Tianyang Wang, Yanning Shen, Ferdinando Fioretto
arXiv Computer Vision
Sep 18

Training Flow Matching: The Role of Weighting and Parameterization

The paper investigates training objectives for denoising-based generative models, focusing on loss weighting and output parameterization such as noise-, clean image-, and velocity-based formulations. It conducts a systematic numerical study across synthetic datasets with controlled geometry and real image data, evaluating denoising accuracy via PSNR and generative quality via FID. The goal is to disentangle how training choices interact with data manifold dimensionality, model architecture, and dataset size, offering practical design insights rather than proposing a new method.

By Anne Gagneux, S\'egol\`ene Martin, R\'emi Gribonval, Mathurin Massias
arXiv Machine Learning
Oct 12

Disentangling Total-Variance and Signal-to-Noise-Ratio Improves Diffusion Models

The paper introduces a total‑variance/signal‑to‑noise‑ratio (TV/SNR) framework that allows independent control of TV and SNR in diffusion models. By replacing exponentially exploding TV schedules with constant TV while keeping the SNR schedule, the authors achieve consistent improvements in generation efficiency. The approach generalizes the SNR schedule from optimal transport flow matching and works across various reverse diffusion solvers, reducing the search space to two interpretable parameters for robust sampling in scientific applications such as molecular structure generation.

By Khaled Kahouli, Winfried Ripken, Stefan Gugler, Oliver T. Unke, Klaus-Robert M\"{u}ller, Shinichi Nakajima