Luca Ambrogioni

Assistant professor in AI at Radboud University’s Donders Institute and PI of the Generative Memory Lab, researching probabilistic machine learning, theoretical neuroscience, generative diffusion models, statistical physics, memory, and generalization.

Diffusion Models Generate Images Through Critical Instability Windows

Luca Ambrogioni argues that trained diffusion models generate images through brief instability windows rather than uniform step-by-step denoising. In a Microsoft Research generative modeling seminar, he links score dynamics, conditional entropy and statistical-physics phase transitions to show how low-frequency spatial modes soften at critical times, allowing noise to organize into coherent structure. Experiments on patch models, Fashion-MNIST and ImageNet models are presented as evidence that these critical windows govern both pattern formation and the timing of effective guidance.

Microsoft ResearchMay 26, 202617 min read