[2511.01464] Split-Flows: Measure Transport and Information Loss Across Molecular Resolutions

Physics > Chemical Physics arXiv:2511.01464 (physics) [Submitted on 3 Nov 2025 (v1), last revised 26 Mar 2026 (this version, v2)] Title:Split-Flows: Measure Transport and Information Loss Across Molecular Resolutions Authors:Sander Hummerich, Tristan Bereau, Ullrich Köthe View a PDF of the paper titled Split-Flows: Measure Transport and Information Loss Across Molecular Resolutions, by Sander Hummerich and 2 other authors View PDF HTML (experimental) Abstract:By reducing resolution, coarse-grained models greatly accelerate molecular simulations, unlocking access to long-timescale phenomena, though at the expense of microscopic information. Recovering this fine-grained detail is essential for tasks that depend on atomistic accuracy, making backmapping a central challenge in molecular modeling. We introduce split-flows, a novel flow-based approach that reinterprets backmapping as a continuous-time measure transport across resolutions. Unlike existing generative strategies, split-flows establish a direct probabilistic link between resolutions, enabling expressive conditional sampling of atomistic structures and -- for the first time -- a tractable route to computing mapping entropies, an information-theoretic measure of the irreducible detail lost in coarse-graining. We demonstrate these capabilities on diverse molecular systems, including chignolin, a lipid bilayer, and alanine dipeptide, highlighting split-flows as a principled framework for accurate backmapping and systema...