Dynamic Conditional Optimal Transport through Simulation-Free Flows (2404.04240v2)
Abstract: We study the geometry of conditional optimal transport (COT) and prove a dynamical formulation which generalizes the Benamou-Brenier Theorem. Equipped with these tools, we propose a simulation-free flow-based method for conditional generative modeling. Our method couples an arbitrary source distribution to a specified target distribution through a triangular COT plan, and a conditional generative model is obtained by approximating the geodesic path of measures induced by this COT plan. Our theory and methods are applicable in infinite-dimensional settings, making them well suited for a wide class of Bayesian inverse problems. Empirically, we demonstrate that our method is competitive on several challenging conditional generation tasks, including an infinite-dimensional inverse problem.
- Building normalizing flows with stochastic interpolants. arXiv preprint arXiv:2209.15571, 2022.
- Stochastic interpolants: A unifying framework for flows and diffusions. arXiv preprint arXiv:2303.08797, 2023a.
- Stochastic interpolants with data-dependent couplings. arXiv preprint arXiv:2310.03725, 2023b.
- Gradient flows: in metric spaces and in the space of probability measures. Springer Science & Business Media, 2005.
- A user’s guide to optimal transport. Modelling and Optimisation of Flows on Networks: Cetraro, Italy 2009, Editors: Benedetto Piccoli, Michel Rascle, pages 1–155, 2013.
- Brandon Amos et al. Tutorial on amortized optimization. Foundations and Trends in Machine Learning, 16(5):592–732, 2023.
- Conditional score-based diffusion models for Bayesian inference in infinite dimensions. Advances in Neural Information Processing Systems, 36, 2024.
- Conditional sampling with monotone GANs: from generative models to likelihood-free inference. arXiv preprint arXiv:2006.06755, 2020.
- Understanding the training of infinitely deep and wide ResNets with conditional optimal transport. arXiv preprint arXiv:2403.12887, 2024.
- A computational fluid mechanics solution to the Monge-Kantorovich mass transfer problem. Numerische Mathematik, 84(3):375–393, 2000.
- MCMC methods for diffusion bridges. Stochastics and Dynamics, 8(03):319–350, 2008.
- Hybrid Monte Carlo on Hilbert spaces. Stochastic Processes and their Applications, 121(10):2201–2230, 2011.
- Vladimir Igorevich Bogachev and Maria Aparecida Soares Ruas. Measure Theory, volume 2. Springer, 2007.
- Supervised training of conditional monge maps. Advances in Neural Information Processing Systems, 35:6859–6872, 2022a.
- Proximal optimal transport modeling of population dynamics. In International Conference on Artificial Intelligence and Statistics, pages 6511–6528. PMLR, 2022b.
- Vector quantile regression: An optimal transport approach. The Annals of Statistics, 44(3):1165 – 1192, 2016. doi: 10.1214/15-AOS1401. URL https://doi.org/10.1214/15-AOS1401.
- Conditional Wasserstein distances with applications in Bayesian OT flow matching. arXiv preprint arXiv:2403.18705, 2024.
- Riemannian flow matching on general geometries. arXiv preprint arXiv:2302.03660, 2023.
- Stargan v2: Diverse image synthesis for multiple domains. In Proceedings of the IEEE/CVF Conference on Computer Vision and Pattern Recognition, pages 8188–8197, 2020.
- MCMC methods for functions: Modifying old algorithms to make them faster. Statistical Science, 28(3):424 – 446, 2013.
- The frontier of simulation-based inference. Proceedings of the National Academy of Sciences, 117(48):30055–30062, 2020.
- Stochastic Equations in Infinite Dimensions. Cambridge University Press, 2014.
- Flow matching in latent space. arXiv preprint arXiv:2307.08698, 2023.
- The Bayesian approach to inverse problems. arXiv preprint arXiv:1302.6989, 2013.
- Efficient video prediction via sparsely conditioned flow matching. In Proceedings of the IEEE/CVF International Conference on Computer Vision, pages 23263–23274, 2023.
- How to train your neural ODE: the world of Jacobian and kinetic regularization. In International Conference on Machine Learning, pages 3154–3164. PMLR, 2020.
- POT: Python optimal transport. Journal of Machine Learning Research, 22(78):1–8, 2021. URL http://jmlr.org/papers/v22/20-451.html.
- Inferring atmospheric properties of exoplanets with flow matching and neural importance sampling. arXiv preprint arXiv:2312.08295, 2023.
- Generative adversarial nets. Advances in Neural Information Processing Systems, 27, 2014.
- Denoising diffusion probabilistic models. Advances in Neural Information Processing Systems, 33:6840–6851, 2020.
- Conditional optimal transport on function spaces. arXiv preprint arXiv:2311.05672, 2023.
- Manifold interpolating optimal-transport flows for trajectory inference. Advances in Neural Information Processing Systems, 35:29705–29718, 2022.
- Extended flow matching: a method of conditional generation with generalized continuity equation. arXiv preprint arXiv:2402.18839, 2024.
- Image-to-image translation with conditional adversarial networks. In Proceedings of the IEEE/CVF Conference on Computer Vision and Pattern Recognition, 2017.
- Diffusion generative models in infinite dimensions. arXiv preprint arXiv:2212.00886, 2022.
- Functional flow matching. arXiv preprint arXiv:2305.17209, 2023.
- Adam: A method for stochastic optimization. arXiv preprint arXiv:1412.6980, 2014.
- Auto-encoding variational Bayes. arXiv preprint arXiv:1312.6114, 2013.
- Neural optimal transport. arXiv preprint arXiv:2201.12220, 2022.
- Minimizing trajectory curvature of ode-based generative models. In International Conference on Machine Learning, pages 18957–18973. PMLR, 2023.
- Fourier neural operator for parametric partial differential equations. arXiv preprint arXiv:2010.08895, 2020.
- Score-based diffusion models in function space. arXiv preprint arXiv:2302.07400, 2023.
- Flow matching for generative modeling. In The Eleventh International Conference on Learning Representations, 2022.
- Unsupervised image-to-image translation networks. Advances in Neural Information Processing Systems, 30, 2017.
- Flow straight and fast: Learning to generate and transfer data with rectified flow. arXiv preprint arXiv:2209.03003, 2022.
- Optimal transport mapping via input convex neural networks. In International Conference on Machine Learning, pages 6672–6681. PMLR, 2020.
- Robert J McCann. A convexity principle for interacting gases. Advances in Mathematics, 128(1):153–179, 1997.
- K Nazarpour and M Chen. Handwritten Chinese Numbers. 1 2017. doi: 10.17634/137930-3. URL https://data.ncl.ac.uk/articles/dataset/Handwritten_Chinese_Numbers/10280831.
- A computational framework for solving Wasserstein Lagrangian flows. arXiv preprint arXiv:2310.10649, 2023.
- Ot-flow: Fast and accurate continuous normalizing flows via optimal transport. In Proceedings of the AAAI Conference on Artificial Intelligence, pages 9223–9232, 2021.
- Image-to-image translation: Methods and applications. IEEE Transactions on Multimedia, 24:3859–3881, 2021.
- Normalizing flows for probabilistic modeling and inference. Journal of Machine Learning Research, 22(57):1–64, 2021.
- Multisample flow matching: Straightening flows with minibatch couplings. arXiv preprint arXiv:2304.14772, 2023a.
- Neural optimal transport with lagrangian costs. In ICML Workshop on New Frontiers in Learning, Control, and Dynamical Systems, 2023b.
- Learning transferable visual models from natural language supervision. In International Conference on Machine Learning, pages 8748–8763. PMLR, 2021.
- U-net: Convolutional networks for biomedical image segmentation. In Medical image computing and computer-assisted intervention–MICCAI 2015: 18th international conference, Munich, Germany, October 5-9, 2015, proceedings, part III 18, pages 234–241. Springer, 2015.
- Filippo Santambrogio. Optimal transport for applied mathematicians. Birkäuser, NY, 55(58-63):94, 2015.
- Score-based generative modeling through stochastic differential equations. arXiv preprint arXiv:2011.13456, 2020.
- 2-Wasserstein approximation via restricted convex potentials with application to improved training for GANs. arXiv preprint arXiv:1902.07197, 2019.
- Trajectorynet: A dynamic optimal transport network for modeling cellular dynamics. In International Conference on Machine Learning, pages 9526–9536. PMLR, 2020.
- Improving and generalizing flow-based generative models with minibatch optimal transport. In ICML Workshop on New Frontiers in Learning, Control, and Dynamical Systems, 2023.
- Cédric Villani et al. Optimal Transport: Old and New, volume 338. Springer, 2009.
- Efficient neural network approaches for conditional optimal transport with applications in Bayesian inference. arXiv preprint arXiv:2310.16975, 2023.
- Unpaired image-to-image translation using cycle-consistent adversarial networks. In Proceedings of the IEEE/CVF Conference on Computer Vision and Pattern Recognition, pages 2223–2232, 2017.