Papers › Diffusion Bridge Mixture Transports, Schrödinger Bridge Problems and Generative Modeling

Diffusion Bridge Mixture Transports, Schrödinger Bridge Problems and Generative Modeling

3 Apr 2023arXiv:2304.00917archive 2025-07-28

Stefano Peluchetti

The dynamic Schr\"odinger bridge problem seeks a stochastic process that defines a transport between two target probability measures, while optimally satisfying the criteria of being closest, in terms of Kullback-Leibler divergence, to a reference process. We propose a novel sampling-based iterative algorithm, the iterated diffusion bridge mixture (IDBM) procedure, aimed at solving the dynamic Schr\"odinger bridge problem. The IDBM procedure exhibits the attractive property of realizing a valid transport between the target probability measures at each iteration. We perform an initial theoretical investigation of the IDBM procedure, establishing its convergence properties. The theoretical findings are complemented by numerical experiments illustrating the competitive performance of the IDBM procedure. Recent advancements in generative modeling employ the time-reversal of a diffusion process to define a generative process that approximately transports a simple distribution to the data distribution. As an alternative, we propose utilizing the first iteration of the IDBM procedure as an approximation-free method for realizing this transport. This approach offers greater flexibility in selecting the generative process dynamics and exhibits accelerated training and superior sample quality over larger discretization intervals. In terms of implementation, the necessary modifications are minimally intrusive, being limited to the training loss definition.

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stepelu/idbm-pytorch officialmentioned in papermentioned on GitHubpytorch report
bw-park/DBFS mentioned on GitHubpytorch report

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drift_target stepelu/idbm-pytorch/idbm/idbm.py official repository ran · our draft was wrong fingerprinted MIT (permissive) · 7229a9890e128fd0 · report
idbm_target stepelu/idbm-pytorch/idbm/idbm.py official repository ran · violated contract fingerprinted MIT (permissive) · bf4f74f9de5c01ba · report
sample_bridge stepelu/idbm-pytorch/idbm/idbm.py official repository ran · our draft was wrong fingerprinted MIT (permissive) · 8eb6a9b97377acf2 · report
a_ bw-park/DBFS/dbfs/dbfs_afhq.py community (archive-listed) ran · honoured contract MIT (permissive) · c367035d90c55cbe · report
a_2 bw-park/DBFS/dbfs/dbfs_afhq.py community (archive-listed) ran · honoured contract MIT (permissive) · 7e95e0e24cfddb51 · report
count_parameters identical code first harvested elsewhere ran · honoured contract licence of this copy not recorded · f6b944f50d3f15ae · report

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