The Velocity Deficit: Initial Energy Injection for Flow Matching

Fuente: arXiv
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Autori principali: Li, Linze, Hong, Zong-Wei, Zhang, Shen, Lin, Bo, Li, Jinglun, Tang, Yao, Liang, Jiajun
Natura: Preprint
Pubblicazione: 2026
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author Li, Linze
Hong, Zong-Wei
Zhang, Shen
Lin, Bo
Li, Jinglun
Tang, Yao
Liang, Jiajun
author_facet Li, Linze
Hong, Zong-Wei
Zhang, Shen
Lin, Bo
Li, Jinglun
Tang, Yao
Liang, Jiajun
contents While Flow Matching theoretically guarantees constant-velocity trajectories, we identify a critical breakdown in high-dimensional practice: the Velocity Deficit. We show that the MSE objective systematically underestimates velocity magnitude, causing generated samples to fail to reach the data manifold-a phenomenon we term Integration Lag. To rectify this, we propose Initial Energy Injection, instantiated via two complementary methods: the training-based Magnitude-Aware Flow Matching (MAFM) and the training-free Scale Schedule Corrector (SSC). Both are grounded in our discovery of a crucial asymmetry: velocity contraction causes harmful kinetic stagnation at the trajectory's start, yet acts as a beneficial denoising mechanism at its end. Empirically, SSC yields significant efficiency gains with zero retraining and just one line of code. On ImageNet-1k (256x256), it improves FID by 44.6% (from 13.68 to 7.58) and achieves a 5x speedup, enabling a 50-step generator (FID 7.58) to beat a 250-step baseline (FID 8.65). Furthermore, our methods generalize to Text-to-Image tasks and high-resolution generation, improving FID on MS-COCO by ~22%.
format Preprint
id arxiv_https___arxiv_org_abs_2605_14819
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle The Velocity Deficit: Initial Energy Injection for Flow Matching
Li, Linze
Hong, Zong-Wei
Zhang, Shen
Lin, Bo
Li, Jinglun
Tang, Yao
Liang, Jiajun
Computer Vision and Pattern Recognition
While Flow Matching theoretically guarantees constant-velocity trajectories, we identify a critical breakdown in high-dimensional practice: the Velocity Deficit. We show that the MSE objective systematically underestimates velocity magnitude, causing generated samples to fail to reach the data manifold-a phenomenon we term Integration Lag. To rectify this, we propose Initial Energy Injection, instantiated via two complementary methods: the training-based Magnitude-Aware Flow Matching (MAFM) and the training-free Scale Schedule Corrector (SSC). Both are grounded in our discovery of a crucial asymmetry: velocity contraction causes harmful kinetic stagnation at the trajectory's start, yet acts as a beneficial denoising mechanism at its end. Empirically, SSC yields significant efficiency gains with zero retraining and just one line of code. On ImageNet-1k (256x256), it improves FID by 44.6% (from 13.68 to 7.58) and achieves a 5x speedup, enabling a 50-step generator (FID 7.58) to beat a 250-step baseline (FID 8.65). Furthermore, our methods generalize to Text-to-Image tasks and high-resolution generation, improving FID on MS-COCO by ~22%.
title The Velocity Deficit: Initial Energy Injection for Flow Matching
topic Computer Vision and Pattern Recognition
url https://arxiv.org/abs/2605.14819