A Kinetic Energy Perspective of Flow Matching

Fuente: arXiv
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Main Authors: Li, Ziyun, Hu, Huancheng, Lim, Soon Hoe, Li, Xuyu, Gao, Fei, Diao, Enmao, Ding, Zezhen, Vazirgiannis, Michalis, Bostrom, Henrik
Format: Preprint
Published: 2026
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author Li, Ziyun
Hu, Huancheng
Lim, Soon Hoe
Li, Xuyu
Gao, Fei
Diao, Enmao
Ding, Zezhen
Vazirgiannis, Michalis
Bostrom, Henrik
author_facet Li, Ziyun
Hu, Huancheng
Lim, Soon Hoe
Li, Xuyu
Gao, Fei
Diao, Enmao
Ding, Zezhen
Vazirgiannis, Michalis
Bostrom, Henrik
contents Flow-based generative models can be viewed through a physics lens: sampling transports a particle from noise to data by integrating a learned velocity field, and each sample corresponds to a trajectory with its own dynamical effort. Motivated by classical mechanics, we introduce Kinetic Path Energy (KPE), an action-like, per-sample diagnostic that measures the accumulated kinetic effort along an ordinary differential equation (ODE) trajectory. Empirically, KPE exhibits two robust correspondences: {i} higher KPE predicts stronger semantic fidelity; {ii} high-KPE trajectories land in sparse representation regions. We further provide theoretical guarantees linking trajectory energy to data sparsity. Paradoxically, this correlation is non-monotonic. At sufficiently high energy, generation can degenerate into memorization. Leveraging the closed-form formula of empirical flow matching, we show that extreme energies drive trajectories toward near-copies of training examples. This yields a Goldilocks principle and motivates Kinetic Trajectory Shaping (KTS), a training-free two-phase inference strategy that boosts early motion and enforces a late-time soft landing, reducing memorization and improving generation quality across benchmark tasks.
format Preprint
id arxiv_https___arxiv_org_abs_2602_07928
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle A Kinetic Energy Perspective of Flow Matching
Li, Ziyun
Hu, Huancheng
Lim, Soon Hoe
Li, Xuyu
Gao, Fei
Diao, Enmao
Ding, Zezhen
Vazirgiannis, Michalis
Bostrom, Henrik
Machine Learning
Artificial Intelligence
Flow-based generative models can be viewed through a physics lens: sampling transports a particle from noise to data by integrating a learned velocity field, and each sample corresponds to a trajectory with its own dynamical effort. Motivated by classical mechanics, we introduce Kinetic Path Energy (KPE), an action-like, per-sample diagnostic that measures the accumulated kinetic effort along an ordinary differential equation (ODE) trajectory. Empirically, KPE exhibits two robust correspondences: {i} higher KPE predicts stronger semantic fidelity; {ii} high-KPE trajectories land in sparse representation regions. We further provide theoretical guarantees linking trajectory energy to data sparsity. Paradoxically, this correlation is non-monotonic. At sufficiently high energy, generation can degenerate into memorization. Leveraging the closed-form formula of empirical flow matching, we show that extreme energies drive trajectories toward near-copies of training examples. This yields a Goldilocks principle and motivates Kinetic Trajectory Shaping (KTS), a training-free two-phase inference strategy that boosts early motion and enforces a late-time soft landing, reducing memorization and improving generation quality across benchmark tasks.
title A Kinetic Energy Perspective of Flow Matching
topic Machine Learning
Artificial Intelligence
url https://arxiv.org/abs/2602.07928