用神经网络重加权跳变过程,实现复杂跳跃现象的高效贝叶斯推断。
Variational Inference for Lévy Process-Driven SDEs via Neural Tilting

- 用神经网络对莱维测度进行指数倾斜,构建灵活的变分分布。
- 在真实和合成数据上准确捕捉跳跃动态,优于传统高斯假设方法。
- 适合金融、气候等存在极端事件的领域,尤其关注跳跃建模的研究者。
建模极端事件与重尾现象是金融、气候科学及安全关键AI中构建可靠预测系统的核心。虽然莱维过程能自然描述跳跃与重尾,但现有方法下莱维驱动随机微分方程(SDE)的贝叶斯推断仍难以处理:蒙特卡洛方法虽严谨但缺乏可扩展性,而神经变分推断虽高效却依赖高斯假设,无法捕捉不连续性。本文提出一种神经指数倾斜框架,用于莱维驱动SDE的变分推断。该方法通过神经网络对莱维测度进行指数重加权,构造灵活的变分族,在保留原始过程跳跃结构的同时保持计算可处理性。为实现高效推断,我们设计了二次型神经参数化,获得倾斜测度的闭式归一化;采用条件高斯表示稳定过程以支持模拟;并引入对称感知蒙特卡洛估计器以实现可扩展优化。实验表明,该方法在合成与真实数据上均能准确捕捉跳跃动态,且在高斯变分方法失效的场景下仍能提供可靠的后验推断。
原文摘要 · Abstract (English)
Modelling extreme events and heavy-tailed phenomena is central to building reliable predictive systems in domains such as finance, climate science, and safety-critical AI. While Lévy processes provide a natural mathematical framework for capturing jumps and heavy tails, Bayesian inference for Lévy-driven stochastic differential equations (SDEs) remains intractable with existing methods: Monte Carlo approaches are rigorous but lack scalability, whereas neural variational inference methods are efficient but rely on Gaussian assumptions that fail to capture discontinuities. We address this tension by introducing a neural exponential tilting framework for variational inference in Lévy-driven SDEs. Our approach constructs a flexible variational family by exponentially reweighting the Lévy measure using neural networks. This parametrization preserves the jump structure of the underlying process while remaining computationally tractable. To enable efficient inference, we develop a quadratic neural parametrization that yields closed-form normalization of the tilted measure, a conditional Gaussian representation for stable processes that facilitates simulation, and symmetry-aware Monte Carlo estimators for scalable optimization. Empirically, we demonstrate that the method accurately captures jump dynamics and yields reliable posterior inference in regimes where Gaussian-based variational approaches fail, on both synthetic and real-world datasets.
Thank you to arXiv for use of its open access interoperability. PaperDance 不是 arXiv 官方产品;中文卡片由大模型生成,请以原文为准。