发表机构
Boston University(波士顿大学)
机构由 AI 辅助整理,请以论文原文为准。AI 中文总结
本文建立高斯从属随机变量部分和的 $L^2$ 最大不等式,在仅有限方差条件下证明离散与连续时间的 Breuer--Major--Donsker 原理,并处理非平稳自相似情形的临界极限。
AI 中文摘要
本文建立了高斯从属随机变量部分和的最大值的 $L^2$ 最大不等式。具体而言,设 $f:\mathbb{R}\to\mathbb{R}$ 属于 $L^2(\gamma)$ 且其 Hermite 秩至少为 $d$,其中 $\gamma$ 表示标准高斯测度。若底层高斯族(具有标准正态边缘分布)的协方差矩阵满足一致的 $d$ 次幂行界 $K$,则最大部分和的 $L^2$ 范数以 $C_{d,K}\sqrt n\\,\\|f\\|_{L^2(\gamma)}$ 为界。常数 $C_{d,K}$ 与 $(f,n)$ 无关,且仅通过 $K$ 依赖于协方差结构。作为推论,我们的 $L^2$ 最大不等式在路径范数下一致地控制 Hermite 尾部。在离散时间情形,这仅在有限方差假设下即可得到 Breuer--Major--Donsker 原理,去除了 Nourdin 和 Nualart(Probab. Theory Related Fields, 2020)额外的 $L^{2+}$ 可积性假设,以及 Mansanarez、Poly 和 Zheng(arXiv:2607.11469)的预测理论或抽取假设。在连续时间情形,我们同样仅在有限方差下获得 Breuer--Major--Donsker 原理,去除了 Campese、Nourdin 和 Nualart(Ann. Probab., 2020)的额外矩假设。对于该文考虑的非平稳自相似情形,我们在次临界区域去除了同样的额外矩假设,而一个独立的 leading-chaos 论证给出了相应的对数归一化临界极限。
英文摘要
In this paper, we establish an $L^2$ maximal inequality for partial sums of Gaussian-subordinated random variables. More precisely, let $f:\mathbb{R}\to\mathbb{R}$ belong to $L^2(γ)$ and have Hermite rank at least $d$, where $γ$ denotes the standard Gaussian measure. If the covariance matrix of the underlying Gaussian family, with standard normal marginals, satisfies a uniform $d$th-power row bound $K$, then the $L^2$ norm of the maximal partial sum is bounded by $C_{d,K}\sqrt n\,\|f\|_{L^2(γ)}$. The constant $C_{d,K}$ is independent of $(f,n)$ and depends on the covariance structure only through $K$. As a consequence, our $L^2$ maximal inequality controls Hermite tails uniformly in the path norm. In discrete time, this yields the Breuer--Major--Donsker principle under the sole finite-variance assumption, removing both the additional $L^{2+}$-integrability assumption of Nourdin and Nualart (Probab. Theory Related Fields, 2020) and the prediction-theoretic or decimation assumptions of Mansanarez, Poly, and Zheng (arXiv:2607.11469). In continuous time, we likewise obtain the Breuer--Major--Donsker principle under finite variance alone, removing the additional moment assumption of Campese, Nourdin, and Nualart (Ann. Probab., 2020). For the nonstationary self-similar setting considered there, we remove the same extra moment assumption in the subcritical regime, while a separate leading-chaos argument yields the corresponding logarithmically normalized critical limit. [Abstract shorten to meet arXiv requirement]