Multiple Extremal Integrals
Shuyang Bai, Jiemiao Chen
TL;DR
This work develops a comprehensive theory of multiple extremal integrals $I_k^e(f)$ driven by independently scattered $\alpha$-Fréchet random sup measures. It introduces product random sup measures $M_\alpha^{(k)}$ on off-diagonal spaces, provides a LePage-type representation, and derives integrability, convergence, tail behavior, and independence results, including a product formula and max-infinitely divisible structure. The authors also extend extreme-value models to a multi-regenerative setting, unveiling phase transitions in extremal clustering and macroscopic limits governed by the interaction of renewal sets. Collectively, the results advance multi-argument extreme value theory, offering a rigorous framework for analyzing joint extremes, dependence, and clustering in high-order extremal integrals and related stationary models.
Abstract
We introduce the notion of multiple extremal integrals as an extension of single extremal integrals, which have played important roles in extreme value theory. The multiple extremal integrals are formulated in terms of a product-form random sup measure derived from the $α$-Fréchet random sup measure. We establish a LePage-type representation similar to that used for multiple sum-stable integrals, which have been extensively studied in the literature. This approach allows us to investigate the integrability, tail behavior, and independence properties of multiple extremal integrals. Additionally, we discuss an extension of a recently proposed stationary model that exhibits an unusual extremal clustering phenomenon, now constructed using multiple extremal integrals.
