2024/01/11 by Gu, Haotian, Zhang, Zhenyuan
#FOS: Mathematics #Probability (math.PR)
paper · doi:10.48550/arxiv.2401.05681
We investigate the low moments 𝔼[|AN|2q], 02q. As a consequence, we establish the universality for the tightness of the normalized secular coefficients AN(log(1+N))1/4, generalizing a result of Najnudel, Paquette, and Simm. Another corollary is the almost sure regularity of some critical non-Gaussian holomorphic chaos in appropriate Sobolev spaces. Moreover, we characterize the asymptotics of 𝔼[|AN|2q] for |Xk| following a stretched exponential distribution with an arbitrary scale parameter, which exhibits a completely different behavior and underlying mechanism from the Gaussian universality regime. As a result, we unveil a double-layer phase transition around the critical case of exponential tails. Our proofs combine Harper's robust approach with a careful analysis of the (possibly random) leading terms in the monomial decomposition of AN.