Universal exponential pointwise convergence for weighted multiple ergodic averages over $ \mathbb{T}^\infty $

التفاصيل البيبلوغرافية
العنوان: Universal exponential pointwise convergence for weighted multiple ergodic averages over $ \mathbb{T}^\infty $
المؤلفون: Tong, Zhicheng, Li, Yong
سنة النشر: 2024
المجموعة: Mathematics
مصطلحات موضوعية: Mathematics - Dynamical Systems, 37A25, 37A30, 37A46
الوصف: By employing an accelerated weighting method, we establish arbitrary polynomial and exponential pointwise convergence for multiple ergodic averages under general conditions in both discrete and continuous settings, involving quasi-periodic and almost periodic cases, which breaks the well known slow convergence rate observed in classical ergodic theory. We also present joint Diophantine rotations as explicit applications. Especially, in the sense that excluding nearly rational rotations with zero measure, we demonstrate that the pointwise exponential convergence is universal via analytic observables, even when multiplicatively averaging over the infinite-dimensional torus $ \mathbb{T}^\infty $, utilizing a novel truncated approach. Moreover, by constructing counterexamples concerning with multiple ergodicity, we highlight the irremovability of the joint nonresonance and establish the optimality of our weighting method in preserving rapid convergence. We also provide numerical simulations with analysis to further illustrate our results.
Comment: 36pages. Comments are welcome!
نوع الوثيقة: Working Paper
URL الوصول: http://arxiv.org/abs/2405.02866
رقم الأكسشن: edsarx.2405.02866
قاعدة البيانات: arXiv