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Related papers: On pointwise ergodic theorems for infinite measure

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We consider ergodic multiflows on a probability space. The general theorem on universal averaging for multiflows is applied to averaging along manifolds in $R^n$.

Dynamical Systems · Mathematics 2026-05-14 I. V. Bychkov , V. V. Ryzhikov

Let $\mathcal H$ be an infinite-dimensional Hilbert space, and let $\mathcal B(\mathcal H)$ ($\mathcal K(\mathcal H)$) be the $C^*$-algebra of bounded (respectively, compact) linear operators in $\mathcal H$. Let $(E,\|\cdot\|_E)$ be a…

Functional Analysis · Mathematics 2019-03-05 Aziz Azizov , Vladimir Chilin , Semyon Litvinov

The idea of a parsing of a stationary process according to a collection of words is introduced, and the basic framework required for the asymptotic analysis of these parsings is presented. We demonstrate how the pointwise ergodic theorem…

Dynamical Systems · Mathematics 2025-02-13 Matan Tal

Urbanik's theorem for a Poisson process on an infinite measure space (X, A, $\mu$) relates integrability of stochastic integrals to a particular Orlicz function space L$\Phi$ ($\mu$) on which the L1-norm of the Poisson process induces a…

Dynamical Systems · Mathematics 2023-06-27 Emmanuel Roy

Given any amenable group $G$ (with a left Haar measure $|\cdot|$ or $dg$), we can select out a \textit{F{\o}lner subnet} $\{F_\theta,\theta\in\Theta\}$ from any left F{\o}lner net in $G$, which is \textit{$L^\infty$-admissible}, namely, for…

Dynamical Systems · Mathematics 2016-06-17 Xiongping Dai

Under suitable hypotheses we establish a quantitative pointwise ergodic theorem which applies to trimmed Birkhoff sums of weakly integrable functions.

Dynamical Systems · Mathematics 2019-02-20 Alan Haynes

The main result of this note, Theorem 2, is the following: a Borel measure on the space of infinite Hermitian matrices, that is invariant under the action of the infinite unitary group and that admits well-defined projections onto the…

Dynamical Systems · Mathematics 2011-08-16 Alexander I. Bufetov

We present a simple way to produce good weights for several types of ergodic theorem including the Wiener-Wintner type multiple return time theorem and the multiple polynomial ergodic theorem. These weights are deterministic and come from…

Dynamical Systems · Mathematics 2014-05-01 Tanja Eisner

In the present paper we consider a von Neumann algebra M with a faithful normal semi-finite trace $\t$, and $\{\alpha_ t\} $ a strongly continuous extension to $L^p(M,\t)$ of a semigroup of absolute contractions on $L^1 (M,\tau)$. By means…

Operator Algebras · Mathematics 2007-11-21 Farrukh Mukhamedov , Abdusalom Karimov

Let f be a self-map of a compact manifold M, admitting an global SRB measure \mu. For a continuous test function \phi on M and a constant \alpha>0, consider the set of the initial points for which the Birkhoff time averages of the function…

Dynamical Systems · Mathematics 2011-12-30 Victor Kleptsyn , Dmitry Ryzhov

In this article, we establish weighted strong and weak type inequalities for non-commutative square functions that naturally arise in the analysis of differences between ball averages and martingale sequences within the framework of group…

Functional Analysis · Mathematics 2026-01-05 Panchugopal Bikram , Diptesh Saha

Let $U$ be a unitary operator acting on the Hilbert space H, and $\alpha:\{1,..., m\}\mapsto\{1,..., k\}$ a partition of the set $\{1,..., m\}$. We show that the ergodic average $$ \frac{1}{N^{k}}\sum_{n_{1},...,n_{k}=0}^{N-1}…

Functional Analysis · Mathematics 2007-05-23 francesco fidaleo

We introduce a natural equivalence relation on the space $\sH_0$ of horofunctions of a word hyperbolic group that take the value 0 at the identity. We show that there are only finitely many ergodic measures that are invariant under this…

Dynamical Systems · Mathematics 2008-07-15 Lewis Phylip Bowen

We study the ergodic and statistical properties of a class of maps of the circle and of the interval of Lorenz type which present indifferent fixed points and points with unbounded derivative. These maps have been previously investigated in…

Dynamical Systems · Mathematics 2008-12-16 Giampaolo Cristadoro , Nicolai Haydn , Philippe Marie , Sandro Vaienti

Ergodic optimization aims to describe dynamically invariant probability measures that maximize the integral of a given function. The Dyck and Motzkin shifts are well-known examples of transitive subshifts over a finite alphabet that are not…

Dynamical Systems · Mathematics 2024-07-01 Mao Shinoda , Hiroki Takahasi , Kenichiro Yamamoto

We study the optimization of ergodic averages for multi-valued dynamical systems, i.e. where points may have multiple different forward orbits. Under upper semi-continuity assumptions, we show that the maximum space average with respect to…

Dynamical Systems · Mathematics 2025-06-03 Oliver Jenkinson , Xiaoran Li , Yuexin Liao , Yiwei Zhang

We provide an exposition of the proofs of Bourgain's polynomial ergodic theorems. The focus is on the motivation and intuition behind his arguments.

Dynamical Systems · Mathematics 2023-01-05 Ben Krause

The transference theory for Lp spaces of Calderon, Coifman, and Weiss is a powerful tool with many applications to singular integrals, ergodic theory, and spectral theory of operators. Transference methods afford a unified approach to many…

Functional Analysis · Mathematics 2008-02-03 Nakhlé Asmar , Stephen J. Montgomery-Smith , Sadahiro Saeki

For $c\in(1,2)$ we consider the following operators \[ \mathcal{C}_{c}f(x) = \sup_{\lambda \in [-1/2,1/2)}\bigg| \sum_{n \neq 0}f(x-n) \frac{e^{2\pi i\lambda \lfloor |n|^{c} \rfloor}}{n}\bigg|\text{,}\quad \mathcal{C}^{\mathsf{sgn}}_{c}f(x)…

Dynamical Systems · Mathematics 2026-03-17 Leonidas Daskalakis , Anastasios Fragkos

This brief pedagogical note re-proves a simple theorem on the convergence, in $L_2$ and in probability, of time averages of non-stationary time series to the mean of expectation values. The basic condition is that the sum of covariances…

Probability · Mathematics 2022-03-22 Cosma Rohilla Shalizi