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Anomalous time-scaling of extreme events in infinite systems and Birkhoff sums of infinite observables

Galatolo, Stefano ; Holland, Mark ; Persson, Tomas LU orcid and Zhang, Yiwei (2021) In Discrete and Continuous Dynamical Systems- Series A 41(4). p.1799-1841
Abstract

We establish quantitative results for the statistical behaviour of infinite systems. We consider two kinds of infinite system: i) a conservative dynamical system (f, X, µ) preserving a σ-finite measure µ such that µ(X) = ∞; ii) the case where µ is a probability measure but we consider the statistical behaviour of an observable φ: X → [0, ∞) which is non-integrable: R φ dµ = ∞. In the first part of this work we study the behaviour of Birkhoff sums of systems of the kind ii). For certain weakly chaotic systems, we show that these sums can be strongly oscillating. However, if the system has superpolynomial decay of correlations or has a Markov structure, then we show this oscillation cannot happen. In this case we prove a general relation... (More)

We establish quantitative results for the statistical behaviour of infinite systems. We consider two kinds of infinite system: i) a conservative dynamical system (f, X, µ) preserving a σ-finite measure µ such that µ(X) = ∞; ii) the case where µ is a probability measure but we consider the statistical behaviour of an observable φ: X → [0, ∞) which is non-integrable: R φ dµ = ∞. In the first part of this work we study the behaviour of Birkhoff sums of systems of the kind ii). For certain weakly chaotic systems, we show that these sums can be strongly oscillating. However, if the system has superpolynomial decay of correlations or has a Markov structure, then we show this oscillation cannot happen. In this case we prove a general relation between the behaviour of φ, the local dimension of µ, and the scaling rate of the growth of Birkhoff sums of φ as time tends to infinity. We then establish several important consequences which apply to infinite systems of the kind i). This includes showing anomalous scalings in extreme event limit laws, or entrance time statistics. We apply our findings to non-uniformly hyperbolic systems preserving an infinite measure, establishing anomalous scalings for the power law behaviour of entrance times (also known as logarithm laws), dynamical Borel-Cantelli lemmas, almost sure growth rates of extremes, and dynamical run length functions.

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author
; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Birkhoff sum, Borel-Cantelli, Conservative dynamics, Extreme values, Hitting time, Infinite invariant measure, Intermittent system, Logarithm law, Run length
in
Discrete and Continuous Dynamical Systems- Series A
volume
41
issue
4
pages
43 pages
publisher
American Institute of Mathematical Sciences
external identifiers
  • scopus:85101088935
ISSN
1078-0947
DOI
10.3934/dcds.2020341
language
English
LU publication?
yes
id
33c6682e-da93-4c8d-b6bf-1dd3747ec721
date added to LUP
2022-01-12 15:28:27
date last changed
2022-04-27 07:06:19
@article{33c6682e-da93-4c8d-b6bf-1dd3747ec721,
  abstract     = {{<p>We establish quantitative results for the statistical behaviour of infinite systems. We consider two kinds of infinite system: i) a conservative dynamical system (f, X, µ) preserving a σ-finite measure µ such that µ(X) = ∞; ii) the case where µ is a probability measure but we consider the statistical behaviour of an observable φ: X → [0, ∞) which is non-integrable: R φ dµ = ∞. In the first part of this work we study the behaviour of Birkhoff sums of systems of the kind ii). For certain weakly chaotic systems, we show that these sums can be strongly oscillating. However, if the system has superpolynomial decay of correlations or has a Markov structure, then we show this oscillation cannot happen. In this case we prove a general relation between the behaviour of φ, the local dimension of µ, and the scaling rate of the growth of Birkhoff sums of φ as time tends to infinity. We then establish several important consequences which apply to infinite systems of the kind i). This includes showing anomalous scalings in extreme event limit laws, or entrance time statistics. We apply our findings to non-uniformly hyperbolic systems preserving an infinite measure, establishing anomalous scalings for the power law behaviour of entrance times (also known as logarithm laws), dynamical Borel-Cantelli lemmas, almost sure growth rates of extremes, and dynamical run length functions.</p>}},
  author       = {{Galatolo, Stefano and Holland, Mark and Persson, Tomas and Zhang, Yiwei}},
  issn         = {{1078-0947}},
  keywords     = {{Birkhoff sum; Borel-Cantelli; Conservative dynamics; Extreme values; Hitting time; Infinite invariant measure; Intermittent system; Logarithm law; Run length}},
  language     = {{eng}},
  number       = {{4}},
  pages        = {{1799--1841}},
  publisher    = {{American Institute of Mathematical Sciences}},
  series       = {{Discrete and Continuous Dynamical Systems- Series A}},
  title        = {{Anomalous time-scaling of extreme events in infinite systems and Birkhoff sums of infinite observables}},
  url          = {{http://dx.doi.org/10.3934/dcds.2020341}},
  doi          = {{10.3934/dcds.2020341}},
  volume       = {{41}},
  year         = {{2021}},
}