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Probability Seminar

Event Type
Seminar/Symposium
Sponsor
Department of Mathematics
Location
1057 Lincoln Hall
Date
Aug 8, 2023   2:00 - 2:50 pm  
Speaker
Albert Fisher (University of Sao Paulo)
Views
9

Title:  Dynamical cohomology and Benford's first-digit law for the partial quotients of continued fractions. 

Abstract:  In a new preprint with Xuan Zhang, we give a proof of  Benford's law for the partial quotients $q_n$ of the continued fraction expansion of a.e. real number $x\in (0,1)$. In this talk, I will first review the meaning of cohomology in ergodic theory, specifically for circle-valued skew product transformations, building on the work of Furstenberg. This leads to a characterization of those stationary processes for which the partial sums are uniformly distributed mod 1(if and only if a coboundary condition is satisfied). In the paper, we examine this condition for certain Gibbs-Markov maps and show that $\log q_n$  can be well enough approximated by such processes to yield Benford's law for $q_n$ itself.

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