Abstract : We study the iteration of the process "a particle jumps to the right" in permutations. We prove that the set of permutations obtained in this model after a given number of iterations from the identity is a class of pattern avoiding permutations. We characterize the elements of the basis of this class and we enumerate these "forbidden minimal patterns" by giving their bivariate exponential generating function: we achieve this via a catalytic variable, the number of left-to-right maxima. We show that this generating function is a D-finite function satisfying a nice differential equation of order 2. We give some congruence properties for the coefficients of this generating function, and we show that their asymptotics involves a rather unusual algebraic exponent (the golden ratio (1 + √ 5)/2) and some unusual closed-form constants. We end by proving a limit law: a forbidden pattern of length n has typically (ln n)/ √ 5 left-to-right maxima, with Gaussian fluctuations.
https://hal.archives-ouvertes.fr/hal-01236582
Contributeur : Cyril Banderier
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Soumis le : jeudi 9 février 2017 - 08:11:54
Dernière modification le : mardi 6 février 2018 - 15:56:16
Document(s) archivé(s) le : mercredi 10 mai 2017 - 12:38:43
