Séminaire Lotharingien de Combinatoire, 93B.6 (2025), 11 pp.

Evita Nestoridi and Alan Yan

Cutoff for the Biased Random Transposition Shuffle

Abstract. We study the biased random transposition shuffle, a natural generalization of the classical random transposition shuffle studied by Diaconis and Shahshahani. Using the representation theory of the symmetric group, we diagonalize the transition matrix of the shuffle. We use these eigenvalues to prove that the shuffle exhibits total variation cutoff at time tN = (1/2b) N log N with window N. We also prove that the limiting distribution of the number of fixed cards near the cutoff time is Poisson.


Received: November 15, 2024. Accepted: February 15, 2025. Final version: April 1, 2025.

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