ALGEBRAIC COMBINATORICS

no. 5

Random walk on the symplectic forms over a finite field
Algebraic Combinatorics, Volume 3 (2020) no. 5, pp. 1165-1181.

Random transvections generate a walk on the space of symplectic forms on F q 2n . The main result is to establish cutoff for this Markov chain. After n+c steps, the walk is close to uniform while before n-c steps, it is far from uniform. The upper bound is proved by explicitly finding and bounding the eigenvalues of the random walk. The lower bound is found by showing that the support of the walk is exponentially small if only n-c steps are taken. The result can be viewed as a q-deformation of a result of Diaconis and Holmes on a random walk on matchings.

Received: 2019-11-20
Revised: 2020-06-09
Accepted: 2020-06-09
Published online: 2020-10-12
DOI: https://doi.org/10.5802/alco.131
Classification: 60J10,  60B15,  20C33
Keywords: Markov Chain, Gelfand Pair, Characteristic map, Symmetric functions 
@article{ALCO_2020__3_5_1165_0,
     author = {He, Jimmy},
     title = {Random walk on the symplectic forms over a finite field},
     journal = {Algebraic Combinatorics},
     pages = {1165--1181},
     publisher = {MathOA foundation},
     volume = {3},
     number = {5},
     year = {2020},
     doi = {10.5802/alco.131},
     language = {en},
     url = {alco.centre-mersenne.org/item/ALCO_2020__3_5_1165_0/}
}
He, Jimmy. Random walk on the symplectic forms over a finite field. Algebraic Combinatorics, Volume 3 (2020) no. 5, pp. 1165-1181. doi : 10.5802/alco.131. https://alco.centre-mersenne.org/item/ALCO_2020__3_5_1165_0/

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